| 词条 | Ataxia–telangiectasia |
| 释义 |
| name = Ataxia–telangiectasia | synonyms = | image = | caption = | pronounce = | field = | symptoms = | complications = | onset = | duration = | types = | causes = | risks = | diagnosis = | differential = | prevention = | treatment = | medication = | prognosis = | frequency = | deaths = }}Ataxia–telangiectasia (AT or A–T), also referred to as ataxia–telangiectasia syndrome or Louis–Bar syndrome,[1] is a rare, neurodegenerative, autosomal recessive disease causing severe disability. Ataxia refers to poor coordination and telangiectasia to small dilated blood vessels, both of which are hallmarks of the disease.[2] A–T affects many parts of the body:
Symptoms most often first appear in early childhood (the toddler stage) when children begin to sit or walk. Though they usually start walking at a normal age, they wobble or sway when walking, standing still or sitting. In late pre-school and early school age, they develop difficulty moving their eyes in a natural manner from one place to the next (oculomotor apraxia). They develop slurred or distorted speech, and swallowing problems. Some have an increased number of respiratory tract infections (ear infections, sinusitis, bronchitis, and pneumonia). Because not all children develop in the same manner or at the same rate, it may be some years before A–T is properly diagnosed. Most children with A–T have stable neurologic symptoms for the first 4–5 years of life, but begin to show increasing problems in early school years. A–T is caused by a defect in the ATM gene,[3] The protein produced by the ATM gene recognizes that there is a break in dsDNA, recruits other proteins to fix the break, and stops the cell from making new DNA until the repair is complete.[4] The prevalence of A–T is estimated to be as high as 1 in 40,000 to as low as 1 in 300,000 people.[5][6] SymptomsThere is substantial variability in the severity of features of A–T among affected individuals, and at different ages. The following symptoms or problems are either common or important features of A–T:
Many children are initially misdiagnosed as having cerebral palsy. The diagnosis of A–T may not be made until the preschool years when the neurologic symptoms of impaired gait, hand coordination, speech and eye movement appear or worsen, and the telangiectasia first appear. Because A–T is so rare, doctors may not be familiar with the symptoms, or methods of making a diagnosis. The late appearance of telangiectasia may be a barrier to the diagnosis.[7] It may also take some time before doctors consider A–T as a possibility because of the early stability of symptoms and signs.{{citation needed|date=October 2018}} Ataxia and other neurologic problemsThe first indications of A–T usually occur during the toddler years.[8][9] Children start walking at a normal age, but may not improve much from their initial wobbly gait. Sometimes they have problems standing or sitting still and tend to sway backward or from side to side. In primary school years, walking becomes more difficult, and children will use doorways and walls for support. Children with A–T often appear better when running or walking quickly in comparison to when they are walking slowly or standing in one place. Around the beginning of their second decade, children with the more severe ("classic") form of A–T start using a wheelchair for long distances. During school years, children may have increasing difficulty with reading because of impaired coordination of eye movement. At the same time, other problems with fine-motor functions (writing, coloring, and using utensils to eat), and with slurring of speech (dysarthria) may arise. Most of these neurologic problems stop progressing after the age of about 12 – 15 years, though involuntary movements may start at any age and may worsen over time. These extra movements can take many forms, including small jerks of the hands and feet that look like fidgeting (chorea), slower twisting movements of the upper body (athetosis), adoption of stiff and twisted postures (dystonia), occasional uncontrolled jerks (myoclonic jerks), and various rhythmic and non-rhythmic movements with attempts at coordinated action (tremors). TelangiectasiaProminent blood vessels (telangiectasia) over the white (sclera) of the eyes usually occur by the age of 5–8 years, but sometimes appear later or not at all.[10] The absence of telangiectasia does not exclude the diagnosis of A–T. Potentially a cosmetic problem, the ocular telangiectasia do not bleed or itch, though they are sometimes misdiagnosed as chronic conjunctivitis. It is their constant nature, not changing with time, weather or emotion, that marks them as different from other visible blood vessels. Telangiectasia can also appear on sun-exposed areas of skin, especially the face and ears. They occur in the bladder as a late complication of chemotherapy with cyclophosphamide,[11] have been seen deep inside the brain of older people with A–T,[12] and occasionally arise in the liver and lungs.{{citation needed|date=March 2017}} Immune problemsAbout two-thirds of people with A–T have abnormalities of the immune system.[13] The most common abnormalities are low levels of one or more classes of immunoglobulins (IgG, IgA or IgM subclasses), not making antibodies in response to vaccines or infections, and having low numbers of lymphocytes (especially T-lymphocytes) in the blood. Some people have frequent infections of the upper (colds, sinus and ear infections) and lower (bronchitis and pneumonia) respiratory tract. All children with A–T should have their immune systems evaluated to detect those with severe problems that require treatment to minimize the number or severity of infections. Some people with A–T need additional immunizations (especially with pneumonia and influenza vaccines), antibiotics to provide protection (prophylaxis) from infections, and/or infusions of immunoglobulins (gamma globulin). The need for these treatments should be determined by an expert in the field of immunodeficiency or infectious diseases. CancerPeople with A–T have a highly increased incidence (approximately 25% lifetime risk) of cancers, particularly lymphomas and leukemia, but other cancers can occur.[14] When possible, treatment should avoid the use of radiation therapy and chemotherapy drugs that work in a way that is similar to radiation therapy (radiomimetic drugs), as these are particularly toxic for people with A–T. The special problems of managing cancer are sufficiently complicated that treatment should be done only in academic oncology centers and after consultation with physicians who have specific expertise in A–T. Unfortunately, there is no way to predict which individuals will develop cancer. Because leukemia and lymphomas differ from solid tumors in not progressing from solitary to metastatic stages, there is less need to diagnose them early in their appearance. Surveillance for leukemia and lymphoma is thus not helpful, other than considering cancer as a diagnostic possibility whenever possible symptoms of cancer (e.g. persistent swollen lymph glands, unexplained fever) arise. Women who are A–T carriers (who have one mutated copy of the ATM gene), have approximately a two-fold increased risk for the development of breast cancer compared to the general population.[15][16] This includes all mothers of A–T children and some female relatives. Current consensus is that special screening tests are not helpful, but all women should have routine cancer surveillance. SkinA–T can cause features of early aging such as premature graying of the hair. It can also cause vitiligo (an auto-immune disease causing loss of skin pigment resulting in a blotchy “bleach-splashed” look), and warts which can be extensive and recalcitrant to treatment. A small number of people develop a chronic inflammatory skin disease (granulomas).[17] Lung diseaseChronic lung disease develops in more than 25% of people with A–T.[18] Three major types of lung disease can develop: (1) recurrent and chronic sinopulmonary infections; (2) lung disease caused by ineffective cough, swallowing dysfunction, and impaired airway clearance; and (3) restrictive interstitial lung disease. It is common for individuals with A–T to have more than one of these lung conditions. Chronic lung disease can occur because of recurrent lung infections due to immunodeficiency. Individuals with this problem are at risk of developing bronchiectasis, a condition in which bronchial tubes are permanently damaged, resulting in recurrent lower airway infections. Gamma globulin for people with antibody deficiency and/or chronic antibiotic treatment may reduce the problems of infection. Other individuals with A–T have difficulty with taking deep breaths and may have an ineffective cough, making it difficult to clear oral and bronchial secretions. This can lead to prolonged respiratory symptoms following common viral respiratory illnesses. Techniques that allow clearance of mucus can be helpful in some individuals during respiratory illnesses. Some people will develop swallowing problems as they age, increasing their risk of aspiration pneumonia. Recurrent injury to the lungs caused by chronic infections or aspiration may cause lung fibrosis and scarring. This process may be enhanced by inadequate tissue repair in ATM-deficient cells. A small number of individuals develop interstitial lung disease. They have decreased pulmonary reserve, trouble breathing, a need for supplemental oxygen and chronic cough in the absence of lung infections. They may respond to systemic steroid treatment or other drugs to reduce inflammation. Lung function tests (spirometry) should be performed at least annually in children old enough to perform them, influenza and pneumococcal vaccines given to eligible individuals, and sinopulmonary infections treated aggressively to limit the development of chronic lung disease. Feeding, swallowing, and nutritionFeeding and swallowing can become difficult for people with A–T as they get older.[19] Feeding refers to all aspects of eating and drinking, including getting food and liquids to the mouth; swallowing refers to ingestion or what happens after food or liquids enter the mouth. Primary goals for feeding and swallowing are safe, adequate, and enjoyable mealtimes. Involuntary movements may make feeding difficult or messy and may excessively prolong mealtimes. It may be easier to finger feed than use utensils (e.g., spoon or fork). For liquids, it is often easier to drink from a closed container with a straw than from an open cup. Caregivers may need to provide foods or liquids so that self-feeding is possible, or they may need to feed the person with A–T. In general, meals should be completed within approximately 30 minutes. Longer meals may be stressful, interfere with other daily activities, and limit the intake of necessary liquids and nutrients. If swallowing problems (dysphagia) occur, they typically present during the second decade of life. Dysphagia is common because of the neurological changes that interfere with coordination of mouth and pharynx (throat) movements that are needed for safe and efficient swallowing. Coordination problems involving the mouth may make chewing difficult and increase the duration of meals. Problems involving the pharynx may cause liquid, food, and saliva to be inhaled into the airway (aspiration). People with dysphagia may not cough when they aspirate (silent aspiration). Swallowing problems and especially swallowing problems with silent aspiration may cause lung problems due to inability to cough and clear food and liquids from the airway.
Eye and vision
OrthopedicsMany individuals with A–T develop deformities of the feet that compound the difficulty they have with walking due to impaired coordination. Early treatment may slow progression of this deformity. Bracing or surgical correction sometimes improves stability at the ankle sufficient to enable an individual to walk with support, or bear weight during assisted standing transfers from one seat to another. Severe scoliosis is relatively uncommon, but probably does occur more often than in those without A–T. Spinal fusion is only rarely indicated. PathophysiologyHow does loss of the ATM protein create a multisystem disorder?A–T has been described as a genome instability syndrome, a DNA repair disorder and a DNA damage response (DDR) syndrome. ATM, the gene responsible for this multi-system disorder, encodes a protein of the same name which coordinates the cellular response to DNA double strand breaks (DSBs).[21] Radiation therapy, chemotherapy that acts like radiation (radiomimetic drugs) and certain biochemical processes and metabolites can cause DSBs. When these breaks occur, ATM stops the cell from making new DNA (cell cycle arrest) and recruits and activates other proteins to repair the damage. Thus, ATM allows the cell to repair its DNA before the completion of cell division. If DNA damage is too severe, ATM will mediate the process of programmed cell death (apoptosis) to eliminate the cell and prevent genomic instability.[22] Cancer and radiosensitivityIn the absence of the ATM protein, cell-cycle check-point regulation and programmed cell death in response to DSBs are defective. The result is genomic instability which can lead to the development of cancers.[29] Irradiation and radiomimetic compounds induce DSBs which are unable to be repaired appropriately when ATM is absent. Consequently, such agents can prove especially cytotoxic to A–T cells and people with A–T. Delayed pubertal development (gonadal dysgenesis)Infertility is often described as a characteristic of A–T. Whereas this is certainly the case for the mouse model of A–T,[30] in humans it may be more accurate to characterize the reproductive abnormality as gonadal atrophy or dysgenesis characterized by delayed pubertal development. Because programmed DSBs are generated to initiate genetic recombinations involved in the production of sperm and eggs in reproductive organs (a process known as meiosis), meiotic defects and arrest can occur when ATM is not present.[30][31][32] Immune system defects and immune-related cancersAs lymphocytes develop from stem cells in the bone marrow into mature lymphocytes in the periphery, they rearrange special segments of their DNA [V(D)J recombination process]. This process requires them to make DSBs, which are difficult to repair in the absence of ATM.[37][38][39][40] As a result, most people with A–T have reduced numbers of lymphocytes and some impairment of lymphocyte function (such as an impaired ability to make antibodies in response to vaccines or infections). In addition, broken pieces of DNA in chromosomes involved in the above-mentioned rearrangements have a tendency to recombine with other genes (translocation), making the cells prone to the development of cancer (lymphoma and leukemia). Progeric changesCells from people with A–T demonstrate genomic instability, slow growth and premature senescence in culture, shortened telomeres and an ongoing, low-level stress response.[4][41] These factors may contribute to the progeric (signs of early aging) changes of skin and hair sometimes observed in people with A–T. For example, DNA damage and genomic instability cause melanocyte stem cell (MSC) differentiation which produces graying. Thus, ATM may be a “stemness checkpoint” protecting against MSC differentiation and premature graying of the hair.[42] TelangiectasiaThe cause of telangiectasia or dilated blood vessels in the absence of the ATM protein is not yet known. Increased alpha-fetoprotein (AFP) levelsApproximately 95% of people with A–T have elevated serum AFP levels after the age of two, and measured levels of AFP appear to increase slowly over time.[43] AFP levels are very high in the newborn, and normally descend to adult levels over the first year to 18 months. The reason for why individuals with A–T have elevated levels of AFP is not yet known. NeurodegenerationA–T is one of several DNA repair disorders which result in neurological abnormalities or degeneration. Arguably some of the most devastating symptoms of A–T are a result of progressive cerebellar degeneration, characterized by the loss of Purkinje cells and, to a lesser extent, granule cells (located exclusively in the cerebellum).[8] The cause of this cell loss is not known, though many hypotheses have been proposed based on experiments performed both in cell culture and in the mouse model of A–T. Current hypotheses explaining the neurodegeneration associated with A–T include the following:
These hypotheses may not be mutually exclusive and more than one of these mechanisms may underlie neuronal cell death when there is an absence or deficiency of ATM. Further, cerebellar damage and loss of Purkinje and granule cells do not explain all of the neurologic abnormalities seen in people with A–T. The effects of ATM deficiency on the other areas of the brain outside of the cerebellum are being actively investigated. Radiation exposurePeople with A–T have an increased sensitivity to ionizing radiation (X-rays and gamma rays). Therefore, X-ray exposure should be limited to times when it is medically necessary, as exposing an A–T patient to ionizing radiation can damage cells in such a way that the body cannot repair them. The cells can cope normally with other forms of radiation, such as ultraviolet light, so there is no need for special precautions from sunlight exposure. Genetics and information about A–T carriersA–T is caused by mutations in the ATM (ATM serine/threonine kinase or ataxia–telangiectasia mutated) gene, which was cloned in 1995.[3] ATM is located on human chromosome 11 (11q22.3) and is made up of 69 exons spread across 150kb of genomic DNA.[62] The mode of inheritance for A–T is autosomal recessive. Each parent is a carrier, meaning that they have one normal copy of the A–T gene (ATM) and one copy which is mutated. A–T occurs if a child inherits the mutated A–T gene from each parent, so in a family with two carrier parents, there is 1 chance in 4 that a child born to the parents will have the disorder. Prenatal diagnosis (and carrier detection) can be carried out in families if the errors (mutation) in an affected child’s two ATM genes have been identified. The process of getting this done can be complicated and, as it requires time, should be arranged before conception. Looking for mutations in the ATM gene of an unrelated person (for example, the spouse of a known A–T carrier) presents significant challenges. Genes often have variant spellings (polymorphisms) which do not affect function. In a gene as large as ATM, such variant spellings are likely to occur and doctors cannot always predict whether a specific variant will or will not cause disease. Genetic counseling can help family members of an A–T patient understand what can or cannot be tested, and how the test results should be interpreted. Carriers of A–T, such as the parents of a person with A–T, have one mutated copy of the ATM gene and one normal copy. They are generally healthy, but there is an increased risk of breast cancer in women. This finding has been confirmed in a variety of different ways, and is the subject of current research. Standard surveillance (including monthly breast self-exams and mammography at the usual schedule for age) is recommended, unless additional tests are indicated because the individual has other risk factors (e.g., family history of breast cancer). DiagnosisThe diagnosis of A–T is usually suspected by the combination of neurologic clinical features (ataxia, abnormal control of eye movement, and postural instability) with telangiectasia and sometimes increased infections, and confirmed by specific laboratory abnormalities (elevated alpha-fetoprotein levels, increased chromosomal breakage or cell death of white blood cells after exposure to X-rays, absence of ATM protein in white blood cells, or mutations in each of the person’s ATM genes). A variety of laboratory abnormalities occur in most people with A–T, allowing for a tentative diagnosis to be made in the presence of typical clinical features. Not all abnormalities are seen in all patients. These abnormalities include:
The diagnosis can be confirmed in the laboratory by finding an absence or deficiency of the ATM protein in cultured blood cells,[64][65] an absence or deficiency of ATM function (kinase assay), or mutations in both copies of the cell’s ATM gene. These more specialized tests are not always needed, but are particularly helpful if a child’s symptoms are atypical. Differential diagnosisThere are several other disorders with similar symptoms or laboratory features that physicians may consider when diagnosing A–T.[66] The three most common disorders that are sometimes confused with A–T are:
Each of these can be distinguished from A–T by the neurologic exam and clinical history. Cerebral palsy (CP) describes a non-progressive disorder of motor function stemming from malformation or early damage to the brain. CP can manifest in many ways, given the different manner in which brain can be damaged; in common to all forms is the emergence of signs and symptoms of impairment as the child develops. However, milestones that have been accomplished and neurologic functions that have developed do not deteriorate in CP as they often do in children with A–T in the late pre-school years. Most children with ataxia caused by CP do not begin to walk at a normal age, whereas most children with A–T start to walk at a normal age even though they often "wobble" from the start. Pure ataxia is a rare manifestation of early brain damage or malformation, however, and the possibility of an occult genetic disorder of brain should be considered and sought for those in whom ataxia is the chief manif estation of CP. Children with ataxic CP will not manifest the laboratory abnormalities associated with A–T. Cogan occulomotor apraxia is a rare disorder of development. Affected children have difficulty moving their eyes only to a new visual target, so they will turn their head past the target to “drag” the eyes to the new object of interest, then turn the head back. This tendency becomes evident in late infancy and toddler years, and mostly improves with time. This contrasts to the oculomotor difficulties evident in children with A–T, which are not evident in early childhood but emerge over time. Cogan’s oculomotor apraxia is generally an isolated problem, or may be associated with broader developmental delay. Friedreich ataxia (FA) is the most common genetic cause of ataxia in children. Like A–T, FA is a recessive disease, appearing in families without a history of the disorder. FA is caused by mutation in the frataxin gene, most often an expansion of a naturally occurring repetition of the three nucleotide bases GAA from the usual 5–33 repetitions of this trinucleotide sequence to greater than 65 repeats on each chromosome. Most often the ataxia appears between 10 and 15 years of age, and differs from A–T by the absence of telangiectasia and oculomotor apraxia, a normal alpha fetalprotein, and the frequent presence of scoliosis, absent tendon reflexes, and abnormal features on the EKG. Individuals with FA manifest difficulty standing in one place that is much enhanced by closure of the eyes (Romberg sign) that is not so apparent in those with A–T – even though those with A–T may have greater difficulty standing in one place with their eyes open. There are other rare disorders that can be confused with A–T, either because of similar clinical features, a similarity of some laboratory features, or both. These include:
Ataxia–oculomotor apraxia type 1 (AOA1) is an autosomal recessive disorder similar to A–T in manifesting increasing problems with coordination and oculomotor apraxia, often at a similar age to those having A–T. It is caused by mutation in the gene coding for the protein aprataxin. Affected individuals differ from those with A–T by the early appearance of peripheral neuropathy, early in their course manifest difficulty with initiation of gaze shifts, and the absence of ocular telangiectasia, but laboratory features are of key importance in the differentiation of the two. Individuals with AOA1 have a normal AFP, normal measures of immune function, and after 10–15 years have low serum levels of albumin. Genetic testing of the aprataxin gene can confirm the diagnosis. There is no enhanced risk for cancer. Ataxia–oculomotor apraxia type 2 (AOA2) is an autosomal recessive disorder also similar to A–T in manifesting increasing problems with coordination and peripheral neuropathy, but oculomotor apraxia is present in only half of affected individuals. Ocular telangiectasia do not develop. Laboratory abnormalities of AOA2 are like A–T, and unlike AOA1, in having an elevated serum AFP level, but like AOA1 and unlike A–T in having normal markers of immune function. Genetic testing of the senataxin gene (SETX) can confirm the diagnosis. There is no enhanced risk for cancer. Ataxia–telangiectasia like disorder (ATLD) is an extremely rare condition, caused by mutation in the hMre11 gene, that could be considered in the differential diagnosis of A–T. Patients with ATLD are very similar to those with A–T in showing a progressive cerebellar ataxia, hypersensitivity to ionizing radiation and genomic instability. Those rare individuals with ATLD who are well described differ from those with A–T by the absence of telangiectasia, normal immunoglobulin levels, a later onset, and a slower progression of the symptoms. Because of its rarity, it is not yet known whether or not ATLD carries an increased risk to develop cancer. Because those mutations of Mre11 that severely impair the MRE11 protein are incompatible with life, individuals with ATLD all have some partial function of the Mre11 protein, and hence likely all have their own levels of disease severity. Nijmegen breakage syndrome (NBS) is a rare genetic disorder that has similar chromosomal instability to that seen in people with A–T, but the problems experienced are quite different. Children with NBS have significant microcephaly, a distinct facial appearance, short stature, and moderate cognitive impairment, but do not experience any neurologic deterioration over time. Like those with A–T, children with NBS have enhanced sensitivity to radiation, disposition to lymphoma and leukemia, and some laboratory measures of impaired immune function, but do not have ocular telangiectasia or an elevated level of AFP. The proteins expressed by the hMre11 (defective in ATLD) and Nbs1 (defective in NBS) genes exist in the cell as a complex, along with a third protein expressed by the hRad50 gene. This complex, known as the MRN complex, plays an important role in DNA damage repair and signaling and is required to recruit ATM to the sites of DNA double strand breaks. Mre11 and Nbs1 are also targets for phosphorylation by the ATM kinase. Thus, the similarity of the three diseases can be explained in part by the fact that the protein products of the three genes mutated in these disorders interact in common pathways in the cell. Differentiation of these disorders is often possible with clinical features and selected laboratory tests. In cases where the distinction is unclear, clinical laboratories can identify genetic abnormalities of ATM, aprataxin and senataxin, and specialty centers can identify abnormality of the proteins of potentially responsible genes, such as ATM, MRE11, nibrin, TDP1, aprataxin and senataxin as well as other proteins important to ATM function such as ATR, DNA-PK, and RAD50. ManagementAtaxia and other neurologic problemsThere is no treatment known to slow or stop the progression of the neurologic problems. Treatment of A–T is symptomatic and supportive. Physical, occupational and speech therapies and exercise may help maintain function but will not slow the course of neurodegeneration. Therapeutic exercises should not be used to the point of fatigue and should not interfere with activities of daily life. Certain anti-Parkinson and anti-epileptic drugs may be useful in the management of symptoms, but should be prescribed in consultation with a neurologist. Immune problemsAll individuals with A–T should have at least one comprehensive immunologic evaluation that measures the number and type of lymphocytes in the blood (T-lymphocytes and B-lymphocytes), the levels of serum immunoglobulins (IgG, IgA, and IgM) and antibody responses to T-dependent (e.g., tetanus, Hemophilus influenzae b) and T-independent (23-valent pneumococcal polysaccharide) vaccines. For the most part, the pattern of immunodeficiency seen in an A–T patient early in life (by age five) will be the same pattern seen throughout the lifetime of that individual. Therefore, the tests need not be repeated unless that individual develops more problems with infection. Problems with immunity sometimes can be overcome by immunization. Vaccines against common bacterial respiratory pathogens such as Hemophilus influenzae, pneumococci and influenza virus (the “flu”) are commercially available and often help to boost antibody responses, even in individuals with low immunoglobulin levels. If the vaccines do not work and the patient continues to have problems with infections, gamma globulin therapy (IV or subcutaneous infusions of antibodies collected from normal individuals) may be of benefit. A small number of people with A–T develop an abnormality in which one or more types of immunoglobulin are increased far beyond the normal range. In a few cases, the immunoglobulin levels can be increased so much that the blood becomes thick and does not flow properly. Therapy for this problem must be tailored to the specific abnormality found and its severity. If an individual patient’s susceptibility to infection increases, it is important to reassess immune function in case deterioration has occurred and a new therapy is indicated. If infections are occurring in the lung, it is also important to investigate the possibility of dysfunctional swallow with aspiration into the lungs (see above sections under Symptoms: Lung Disease and Symptoms: Feeding, Swallowing and Nutrition.) Most people with A–T have low lymphocyte counts in the blood. This problem seems to be relatively stable with age, but a rare number of people do have progressively decreasing lymphocyte counts as they get older. In the general population, very low lymphocyte counts are associated with an increased risk for infection. Such individuals develop complications from live viral vaccines (measles, mumps, rubella and chickenpox), chronic or severe viral infections, yeast infections of the skin and vagina, and opportunistic infections (such as pneumocystis pneumonia). Although lymphocyte counts are often as low in people with A–T, they seldom have problems with opportunistic infections. (The one exception to that rule is that problems with chronic or recurrent warts are common.) The number and function of T-lymphocytes should be re-evaluated if a person with A–T is treated with corticosteroid drugs such as prednisone for longer than a few weeks or is treated with chemotherapy for cancer. If lymphocyte counts are low in people taking those types of drugs, the use of prophylactic antibiotics is recommended to prevent opportunistic infections. If the tests show significant abnormalities of the immune system, a specialist in immunodeficiency or infectious diseases will be able to discuss various treatment options. Absence of immunoglobulin or antibody responses to vaccine can be treated with replacement gamma globulin infusions, or can be managed with prophylactic antibiotics and minimized exposure to infection. If antibody function is normal, all routine childhood immunizations including live viral vaccines (measles, mumps, rubella and varicella) should be given. In addition, several “special” vaccines (that is, licensed but not routine for otherwise healthy children and young adults) should be given to decrease the risk that an A–T patient will develop lung infections. The patient and all household members should receive the influenza (flu) vaccine every fall. People with A–T who are less than two years old should receive three (3) doses of a pneumococcal conjugate vaccine (Prevnar) given at two month intervals. People older than two years who have not previously been immunized with Prevnar should receive two (2) doses of Prevnar. At least 6 months after the last Prevnar has been given and after the child is at least two years old, the 23-valent pneumococcal vaccine should be administered. Immunization with the 23-valent pneumococcal vaccine should be repeated approximately every five years after the first dose. In people with A–T who have low levels of IgA, further testing should be performed to determine whether the IgA level is low or completely absent. If absent, there is a slightly increased risk of a transfusion reaction. “Medical Alert” bracelets are not necessary, but the family and primary physician should be aware that if there is elective surgery requiring red cell transfusion, the cells should be washed to decrease the risk of an allergic reaction. People with A–T also have an increased risk of developing autoimmune or chronic inflammatory diseases. This risk is probably a secondary effect of their immunodeficiency and not a direct effect of the lack of ATM protein. The most common examples of such disorders in A–T include immune thrombocytopenia (ITP), several forms of arthritis, and vitiligo. Lung diseaseRecurrent sinus and lung infections can lead to the development of chronic lung disease.[18] Such infections should be treated with appropriate antibiotics to prevent and limit lung injury. Administration of antibiotics should be considered when children and adults have prolonged respiratory symptoms (greater than 7 days), even following what was presumed to have been a viral infection. To help prevent respiratory illnesses from common respiratory pathogens, annual influenza vaccinations should be given and pneumococcal vaccines should be administered when appropriate. Antibiotic treatment should also be considered in children with chronic coughs that are productive of mucous, those who do not respond to aggressive pulmonary clearance techniques and in children with muco-purulent secretions from the sinuses or chest. A wet cough can also be associated with chronic aspiration which should be ruled out through proper diagnostic studies, however aspiration and respiratory infections are not necessarily exclusive of each other. In children and adults with bronchiectasis, chronic antibiotic therapy should be considered to slow chronic lung disease progression. Culturing of the sinuses may be needed to direct antibiotic therapy. This can be done by an Ear Nose and Throat (ENT) specialist. In addition, diagnostic bronchoscopy may be necessary in people who have recurrent pneumonias, especially those who do not respond or respond incompletely to a course of antibiotics. Clearance of bronchial secretions is essential for good pulmonary health and can help limit injury from acute and chronic lung infections. Children and adults with increased bronchial secretions can benefit from routine chest therapy using the manual method, an a cappella device or a chest physiotherapy vest. Chest physiotherapy can help bring up mucous from the lower bronchial tree, however an adequate cough is needed to remove secretions. In people who have decreased lung reserve and a weak cough, use of an insufflator-exsufflator (cough-assist) device may be useful as a maintenance therapy or during acute respiratory illnesses to help remove bronchial secretions from the upper airways. Evaluation by a Pulmonology specialist however, should first be done to properly assess patient suitability. Children and adults with chronic dry cough, increased work of breathing (fast respiratory rate, shortness of breath at rest or with activities) and absence of an infectious process to explain respiratory symptoms should be evaluated for interstitial lung disease or another intrapulmonary process. Evaluation by a Pulmonologist and a CT scan of the chest should be considered in individuals with symptoms of interstitial lung disease or to rule other non-infectious pulmonary processes. People diagnosed with interstitial lung disease may benefit from systemic steroids. Feeding, swallowing and nutritionOral intake may be aided by teaching persons with A–T how to drink, chew and swallow more safely. The propriety of treatments for swallowing problems should be determined following evaluation by an expert in the field of speech-language pathology. Dieticians may help treat nutrition problems by recommending dietary modifications, including high calorie foods or food supplements. A feeding (gastrostomy) tube is recommended when any of the following occur:[67]
Feeding tubes can decrease the risk of aspiration by enabling persons to avoid liquids or foods that are difficult to swallow and provide adequate calories without the stress and time commitment of prolonged meals. Gastrostomy tubes do not prevent people from eating by mouth. Once a tube is in place, the general goal should be to maintain weight at the 10–25th percentile. Education and socializationMost children with A–T have difficulty in school because of a delay in response time to visual, verbal or other cues, slurred and quiet speech (dysarthria), abnormalities of eye control (oculomotor apraxia), and impaired fine motor control. Despite these problems, children with A–T often enjoy school if proper accommodations to their disability can be made. The decision about the need for special education classes or extra help in regular classes is highly influenced by the local resources available. Decisions about proper educational placement should be revisited as often as circumstances warrant. Despite their many neurologic impairments, most individuals with A–T are very socially aware and socially skilled, and thus benefit from sustained peer relationships developed at school. Some individuals are able to function quite well despite their disabilities and a few have graduated from community colleges. Many of the problems encountered will benefit from special attention, as problems are often related more to “input and output” issues than to intellectual impairment. Problems with eye movement control make it difficult for people with A–T to read, yet most fully understand the meaning and nuances of text that is read to them. Delays in speech initiation and lack of facial expression make it seem that they do not know the answers to questions. Reduction of the skilled effort needed to answer questions, and an increase of the time available to respond, is often rewarded by real accomplishment. It is important to recognize that intellectual disability is not regularly a part of the clinical picture of A–T although school performance may be suboptimal because of the many difficulties in reading, writing, and speech. Children with A–T are often very conscious of their appearance, and strive to appear normal to their peers and teachers. Life within the ataxic body can be tiring. The enhanced effort needed to maintain appearances and increased energy expended in abnormal tone and extra movements all contribute to physical and mental fatigue. As a consequence, for some a shortened school day yields real benefits. General recommendations
Clinics and supportThe US, UK, Australia, Israel, The Netherlands, Germany, Poland, Norway and Japan have specialized clinics for patients with A–T. These clinics house multidisciplinary medical teams, including neurologists, immunologists, pulmonologists and therapists, capable of dealing with the many facets of this disease. EpidemiologyIndividuals of all races and ethnicities are affected equally. The incidence worldwide is estimated to be between 1 in 40,000 and 1 in 100,000 people.[4][6] PrognosisThe life expectancy of people with A–T is highly variable. The average is approximately 25 years, but continues to improve with advances in care. The two most common causes of death are chronic lung disease (about one-third of cases) and cancer (about one-third of cases). Research directionsAn open-label Phase II clinical trial studying the use of red blood cells (erythrocytes) loaded with dexamethasone sodium phosphate found that this treatment improved symptoms and appeared to be well tolerated.[68] This treatment uses a unique delivery system for medication by using the patient's own red blood cells as the delivery vehicle for the drug.[69] Given the other immunologic deficits present in individuals with A–T, there remains a need to evaluate the therapeutic potential of steroids further, particularly with respect to the duration of any benefit and its long-term safety. References1. ^{{cite journal | vauthors = Louis-Bar D | year = 1941 | title = Sur un syndrome progressif cormprenant des télangiectasies capillaires cutanées et conjonctivales symétriques, à disposition naevoïde et des troubles cérébelleux | url = | journal = Confinia Neurologica | volume = 4 | issue = 1–2| pages = 32–42 | doi = 10.1159/000106149 }} 2. ^{{cite journal | vauthors = Boder E | title = Ataxia–telangiectasia: an overview | journal = Kroc Foundation Series | volume = 19 | pages = 1–63 | year = 1985 | pmid = 2415689 }} 3. ^1 2 {{cite journal | vauthors = Savitsky K, Bar-Shira A, Gilad S, Rotman G, Ziv Y, Vanagaite L, Tagle DA, Smith S, Uziel T, Sfez S, Ashkenazi M, Pecker I, Frydman M, Harnik R, Patanjali SR, Simmons A, Clines GA, Sartiel A, Gatti RA, Chessa L, Sanal O, Lavin MF, Jaspers NG, Taylor AM, Arlett CF, Miki T, Weissman SM, Lovett M, Collins FS, Shiloh Y | title = A single ataxia telangiectasia gene with a product similar to PI-3 kinase | journal = Science | volume = 268 | issue = 5218 | pages = 1749–53 | date = June 1995 | pmid = 7792600 | doi = 10.1126/science.7792600 }} 4. ^1 2 {{cite journal | vauthors = Shiloh Y, Kastan MB | title = ATM: genome stability, neuronal development, and cancer cross paths | journal = Advances in Cancer Research | volume = 83 | pages = 209–54 | year = 2001 | pmid = 11665719 | doi = 10.1016/s0065-230x(01)83007-4 | isbn = 9780120066834 }} 5. ^{{Cite web |url= https://ghr.nlm.nih.gov/condition/ataxia-telangiectasia |title=Ataxia–telangiectasia | work =Genetics Home Reference|language=en|access-date=2018-03-29}} 6. ^1 {{cite journal | vauthors = Swift M, Morrell D, Cromartie E, Chamberlin AR, Skolnick MH, Bishop DT | title = The incidence and gene frequency of ataxia–telangiectasia in the United States | journal = American Journal of Human Genetics | volume = 39 | issue = 5 | pages = 573–83 | date = November 1986 | pmid = 3788973 | pmc = 1684065 }} 7. ^{{cite journal | vauthors = Cabana MD, Crawford TO, Winkelstein JA, Christensen JR, Lederman HM | title = Consequences of the delayed diagnosis of ataxia–telangiectasia | journal = Pediatrics | volume = 102 | issue = 1 Pt 1 | pages = 98–100 | date = July 1998 | pmid = 9651420 | doi = 10.1542/peds.102.1.98 }} 8. ^1 {{cite journal | vauthors = Crawford TO | title = Ataxia telangiectasia | journal = Seminars in Pediatric Neurology | volume = 5 | issue = 4 | pages = 287–94 | date = December 1998 | pmid = 9874856 | doi = 10.1016/s1071-9091(98)80007-7 }} 9. ^{{cite journal | vauthors = Crawford TO, Mandir AS, Lefton-Greif MA, Goodman SN, Goodman BK, Sengul H, Lederman HM | title = Quantitative neurologic assessment of ataxia–telangiectasia | journal = Neurology | volume = 54 | issue = 7 | pages = 1505–9 | date = April 2000 | pmid = 10751267 | doi = 10.1212/wnl.54.7.1505 }} 10. ^{{cite journal | vauthors = Cabana MD, Crawford TO, Winkelstein JA, Christensen JR, Lederman HM | title = Consequences of the delayed diagnosis of ataxia–telangiectasia | journal = Pediatrics | volume = 102 | issue = 1 Pt 1 | pages = 98–100 | date = July 1998 | pmid = 9651420 | doi = 10.1542/peds.102.1.98 }} 11. ^{{cite journal | vauthors = Lavin MF, Gueven N, Bottle S, Gatti RA | title = Current and potential therapeutic strategies for the treatment of ataxia–telangiectasia | journal = British Medical Bulletin | volume = 81–82 | pages = 129–47 | date = 2007 | pmid = 17586848 | doi = 10.1093/bmb/ldm012 }} 12. ^{{cite journal | vauthors = Lin DD, Barker PB, Lederman HM, Crawford TO | title = Cerebral abnormalities in adults with ataxia–telangiectasia | journal = AJNR. American Journal of Neuroradiology | volume = 35 | issue = 1 | pages = 119–23 | date = January 2014 | pmid = 23886747 | pmc = 4106125 | doi = 10.3174/ajnr.A3646 }} 13. ^{{cite journal | vauthors = Nowak-Wegrzyn A, Crawford TO, Winkelstein JA, Carson KA, Lederman HM | title = Immunodeficiency and infections in ataxia–telangiectasia | journal = The Journal of Pediatrics | volume = 144 | issue = 4 | pages = 505–11 | date = April 2004 | pmid = 15069401 | doi = 10.1016/j.jpeds.2003.12.046 }} 14. ^{{cite journal | vauthors = Reiman A, Srinivasan V, Barone G, Last JI, Wootton LL, Davies EG, Verhagen MM, Willemsen MA, Weemaes CM, Byrd PJ, Izatt L, Easton DF, Thompson DJ, Taylor AM | title = Lymphoid tumours and breast cancer in ataxia telangiectasia; substantial protective effect of residual ATM kinase activity against childhood tumours | journal = British Journal of Cancer | volume = 105 | issue = 4 | pages = 586–91 | date = August 2011 | pmid = 21792198 | pmc = 3170966 | doi = 10.1038/bjc.2011.266 }} 15. ^{{cite journal | vauthors = Thompson D, Duedal S, Kirner J, McGuffog L, Last J, Reiman A, Byrd P, Taylor M, Easton DF | title = Cancer risks and mortality in heterozygous ATM mutation carriers | journal = Journal of the National Cancer Institute | volume = 97 | issue = 11 | pages = 813–22 | date = June 2005 | pmid = 15928302 | doi = 10.1093/jnci/dji141 }} 16. ^{{cite journal | vauthors = Renwick A, Thompson D, Seal S, Kelly P, Chagtai T, Ahmed M, North B, Jayatilake H, Barfoot R, Spanova K, McGuffog L, Evans DG, Eccles D, Easton DF, Stratton MR, Rahman N | title = ATM mutations that cause ataxia–telangiectasia are breast cancer susceptibility alleles | journal = Nature Genetics | volume = 38 | issue = 8 | pages = 873–5 | date = August 2006 | pmid = 16832357 | doi = 10.1038/ng1837 | collaboration = Breast Cancer Susceptibility Collaboration, (UK) }} 17. ^{{cite journal | vauthors = Paller AS, Massey RB, Curtis MA, Pelachyk JM, Dombrowski HC, Leickly FE, Swift M | title = Cutaneous granulomatous lesions in patients with ataxia–telangiectasia | journal = The Journal of Pediatrics | volume = 119 | issue = 6 | pages = 917–22 | date = December 1991 | pmid = 1960607 | doi = 10.1016/s0022-3476(05)83043-4 }} 18. ^1 {{cite journal | vauthors = McGrath-Morrow SA, Gower WA, Rothblum-Oviatt C, Brody AS, Langston C, Fan LL, Lefton-Greif MA, Crawford TO, Troche M, Sandlund JT, Auwaerter PG, Easley B, Loughlin GM, Carroll JL, Lederman HM | title = Evaluation and management of pulmonary disease in ataxia–telangiectasia | journal = Pediatric Pulmonology | volume = 45 | issue = 9 | pages = 847–59 | date = September 2010 | pmid = 20583220 | pmc = 4151879 | doi = 10.1002/ppul.21277 }} 19. ^{{cite journal | vauthors = Lefton-Greif MA, Crawford TO, Winkelstein JA, Loughlin GM, Koerner CB, Zahurak M, Lederman HM | title = Oropharyngeal dysphagia and aspiration in patients with ataxia–telangiectasia | journal = The Journal of Pediatrics | volume = 136 | issue = 2 | pages = 225–31 | date = February 2000 | pmid = 10657830 | doi = 10.1016/s0022-3476(00)70106-5 }} 20. ^{{cite journal | vauthors = Farr AK, Shalev B, Crawford TO, Lederman HM, Winkelstein JA, Repka MX | title = Ocular manifestations of ataxia–telangiectasia | journal = American Journal of Ophthalmology | volume = 134 | issue = 6 | pages = 891–6 | date = December 2002 | pmid = 12470759 | doi = 10.1016/s0002-9394(02)01796-8 }} 21. ^1 {{cite journal | vauthors = Derheimer FA, Kastan MB | title = Multiple roles of ATM in monitoring and maintaining DNA integrity | journal = FEBS Letters | volume = 584 | issue = 17 | pages = 3675–81 | date = September 2010 | pmid = 20580718 | pmc = 2950315 | doi = 10.1016/j.febslet.2010.05.031 }} 22. ^1 {{cite journal | vauthors = Kurz EU, Lees-Miller SP | title = DNA damage-induced activation of ATM and ATM-dependent signaling pathways | journal = DNA Repair | volume = 3 | issue = 8–9 | pages = 889–900 | date = Aug–Sep 2004 | pmid = 15279774 | doi = 10.1016/j.dnarep.2004.03.029 }} 23. ^1 {{cite journal | vauthors = Dar I, Biton S, Shiloh Y, Barzilai A | title = Analysis of the ataxia telangiectasia mutated-mediated DNA damage response in murine cerebellar neurons | journal = The Journal of Neuroscience | volume = 26 | issue = 29 | pages = 7767–74 | date = July 2006 | pmid = 16855104 | doi = 10.1523/JNEUROSCI.2055-06.2006 }} 24. ^{{cite journal | vauthors = Gorodetsky E, Calkins S, Ahn J, Brooks PJ | title = ATM, the Mre11/Rad50/Nbs1 complex, and topoisomerase I are concentrated in the nucleus of Purkinje neurons in the juvenile human brain | journal = DNA Repair | volume = 6 | issue = 11 | pages = 1698–707 | date = November 2007 | pmid = 17706468 | pmc = 2797317 | doi = 10.1016/j.dnarep.2007.06.011 }} 25. ^1 {{cite journal | vauthors = Valentin-Vega YA, Maclean KH, Tait-Mulder J, Milasta S, Steeves M, Dorsey FC, Cleveland JL, Green DR, Kastan MB | title = Mitochondrial dysfunction in ataxia–telangiectasia | journal = Blood | volume = 119 | issue = 6 | pages = 1490–500 | date = February 2012 | pmid = 22144182 | pmc = 3286212 | doi = 10.1182/blood-2011-08-373639 }} 26. ^1 {{cite journal | vauthors = Guo Z, Kozlov S, Lavin MF, Person MD, Paull TT | title = ATM activation by oxidative stress | journal = Science | volume = 330 | issue = 6003 | pages = 517–21 | date = October 2010 | pmid = 20966255 | doi = 10.1126/science.1192912 | hdl = 2152/9689 }} 27. ^{{cite journal | vauthors = Bakkenist CJ, Kastan MB | title = DNA damage activates ATM through intermolecular autophosphorylation and dimer dissociation | journal = Nature | volume = 421 | issue = 6922 | pages = 499–506 | date = January 2003 | pmid = 12556884 | doi = 10.1038/nature01368 }} 28. ^{{cite journal | vauthors = Kanu N, Behrens A | title = ATMINistrating ATM signalling: regulation of ATM by ATMIN | journal = Cell Cycle | volume = 7 | issue = 22 | pages = 3483–6 | date = November 2008 | pmid = 19001856 | doi = 10.4161/cc.7.22.7044 }} 29. ^{{cite journal | vauthors = Shiloh Y | title = ATM and related protein kinases: safeguarding genome integrity | journal = Nature Reviews. Cancer | volume = 3 | issue = 3 | pages = 155–68 | date = March 2003 | pmid = 12612651 | doi = 10.1038/nrc1011 }} 30. ^1 {{cite journal | vauthors = Barlow C, Hirotsune S, Paylor R, Liyanage M, Eckhaus M, Collins F, Shiloh Y, Crawley JN, Ried T, Tagle D, Wynshaw-Boris A | title = Atm-deficient mice: a paradigm of ataxia telangiectasia | journal = Cell | volume = 86 | issue = 1 | pages = 159–71 | date = July 1996 | pmid = 8689683 | doi = 10.1016/S0092-8674(00)80086-0 }} 31. ^{{cite journal | vauthors = Plug AW, Peters AH, Xu Y, Keegan KS, Hoekstra MF, Baltimore D, de Boer P, Ashley T | title = ATM and RPA in meiotic chromosome synapsis and recombination | journal = Nature Genetics | volume = 17 | issue = 4 | pages = 457–61 | date = December 1997 | pmid = 9398850 | doi = 10.1038/ng1297-457 }} 32. ^{{cite journal | vauthors = Barchi M, Roig I, Di Giacomo M, de Rooij DG, Keeney S, Jasin M | title = ATM promotes the obligate XY crossover and both crossover control and chromosome axis integrity on autosomes | journal = PLoS Genetics | volume = 4 | issue = 5 | pages = e1000076 | date = May 2008 | pmid = 18497861 | pmc = 2374915 | doi = 10.1371/journal.pgen.1000076 }} {{open access}} 33. ^{{cite journal | vauthors = Lumsden JM, McCarty T, Petiniot LK, Shen R, Barlow C, Wynn TA, Morse HC, Gearhart PJ, Wynshaw-Boris A, Max EE, Hodes RJ | title = Immunoglobulin class switch recombination is impaired in Atm-deficient mice | journal = The Journal of Experimental Medicine | volume = 200 | issue = 9 | pages = 1111–21 | date = November 2004 | pmid = 15504820 | pmc = 2211853 | doi = 10.1084/jem.20041074 }} 34. ^{{cite journal | vauthors = Franco S, Alt FW, Manis JP | title = Pathways that suppress programmed DNA breaks from progressing to chromosomal breaks and translocations | journal = DNA Repair | volume = 5 | issue = 9–10 | pages = 1030–41 | date = September 2006 | pmid = 16934538 | doi = 10.1016/j.dnarep.2006.05.024 }} 35. ^{{cite journal | vauthors = Callén E, Jankovic M, Wong N, Zha S, Chen HT, Difilippantonio S, Di Virgilio M, Heidkamp G, Alt FW, Nussenzweig A, Nussenzweig M | title = Essential role for DNA-PKcs in DNA double-strand break repair and apoptosis in ATM-deficient lymphocytes | journal = Molecular Cell | volume = 34 | issue = 3 | pages = 285–97 | date = May 2009 | pmid = 19450527 | pmc = 2709792 | doi = 10.1016/j.molcel.2009.04.025 }} 36. ^{{cite journal | vauthors = Bagley J, Singh G, Iacomini J | title = Regulation of oxidative stress responses by ataxia–telangiectasia mutated is required for T cell proliferation | journal = Journal of Immunology | volume = 178 | issue = 8 | pages = 4757–63 | date = April 2007 | pmid = 17404255 | doi = 10.4049/jimmunol.178.8.4757 }} 37. ^{{cite journal | vauthors = Bredemeyer AL, Sharma GG, Huang CY, Helmink BA, Walker LM, Khor KC, Nuskey B, Sullivan KE, Pandita TK, Bassing CH, Sleckman BP | title = ATM stabilizes DNA double-strand-break complexes during V(D)J recombination | journal = Nature | volume = 442 | issue = 7101 | pages = 466–70 | date = July 2006 | pmid = 16799570 | doi = 10.1038/nature04866 }} 38. ^{{cite journal | vauthors = Bredemeyer AL, Huang CY, Walker LM, Bassing CH, Sleckman BP | title = Aberrant V(D)J recombination in ataxia telangiectasia mutated-deficient lymphocytes is dependent on nonhomologous DNA end joining | journal = Journal of Immunology | volume = 181 | issue = 4 | pages = 2620–5 | date = August 2008 | pmid = 18684952 | pmc = 3598579 | doi = 10.4049/jimmunol.181.4.2620 }} 39. ^{{cite journal | vauthors = Bredemeyer AL, Helmink BA, Innes CL, Calderon B, McGinnis LM, Mahowald GK, Gapud EJ, Walker LM, Collins JB, Weaver BK, Mandik-Nayak L, Schreiber RD, Allen PM, May MJ, Paules RS, Bassing CH, Sleckman BP | title = DNA double-strand breaks activate a multi-functional genetic program in developing lymphocytes | journal = Nature | volume = 456 | issue = 7223 | pages = 819–23 | date = December 2008 | pmid = 18849970 | pmc = 2605662 | doi = 10.1038/nature07392 }} 40. ^{{cite journal | vauthors = Callén E, Jankovic M, Difilippantonio S, Daniel JA, Chen HT, Celeste A, Pellegrini M, McBride K, Wangsa D, Bredemeyer AL, Sleckman BP, Ried T, Nussenzweig M, Nussenzweig A | title = ATM prevents the persistence and propagation of chromosome breaks in lymphocytes | journal = Cell | volume = 130 | issue = 1 | pages = 63–75 | date = July 2007 | pmid = 17599403 | doi = 10.1016/j.cell.2007.06.016 }} 41. ^{{cite journal | vauthors = Shiloh Y, Tabor E, Becker Y | title = Colony-forming ability of ataxia–telangiectasia skin fibroblasts is an indicator of their early senescence and increased demand for growth factors | journal = Experimental Cell Research | volume = 140 | issue = 1 | pages = 191–9 | date = July 1982 | pmid = 6213420 | doi = 10.1016/0014-4827(82)90169-0 }} 42. ^{{cite journal | vauthors = Inomata K, Aoto T, Binh NT, Okamoto N, Tanimura S, Wakayama T, Iseki S, Hara E, Masunaga T, Shimizu H, Nishimura EK | title = Genotoxic stress abrogates renewal of melanocyte stem cells by triggering their differentiation | journal = Cell | volume = 137 | issue = 6 | pages = 1088–99 | date = June 2009 | pmid = 19524511 | doi = 10.1016/j.cell.2009.03.037 }} 43. ^{{cite journal | vauthors = Stray-Pedersen A, Borresen-Dale AL, Paus E, Lindman CR, Burgers T, Abrahamsen TG | title = Alpha fetoprotein is increasing with age in ataxia–telangiectasia | journal = European Journal of Paediatric Neurology | volume = 11 | issue = 6 | pages = 375–80 | date = November 2007 | pmid = 17540590 | doi = 10.1016/j.ejpn.2007.04.001 }} 44. ^{{cite journal | vauthors = Biton S, Dar I, Mittelman L, Pereg Y, Barzilai A, Shiloh Y | title = Nuclear ataxia–telangiectasia mutated (ATM) mediates the cellular response to DNA double strand breaks in human neuron-like cells | journal = The Journal of Biological Chemistry | volume = 281 | issue = 25 | pages = 17482–91 | date = June 2006 | pmid = 16627474 | doi = 10.1074/jbc.M601895200 }} 45. ^{{cite journal | vauthors = Herzog KH, Chong MJ, Kapsetaki M, Morgan JI, McKinnon PJ | title = Requirement for Atm in ionizing radiation-induced cell death in the developing central nervous system | journal = Science | volume = 280 | issue = 5366 | pages = 1089–91 | date = May 1998 | pmid = 9582124 | doi = 10.1126/science.280.5366.1089 }} 46. ^{{cite journal | vauthors = Lee Y, Chong MJ, McKinnon PJ | title = Ataxia telangiectasia mutated-dependent apoptosis after genotoxic stress in the developing nervous system is determined by cellular differentiation status | journal = The Journal of Neuroscience | volume = 21 | issue = 17 | pages = 6687–93 | date = September 2001 | pmid = 11517258 | doi = 10.1523/JNEUROSCI.21-17-06687.2001 }} 47. ^{{cite journal | vauthors = Sordet O, Redon CE, Guirouilh-Barbat J, Smith S, Solier S, Douarre C, Conti C, Nakamura AJ, Das BB, Nicolas E, Kohn KW, Bonner WM, Pommier Y | title = Ataxia telangiectasia mutated activation by transcription- and topoisomerase I-induced DNA double-strand breaks | journal = EMBO Reports | volume = 10 | issue = 8 | pages = 887–93 | date = August 2009 | pmid = 19557000 | pmc = 2726680 | doi = 10.1038/embor.2009.97 }} 48. ^{{cite journal | vauthors = Das BB, Antony S, Gupta S, Dexheimer TS, Redon CE, Garfield S, Shiloh Y, Pommier Y | title = Optimal function of the DNA repair enzyme TDP1 requires its phosphorylation by ATM and/or DNA-PK | journal = The EMBO Journal | volume = 28 | issue = 23 | pages = 3667–80 | date = December 2009 | pmid = 19851285 | pmc = 2790489 | doi = 10.1038/emboj.2009.302 }} 49. ^{{cite journal | vauthors = Iourov IY, Vorsanova SG, Liehr T, Kolotii AD, Yurov YB | title = Increased chromosome instability dramatically disrupts neural genome integrity and mediates cerebellar degeneration in the ataxia–telangiectasia brain | journal = Human Molecular Genetics | volume = 18 | issue = 14 | pages = 2656–69 | date = July 2009 | pmid = 19414482 | doi = 10.1093/hmg/ddp207 }} 50. ^{{cite journal | vauthors = Alexander A, Cai SL, Kim J, Nanez A, Sahin M, MacLean KH, Inoki K, Guan KL, Shen J, Person MD, Kusewitt D, Mills GB, Kastan MB, Walker CL | title = ATM signals to TSC2 in the cytoplasm to regulate mTORC1 in response to ROS | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 107 | issue = 9 | pages = 4153–8 | date = March 2010 | pmid = 20160076 | pmc = 2840158 | doi = 10.1073/pnas.0913860107 }} 51. ^{{cite journal | vauthors = Cosentino C, Grieco D, Costanzo V | title = ATM activates the pentose phosphate pathway promoting anti-oxidant defence and DNA repair | journal = The EMBO Journal | volume = 30 | issue = 3 | pages = 546–55 | date = February 2011 | pmid = 21157431 | pmc = 3034007 | doi = 10.1038/emboj.2010.330 }} 52. ^{{cite journal | vauthors = Biton S, Barzilai A, Shiloh Y | title = The neurological phenotype of ataxia–telangiectasia: solving a persistent puzzle | journal = DNA Repair | volume = 7 | issue = 7 | pages = 1028–38 | date = July 2008 | pmid = 18456574 | doi = 10.1016/j.dnarep.2008.03.006 }} 53. ^{{cite journal | vauthors = D'Souza AD, Parish IA, Krause DS, Kaech SM, Shadel GS | title = Reducing mitochondrial ROS improves disease-related pathology in a mouse model of ataxia–telangiectasia | journal = Molecular Therapy | volume = 21 | issue = 1 | pages = 42–8 | date = January 2013 | pmid = 23011031 | pmc = 3538311 | doi = 10.1038/mt.2012.203 }} 54. ^{{cite journal | vauthors = Sharma NK, Lebedeva M, Thomas T, Kovalenko OA, Stumpf JD, Shadel GS, Santos JH | title = Intrinsic mitochondrial DNA repair defects in Ataxia Telangiectasia | journal = DNA Repair | volume = 13 | pages = 22–31 | date = January 2014 | pmid = 24342190 | pmc = 6211587 | doi = 10.1016/j.dnarep.2013.11.002 }} 55. ^{{cite journal | vauthors = Yang Y, Herrup K | title = Loss of neuronal cell cycle control in ataxia–telangiectasia: a unified disease mechanism | journal = The Journal of Neuroscience | volume = 25 | issue = 10 | pages = 2522–9 | date = March 2005 | pmid = 15758161 | doi = 10.1523/JNEUROSCI.4946-04.2005 }} 56. ^{{cite journal | vauthors = Li J, Han YR, Plummer MR, Herrup K | title = Cytoplasmic ATM in neurons modulates synaptic function | journal = Current Biology | volume = 19 | issue = 24 | pages = 2091–6 | date = December 2009 | pmid = 19962314 | pmc = 2805770 | doi = 10.1016/j.cub.2009.10.039 }} 57. ^{{cite journal | vauthors = Li J, Chen J, Ricupero CL, Hart RP, Schwartz MS, Kusnecov A, Herrup K | title = Nuclear accumulation of HDAC4 in ATM deficiency promotes neurodegeneration in ataxia telangiectasia | journal = Nature Medicine | volume = 18 | issue = 5 | pages = 783–90 | date = May 2012 | pmid = 22466704 | pmc = 3378917 | doi = 10.1038/nm.2709 }} 58. ^{{cite journal | vauthors = Herrup K | title = ATM and the epigenetics of the neuronal genome | journal = Mechanisms of Ageing and Development | volume = 134 | issue = 10 | pages = 434–9 | date = October 2013 | pmid = 23707635 | pmc = 3791148 | doi = 10.1016/j.mad.2013.05.005 }} 59. ^{{cite journal | vauthors = Li J, Hart RP, Mallimo EM, Swerdel MR, Kusnecov AW, Herrup K | title = EZH2-mediated H3K27 trimethylation mediates neurodegeneration in ataxia–telangiectasia | journal = Nature Neuroscience | volume = 16 | issue = 12 | pages = 1745–53 | date = December 2013 | pmid = 24162653 | pmc = 3965909 | doi = 10.1038/nn.3564 }} 60. ^{{cite journal | vauthors = Jiang D, Zhang Y, Hart RP, Chen J, Herrup K, Li J | title = Alteration in 5-hydroxymethylcytosine-mediated epigenetic regulation leads to Purkinje cell vulnerability in ATM deficiency | journal = Brain | volume = 138 | issue = Pt 12 | pages = 3520–36 | date = December 2015 | pmid = 26510954 | pmc = 4668921 | doi = 10.1093/brain/awv284 }} 61. ^{{cite journal | vauthors = Wood LM, Sankar S, Reed RE, Haas AL, Liu LF, McKinnon P, Desai SD | title = A novel role for ATM in regulating proteasome-mediated protein degradation through suppression of the ISG15 conjugation pathway | journal = PLOS One | volume = 6 | issue = 1 | pages = e16422 | date = January 2011 | pmid = 21298066 | pmc = 3027683 | doi = 10.1371/journal.pone.0016422 }} 62. ^{{cite journal | vauthors = Gatti RA, Berkel I, Boder E, Braedt G, Charmley P, Concannon P, Ersoy F, Foroud T, Jaspers NG, Lange K | title = Localization of an ataxia–telangiectasia gene to chromosome 11q22-23 | journal = Nature | volume = 336 | issue = 6199 | pages = 577–80 | date = December 1988 | pmid = 3200306 | doi = 10.1038/336577a0 }} 63. ^{{cite journal | vauthors = Sun X, Becker-Catania SG, Chun HH, Hwang MJ, Huo Y, Wang Z, Mitui M, Sanal O, Chessa L, Crandall B, Gatti RA | title = Early diagnosis of ataxia–telangiectasia using radiosensitivity testing | journal = The Journal of Pediatrics | volume = 140 | issue = 6 | pages = 724–31 | date = June 2002 | pmid = 12072877 | doi = 10.1067/mpd.2002.123879 }} 64. ^{{cite journal | vauthors = Chun HH, Sun X, Nahas SA, Teraoka S, Lai CH, Concannon P, Gatti RA | title = Improved diagnostic testing for ataxia–telangiectasia by immunoblotting of nuclear lysates for ATM protein expression | journal = Molecular Genetics and Metabolism | volume = 80 | issue = 4 | pages = 437–43 | date = December 2003 | pmid = 14654357 | doi = 10.1016/j.ymgme.2003.09.008 }} 65. ^{{cite journal | vauthors = Taylor AM, Byrd PJ | title = Molecular pathology of ataxia telangiectasia | journal = Journal of Clinical Pathology | volume = 58 | issue = 10 | pages = 1009–15 | date = October 2005 | pmid = 16189143 | pmc = 1770730 | doi = 10.1136/jcp.2005.026062 }} 66. ^{{cite journal | vauthors = Anheim M, Tranchant C, Koenig M | title = The autosomal recessive cerebellar ataxias | journal = The New England Journal of Medicine | volume = 366 | issue = 7 | pages = 636–46 | date = February 2012 | pmid = 22335741 | doi = 10.1056/NEJMra1006610 }} 67. ^{{cite journal | vauthors = Lefton-Greif MA, Crawford TO, McGrath-Morrow S, Carson KA, Lederman HM | title = Safety and caregiver satisfaction with gastrostomy in patients with Ataxia Telangiectasia | journal = Orphanet Journal of Rare Diseases | volume = 6 | pages = 23 | date = May 2011 | pmid = 21569628 | pmc = 3116459 | doi = 10.1186/1750-1172-6-23 }} 68. ^{{cite journal | vauthors = Chessa L, Leuzzi V, Plebani A, Soresina A, Micheli R, D'Agnano D, Venturi T, Molinaro A, Fazzi E, Marini M, Ferremi Leali P, Quinti I, Cavaliere FM, Girelli G, Pietrogrande MC, Finocchi A, Tabolli S, Abeni D, Magnani M | title = Intra-erythrocyte infusion of dexamethasone reduces neurological symptoms in ataxia teleangiectasia patients: results of a phase 2 trial | journal = Orphanet Journal of Rare Diseases | volume = 9 | issue = 1 | pages = 5 | date = January 2014 | pmid = 24405665 | pmc = 3904207 | doi = 10.1186/1750-1172-9-5 }} 69. ^{{cite journal | vauthors = Yousefpour P, Chilkoti A | title = Co-opting biology to deliver drugs | journal = Biotechnology and Bioengineering | volume = 111 | issue = 9 | pages = 1699–716 | date = September 2014 | pmid = 24916780 | pmc = 4251460 | doi = 10.1002/bit.25307 }} External links{{Medical resources| DiseasesDB = 1025 | ICD10 = {{ICD10|G|11|3|g|10}} | ICD9 = {{ICD9|334.8}} | ICDO = | OMIM = 208900 | MedlinePlus = 001394 | eMedicineSubj = derm | eMedicineTopic = 691 | eMedicine_mult = {{eMedicine2|oph|319}} | MeshID = D001260 | GeneReviewsNBK = NBK26468 | GeneReviewsName = Ataxia-telangiectasia | Orphanet = 100 }}
8 : Chromosome instability syndromes|Genodermatoses|Systemic atrophies primarily affecting the central nervous system|Neurodegenerative disorders|IUIS-PID table 3 immunodeficiencies|DNA replication and repair-deficiency disorders|Syndromes affecting the nervous system|Syndromes with tumors |
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