词条 | Allelic heterogeneity |
释义 |
Mutated alleles expressing allelic heterogeneity can be classified as adaptive or disadaptive. These mutations can occur in the germ line cells, somatic cells, or in the mitochondrial. Mutations in germ line cells can be inherited as well as mitochondrial allelic mutations. The mitochondrial allelic mutations are inherited maternally. Typically in the human genome a small amount of allele variants account for ~75% of the mutations found at a particular locus within a population. Other variants found are considered to be rare or exclusive to a single pedigree. The Online Mendelian Inheritance of Man has a record of over 1000 genes and their associated allelic variants. These genes display allelic heterogeneity at their loci and are responsible for distinct disease phenotypes. Some of these diseases include alkaptonuria, albinism, achondroplasia, and phenylketonuria.[2][3] For example, β-thalassemia may be caused by several different mutations in the β-globin gene. Allelic heterogeneity should not be confused with locus heterogeneity in which a mutation at a different gene causes a similar phenotype. Nor should it be confused with phenotypic heterogeneity in which a mutation within the same gene causes a different phenotype. Other major diseases displaying allelic heterogeneity are allelic mutations in the dystrophin gene which cause Duchenne dystrophy and mutations in the CFTR gene that are known to causes cystic fibrosis.[4] AlkaptonuriaThe human gene for the HGD nucleotide sequence shows a number of AKU-causing allelic mutations. Approximately 40 different allelic variants have been documented. Most of these variants do not have an effect on the enzyme catalysis function. A few known alleles have an indirect effect on protein function by causing misfolding and disrupt the proper assembly of the enzyme complex. Alkaptunoria is considered to be a classic example of allelic heterogeneity showing a single variant in the human phenotype.[5] See also
References1. ^{{cite book|last1=Singh|first1=Abinash|title=Encyclopedia of Behavioral Medicine: Allelic Heterogeneity|date=2013|publisher=Springer|location=New York|pages=66–67}} {{genetics-stub}}2. ^{{cite book|last1=Scriver|first1=Charles R|title=Encyclopedia of Life Sciences|date=2005|publisher=John Wiley & Sons Ltd.|location=Etobicoke, Canada}} 3. ^"Genetics Home Reference", 25 September 2009, Allelic heterogeneity, 29 September 2009 4. ^{{cite book|last1=Singh|first1=Abinash|title=Encyclopedia of Behavioral Medicine: Allelic Heterogeneity|date=2013|publisher=Springer|location=New York|pages=66–67}} 5. ^{{cite book|last1=Scriver|first1=Charles R|title=Encyclopedia of Life Sciences|date=2005|publisher=John Wiley & Sons Ltd.|location=Etobicoke, Canada}} 1 : Mutation |
随便看 |
|
开放百科全书收录14589846条英语、德语、日语等多语种百科知识,基本涵盖了大多数领域的百科知识,是一部内容自由、开放的电子版国际百科全书。