[[3][4]] Characteristics
Parastremmatic dwarfism is apparent at birth, with affected infants usually being described as "stiff", or as "twisted dwarfs" when the skeletal deformities and appearance of dwarfism further present themselves. Skeletal deformities usually develop in the sixth to twelfth month of an infant's life. The deformities may be attributed to osteomalacia, a lack of bone mineralization.
Cause and genetics
Parastremmatic dwarfism is caused by a missense mutation (where one amino acid is replaced by another in a gene sequence) in the TRPV4 gene,[4] located on the long arm of human chromosome 12, at 12q24.11.[6] The mutation is in exon 11 of the gene, and is labelled R594H; this means that the codon (the code for an amino acid molecule) for arginine was erroneously substituted by a codon for histidine at position 594 in that exon. This same mutation in the TRVP4 gene is known to cause the Kozlowski type of spondylometaphyseal dysplasia.[4][8]
Parastremmatic dwarfism is inherited in an autosomal dominant manner,[9] which means that the defective gene responsible for the disease is located on an autosome (chromosome 12 is an autosome), and one copy of the defective gene is sufficient to cause the disorder when inherited from a parent who also has the disorder.
{{clear}}Diagnosis
{{Empty section|date=August 2017}}Treatment
{{Empty section|date=August 2017}} References
1. ^1 {{Cite journal | last1 = Langer | first1 = L. O. | last2 = Petersen | first2 = D. | last3 = Spranger | first3 = J. | title = An unusual bone dysplasia: Parastremmatic dwarfism | journal = The American Journal of Roentgenology, Radium Therapy, and Nuclear Medicine | volume = 110 | issue = 3 | pages = 550–560 | date = Nov 1970 | url = http://www.ajronline.org/content/110/3/550.full.pdf+html | format = Free full text| pmid = 4992387}}
2. ^1 2 3 {{Cite journal | last1 = Nishimura | first1 = G. | last2 = Dai | first2 = J. | last3 = Lausch | first3 = E. | last4 = Unger | first4 = S. | last5 = Megarbané | first5 = A. | last6 = Kitoh | first6 = H. | last7 = Kim | first7 = O. H. | last8 = Cho | first8 = T. J. | last9 = Bedeschi | first9 = F. | doi = 10.1002/ajmg.a.33414 | last10 = Benedicenti | first10 = F. | last11 = Mendoza-Londono | first11 = R. | last12 = Silengo | first12 = M. | last13 = Schmidt-Rimpler | first13 = M. | last14 = Spranger | first14 = J. | last15 = Zabel | first15 = B. | last16 = Ikegawa | first16 = S. | last17 = Superti-Furga | first17 = A. | title = Spondylo-epiphyseal dysplasia, Maroteaux type (pseudo-Morquio syndrome type 2), and parastremmatic dysplasia are caused by TRPV4 mutations | journal = American Journal of Medical Genetics Part A | volume = 152A | issue = 6 | pages = 1443–1449 | date = Jun 2010 | pmid = 20503319 }}
3. ^1 {{OMIM|168400|Parastremmatic dwarfism}} Retrieved 11-19-2011.
4. ^1 {{OMIM|605427#0003|Transient Receptor Potential Cation Channel, Subfamily V, Member 4; TRPV4}} Retrieved 11-19-2011.
5. ^1 {{cite book |title=Dysmorphic Syndromes and Constitutional Disease of the Skeleton |author1=Canepa, G. |author2=Maroteaux, P. |author3=Pietrogrande, V. |publisher=PICCIN |year=2000 |isbn=8829915025 |pages=1421–1424 |url=https://books.google.com/books?id=RMw7CqD_4g8C&pg=PA1421&dq=Parastremmatic+dwarfism&hl=en&ei=16fITrmrI4SutwfMts3jCw&sa=X&oi=book_result&ct=book-preview-link&resnum=1&ved=0CDkQuwUwAA#v=onepage&q=Parastremmatic%20dwarfism&f=false}}