Mosaic monosomy of a neocentric ring chromosome maps brachyphalangy and growth hormone deficiency to 13q31.1-13q32.3

Autor: Ravi Savarirayan, David J. Amor, Lucille Voullaire, K. H. Andy Choo, Karen Bentley
Rok vydání: 2005
Předmět:
Zdroj: American Journal of Medical Genetics Part A. :151-157
ISSN: 1552-4833
1552-4825
DOI: 10.1002/ajmg.a.30527
Popis: We describe a boy with moderate intellectual disability associated with distinctive hand malformations (hypoplastic and angel-shaped middle phalanges) and partial growth hormone (GH) deficiency associated with mosaic deletion of 13q31.1-13q32.3. The deleted segment was mapped to a 20-Mb region bounded by BACs RP11-1143C2 and RP11-139C1, narrowing the previously described locus for hand malformations at this region and suggesting that a locus for GH deficiency is also present at this location. The deleted segment contains at least three candidate genes, glypican-5, FARP1 and SOX21, that may be contributing to the phenotype in this boy. In a significant proportion (approximately 50%) of cells, the deleted region is present as a supernumerary ring chromosome stabilized by the formation of a neocentromere at 13q31-q32, within a region with a known propensity for neocentromere formation. The ring chromosome appears to be prone to low-level misdivision and loss in vitro which, in vivo, must be countered by selection for the balanced karyotype because the level of mosaicism has remained stable over 13 years.
Databáze: OpenAIRE
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