Inheritance of skewed X chromosome inactivation in a large family with an X-linked recessive deafness syndrome

✍ Scribed by Ørstavik, Karen Helene; Elise Ørstavik, Ragnhild; Eiklid, Kristin; Tranebjærg, Lisbeth

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 19 KB
• Volume: 64
• Category: Article
• ISSN: 0148-7299
• DOI: 10.1002/(sici)1096-8628(19960712)64:1<31::aid-ajmg4>3.0.co;2-u

✦ Synopsis

A new X-linked recessive deafness syndrome was recently reported and mapped to Xq22 (Mohr-Tranebjaerg syndrome). In addition to deafness, the patients had visual impairment, dystonia, fractures, and mental deterioration. The female carriers did not have any significant manifestations of the syndrome. We examined X chromosome inactivation in 8 obligate and 12 possible carriers by using a polymerase chain reaction analysis of the methylation-dependent amplification of the polymorphic triplet repeat at the androgen receptor locus. Seven of 8 obligate carriers and 1 of 5 carriers by linkage analysis had an extremely skewed pattern in blood DNA not found in 30 normal females. The X inactivation pattern in fibroblast DNA from 2 of the carriers with the extremely skewed pattern was also skewed but to a lesser degree than in blood DNA. One obligate carrier had a random X inactivation pattern in both blood and fibroblast DNA. A selection mechanism for the skewed pattern is therefore not likely. The extremely skewed X inactivation in 8 females of 3 generations in this family may be caused by a single gene that influences skewing of X chromosome inactivation.