Campomelic syndrome and deletion of SOX9.

The human SOX9 gene, located in chromosome region 17q24.1-25.1, encodes a transcription factor involved in chondrogenesis and testis development. Mutations in this gene cause campomelic syndrome (CMPS) with autosomal sex reversal. Here we describe an infant girl with CMPS and an interstitial deletion on the long arm of chromosome 17 (46,X,del(17)(q23.3q24.3). The extent of SOX9 deletion on one chromosome 17 was defined using unique sequence fluorescent in situ hybridization probes. This is the first report of a patient with CMPS bearing a complete deletion of one SOX9 gene, and as such is the strongest evidence to date for dose-dependent action of the SOX9 protein in normal chondrogenesis.

Harlequin Ichthyosis among the Navajo: Counseling issues.

Harlequin Ichthyosis is a rare, fatal congenital disorder of keratinization characterized by thickened, scale-like plaques of skin with a diamond configuration. Autosomal recessive inheritance has been established, and prenatal diagnosis for this disorder remains controversial. Five infants with this disorder were born among approximately 25,000 Navajo women who delivered in Gallup, New Mexico from 1970 to 1989. The incidence of 1 in 5000 among the Navajo in Gallup is high compared to previous reports in other populations. Two families with affected infants were seen in a genetics outreach clinic. Two important counseling issues were raised: (1) reluctance to discuss the possibility of recurrence for fear of affecting the outcome, and (2) feelings of guilt caused by cultural beliefs which attributed the birth defect to paternal behavior during pregnancy. Such issues are encountered in many traditional cultures, and they can be addressed by tailoring the timing and content of counseling.