Localization of the genetic locus for Saethre-Chotzen syndrome to a 6 cM region of Ihromosome 7 using four cases with apparently balanced translocations at 7p21.2

Abstract

Saethre - Chotzen syndrome is a common autosomal dominant form of cranlosynostosls, which results In the premature fusion of cranial sutures. Cranlosynostosls is commonly associated with abnormalities of 7p; Vortkamp et al. (Nature 352, 539 – 540) demonstrated that the GLI3 gene In 7p13 was disrupted in, patients with Greig syndrome and, more recently, the linkage of genetic markers from 7p with the Saethre - Chotzen syndrome locus has been reported (2, 3). Here we report the analysis by fluorescence In situ hybridization of four patients with Saethre-Chotzen syndrome associated with apparently balanced translocatlons Involving band 7p21.2 and different reciprocal chromosomes. We show that In all four patients the breakpoints in 7p are situated within a 6 cM region flanked by the genetic markers D7S488 and D7S493. These results provide further evidence that the genetic locus for Saethre-Chotzen syndrome is located in distal 7p.