A MOLECULAR-GENETIC DESCRIPTION OF THE RE GION OF DELETIONS IN CHROMOSOME 8Q24.1 IN LANGER-GIEDION SYNDROME AND TRIHO-RHINO-PHALANGEAL SYNDROME TYPE-I

A molecular-genetic characterization of-deletions in part of chromosom e 8q24.1. was performed in patients with Langer-Giedion syndrome (six patients) and triho-rhino-phalangeal syndrome type I (three patients) by means of Southern blot hybridization analysis, restriction fragment length polymorphism and single-strand conformation polymorphism, anal ysis. Four families with multiple exostosis chondrodysplasia (MECD) al so underwent the same analysis. Results of deletion mapping allowed de termination of the probable region of localization of the proposed gen e of MECD at D8S67 locus. By means of a polymorphic DNA probe obtained from the locus an additional hybridization signal was revealed only i n patients with MECD. Other polymorphic DNA probes and microsatellite sequences confirmed the results of deletion mapping and detected haplo types on the chromosomes with a mutation in the proposed MECD gene.