[Molecular-genetic characteristics of the deleted region of chromosome 8q24.1 in Langer-Giedion and tricho-rhino-phalangeal type I syndromes].

A molecular-genetic characterization of deletions in part of chromosome 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, analysis. Four families with multiple exostosis chondrodysplasia (MECD) also underwent the same analysis. Results of deletion mapping allowed determination of the probable region of localization of the proposed gene of MECD at D8S67 locus. By means of a polymorphic DNA probe obtained from the locus an additional hybridization signal was revealed only in patients with MECD. Other polymorphic DNA probes and microsatellite sequences confirmed the results of deletion mapping and detected haplotypes on the chromosomes with a mutation in the proposed MECD gene.