A GENE FOR HEREDITARY MULTIPLE EXOSTOSES MAPS TO CHROMOSOME 19P

Hereditary multiple exostoses (EXT) is an autosomal dominant bony diso rder characterized by the formation of cartilage-capped juxta-epiphyse al prominences on the long bones. Recently, a disease gene (EXT 1) has been mapped to chromosome 8q23 - q24 by linkage analysis in informati ve families. Here, we report on the genetic mapping of a second locus (EXT 2) to the short arm of chromosome 19 by linkage to a microsatelli te DNA marker at the D19S221 locus, which gives additonal support to t he view that EXT is a genetically heterogeneous condition.