LOCALIZATION OF THE BANNAYAN-RILEY-RUVALCABA-SYNDROME GENE TO CHROMOSOME 10Q23

Background & Aims: Bannayan-Riley-Ruvalcaba syndrome is a congenital s yndrome with characteristic features of macrocephaly, cognitive and mo tor dysfunction, subcutaneous and visceral lipomas and hemangiomas, an d intestinal juvenile polyposis. It has been suggested that Bannayan-R iley-Ruvalcaba syndrome may be a variant of juvenile polyposis coli be cause of the shared features of intestinal juvenile polyps. The aim of this study was to precisely map loss of DNA from 2 patients with inte stinal juvenile polyposis and karyotypic abnormalities involving chrom osome 10q. Methods: DNA was extracted from peripheral leukocytes drawn from each patient and each patient's biological parents. The DNA was amplified by polymerase chain reaction using primers specific for micr osatellites located on chromosome 10q. Results: Precise mapping locali zed a maximal distance of 1.0 cM that was commonly deleted from each p atient's genome, between D10S541 and D10S1735. This area overlaps the region for Cowden disease, a distinct hamartomatous intestinal polypos is syndrome with increased risk of breast and thyroid carcinoma. Concl usions: The three hamartomatous polyposis syndromes, Bannayan-Riley-Ru valcaba syndrome, juvenile polyposis coli, and Cowden disease, may sha re the same genetic defect because of their common map localization to chromosome 10q23.