MOLECULAR CYTOGENETIC DIAGNOSIS OF WILLIAMS-SYNDROME

Williams syndrome (WS) is characterized by distinct facial changes, gr owth deficiency, mental retardation, and congenital heart defect (part icularly supravalvular aortic stenosis), associated at times with infa ntile hypercalcemia, Molecular genetic studies have indicated that hem izygosity at the elastin locus (7q11.23) causes WS, The purpose of thi s study was to confirm that this regional deletion, involving the elas tin locus, is the cause of WS in Japan, and to clarify the correlation between the phenotype and the elastin locus. Thirty-two patients with WS and thirty of their relatives were examined by fluorescent in situ hybridization (FISH), using the WS chromosome region (WSCR) probe, Al l patients had cardiovascular disease (100%), 30 had typical WS facial changes (94%), 31 had mental retardation or developmental delay (97%) , 16 were small-for-date at birth (50%), 14 had short stature (44%), a nd 13 had dental anomalies (41%), No relatives showed any manifestatio n of WS. Hemizygosity for a region of 7q11.23, involving the elastin l ocus, was found in all WS patients, but was not found in the 30 relati ves. (C) 1996 Wiley-Liss, Inc.