FRAGILE-X PHENOTYPE IN A PATIENT WITH A LARGE DE-NOVO DELETION IN XQ27-Q28

A 2-year-old boy with manifestations of the fragile X syndrome was fou nd to have a cytogenetically visible deletion of Xq27-q28 including de letion of FMR-1. Molecular analysis of the patient was recently descri bed in Tarleton et al. [1993: Hum Mol Genet 2(11): 1973-1974] and the deletion was estimated to be at least 3 megabases (Rib). His mother ha d 2 FMR-1 alleles with normal numbers of CGG repeats, 20 and 32, respe ctively. Thus, the deletion occurred as a de novo event. The patient d oes not appear to have clinical or laboratory findings other than thos e typically associated with fragile X syndrome, suggesting that the de letion does not remove other contiguous genes. This report describes t he phenotype of the patient, including psychological studies. (C) 1994 Wiley-Liss, Inc.