Submicroscopic 8pter deletion, mild mental retardation, and behavioral problems caused by a familial t(8;20)(p23;p13)

Microscopically visible distal 8p deletions have been associated with growt h and mental impairment, minor facial anomalies, congenital heart defects, and behavioral problems, We report two cousins with mild retardation and be havioral problems, including inappropriate sexual behavior and pyromania, F amilial learning difficulties on the grandfather's side incompatible with M endelian inheritance prompted telomere screening, which detected a submicro scopic terminal 8p deletion of < 5.1 Mb. The cousins' mothers both carried a t(8;20)(p23;p13) balanced translocation, The frequently observed microcep haly in patients with microscopically visible deletions of 8pter is lacking in both cousins, suggesting that the gene(s) causing the microcephaly is c entromeric to the deleted region. The absence of cardiac defects in the cou sins confirms the more proximal location of gene(s) causing these abnormali ties in other reported cases with microscopically visible 8pter deletions a nd supports involvement of the GATA4 gene, Moreover, the current cases pred ict the presence of a putative gene(s) involved in behavior in the most tel omeric 5.1 Mb of the p-arm of chromosome 8, This first clinical report of a submicroscopic subtelomeric 8p deletion gives more insight into the so-cal led 8p- syndrome and demonstrates the difficulty in making a clinical diagn osis for a submicroscopic 8pter deletion in an individual patient with ment al retardation (C) 2001 Wiley-Liss, Inc.