Non-reciprocal translocation (5;15), isodicentric (15) and Prader-Willi syndrome

A non-reciprocal translocation (5;15) and an isodicentric (15) resulting in trisomy 15pter→15ql?3 and monosomy 5qter [46,XY,−5,−15,+der(5)t(5;l5)(5pter→5q35::15q13→15qter),+idic(15)(pter→ql?3::ql?3→ pter)] was found in a 28-year-old profoundly retarded male resident of a state institution. Early developmental history and childhood and adult physical findings resembled those of Prader-Willi syndrome (PWS) patients. The parents' unbanded chromosomes were normal. Blood groups of parents and propositus were uninformative with regard to identifying gene deletions or duplications.