A malformed male newborn was first diagnosed as having Smith-Lemli-Opitz syndrome. Extensive cytogenetic studies, including Q, G, C, R and T banding and BudR treatment, were applied, finally leading the authors to conclude that the patient had a partial 2p trisomy caused by direct duplication 2p14 to 2p23. This was a de novo chromosome abnormality, as both parents had normal karyotypes.

Two sibs with partial trisomy-5p are reported. Their father is the carrier of a balanced translocation 46,XY,t(4q+;5p-). Twelve cases of partial trisomy-5p--including our two patients--have been reported. The most common abnormalities found were mental retardation, short stature, dolichocephaly, prominent nasal bridge, prognathism, seizures, hypotonia, ear abnormalities, increased ulnar loops on the fingertips, and cryptorchidism in affected males.

Minor abnormalities are described in an 11-month-old female in which a "de novo" trisomy 1q32 leads to lqter and a monosomy 3p25 leads to ter has been produced. The amount of the exceeding material in this case is less than that found in previous reports of partial trisomy 1q and in cases of parental 1q balanced translocations which has originated recurrent abortions.

No abstract