Tandem dup (1p) within the short arm of chromosome 1 in a child with ambiguous genitalia and multiple congenital anomalies.

A newborn infant was found to have multiple congenital anomalies including bilateral cleft of lip and palate, intrauterine growth retardation, microcephaly, tetralogy of Fallot, ambiguous external genitalia, and presence of male and female internal genitalia. Chromosome analysis showed a tandem duplication of part of the short arm of chromosome 1, resulting in a dup(1p31----35). The karyotype designation is 46,XY,dir dup(pter----31::p35----p31::p31----qter). The exact nature of the chromosome anomaly was clarified with use of several banding methods.