Brief clinical report: deletion of the long arm of chromosome 11, [del(11)(q23)].

We report sporadic occurrence of deletion of the long arm of chromosome 11 (q23 leads to qter) in a male newborn infant with intrauterine growth retardation, craniofacial, cardiac, and orthopedic abnormalities and neonatal death but without genital abnormalities. This deletion is seen predominantly in females; here we emphasize the importance of an XX sex chromosome constitution as a factor determining phenotypic expression of and survival in the del(11q) syndrome. We also provide a description of the cardiovascular system from postmortem examination. The cardiac findings are similar to those of two previously autopsied cases and will assist in early clinical diagnosis of the 11q-syndrome.