Interstitial duplication of the short arm of chromosome 1 in a newborn with congenital heart disease and multiple malformations.

Interstitial duplications of chromosomes 1p are rare, with only 14 cases previously reported in the literature, and those have not revealed a unique syndrome. The phenotypes include multiple congenital abnormalities and both intra- and extra-uterine growth retardation. In general, the patients do poorly and do not survive beyond the age of several months. We report a newborn male with karyotype 46, XY, inv dup(1)(qter--> p34.3::p34.3-->p32.3::34.3-->pter) with multiple congenital abnormalities including congenital heart disease and co-existing portal and pulmonary hypertension. The chromosome 1 origin of the extra material was confirmed with fluorescent in situ hybridization (FISH). Review of the GDB [Human Genome Database, 1990] reveals that the duplicated region includes the locus EDN2 that encodes endothelin-1, a potent vasoconstrictor, making genetic overdosage of this protein a likely etiology of the pulmonary hypertension. The diffuse abnormalities show effects in multiple cell lines and suggest that this region of chromosome 1p could be involved in determining cell migration and/or differentiation during organogenesis. Copyright 2001 Wiley-Liss, Inc.