Congenital heart defects in siblings with partial aneuploidy of chromosome 2p

Cytogenetic anomalies are found in 13% of children with congenital heart disease, providing positional information that may aid in identifying genes governing cardiac development. We report two children born to a clinically normal female with a balanced chromosomal rearrangement, resulting from insertion of 2p24.2–p25.1 into chromosome 1. Each of her offspring had complex congenital heart disease, including left ventricular hypoplasia, and inherited a different copy number of the 2p segment. These findings suggest that proper dosage of a gene or genes in this region is important in normal cardiac development.