The second of 2 siblings with hypoplasia of the tricuspid valve and right ventricle is described in detail, and the case of the first sibling is summarized. Review of the literature indicates a highincidence of occurrence of this malformation in siblings.
Bibliographical noteFunding Information:
From the Department of Pediatrics, Tufts University School of Medicine, and New England Medical Center Hospitals (Boston Floating Hospital \[or Infants and Children). Supported in part by a grant from the National Foundation.