Di George Anomaly and Velocardiofacial Syndrome

Abstract

The velocardiofacial syndrome is an autosomal dominant disorder characterized by cleft palate, cardiac anomalies, characteristic facies, and learning disabilities. The Di George anomaly involves developmental defects of the third and fourth pharyngeal pouches, resulting in thymic and parathyroid hypoplasia and cardiac defects. The cases of individuals in two families help substantiate the notion that the Di George anomaly occurs as a feature of the velocardiofacial syndrome. The proband in family 1 was a male infant with persistent hypocalcemia and cardiac defects consisting of truncus arteriosus, atrial septal defect, ventricular septal defect, and abnormal aortic arch vessels. Autopsy revealed absence of thymic and parathyroid tissue, and the Di George anomaly was diagnosed. His father had a submucous cleft palate, T cell dysfunction, and facial features consistent with the velocardiofacial syndrome. This is the third case of male-to-male transmission of velocardiofacial syndrome. The proband of family 2 was a 4-year-old girl with developmental delay, persistent neonatal hypocalcemia, ventricular septal defect, T cell dysfunction, and facial features of the velocardiofacial syndrome. The Di George anomaly has been reported to occur in at least 18 different disorders. The observation that the Di George anomaly is a component manifestation of the velocardiofacial syndrome in these two families provides further evidence that the Di George anomaly is not a distinct syndrome of a single origin but rather a heterogeneous developmental field defect. It is proposed that all previously reported cases of autosomal dominant Di George anomaly are examples of the velocardiofacial syndrome.