This T-to-A point mutation at position 5503 of the Ap2b1 (adaptor-related protein complex 2, beta 1 subunit) cDNA was identified in an ENU screen for recessive cardiovascular development phenotypes in Dr. Cecilia Lo's laboratory, NHLBI Cardiovascular Development Consortium (CvDC). It was recovered from G1 sperm and associated with the phenotype described described here. Because G1 sperm were cryopreserved, additional incidental mutations are also segregating in this strain.
Homozygotes demonstrate overriding aorta/double outlet right ventricle (DORV, Taussig-Bing subtype) with atrioventricular septal defect (AVSD), perimembranous ventricular septal defect (VSD), right aortic arch (RAA), and ventricular hypertrophy. Micrognathia, cleft palate, and hypoplastic thymus are also seen.