A recent survey of the 3p25-ter deletion does not definitively localize the putative AVSD-specific locus to CRELD1, which suggests that there may be unappreciated gene regulatory elements which when halpoinsufficient confer risk for CHD, or that a CRELD1 AVSD-specific interval is incompletely penetrant Shuib et al., 2009. This evidence concerns the gene CRELD1 and familial atrioventricular septal defect.