Phenotypes with GATA4 or NKX2.5 mutations in familial artrial septal defect

Recently, GATA4 and NAX2.5 were reported as the disease genes of atrial septal defect (ASD) but the relationship between the locations of their mutations and phenotypes is not clear. We analyzed GATA4 and NAX2.5 mutations in 16 familial ASD cases, including four probands with atrioventricular conduction disturbance (AV block) and two with pulmonary stenosis (PS), by PCR and direct sequencing, and examined their phenotypes clinically. Five mutations, including two GATA4 and three NAX2.5 mutations, were identified in 31.3% of the probands with ASD, and three of them were novel. The two GATA4 mutations in the probands without AV block were S52F and E359Xfs (c.1075delG) that was reported previously, and three NKX2.5 mutations in the probands with AV block were A88Xfs (c.262delG), R190C, and T178M. Additionally, we observed some remarkable phenotypes, i.e., dextrocardia with E359Xfs (c.1075delG) and cribriform type ASD with R190C, both of which are expected to be clues for further investigations. Furthermore, progressive, most severe AV block was closely related with a missense mutation in a homeodomain or with a nonsense/frame-shift mutation of NAX2.5 for which classification has not been clearly proposed. This pinpoints essential sites of NKX2.5 in the development of the conduction system. (c) 2005 Wiley-Liss, Inc.