Identification of a New Candidate Locus for Ebstein Anomaly in 1p36.2.

Ebstein anomaly (EA) is a rare congenital heart defect (CHD) with a poorly characterized genetic etiology. However, some EA patients carry deletions in 1p36, all of which have been reported to carry distal deletions and share loss of the gene, which is currently considered the most likely candidate for EA development in this region. Here, we report a patient with an 11.96-Mb proximal 1p36 deletion, without loss of , who presented with EA and a proximal deletion phenotype. This finding suggests that loss is not required for the development of EA in 1p36 deletions and that the loss of an additional proximal locus in 1p36 is also likely associated with EA. Our data suggest that a distal locus containing the gene and a proximal locus containing the CHD-associated genes and are the most probable etiological factors for EA in patients with 1p36 deletion syndrome.