GATA4 and Down syndrome: Before the first wave of genome-wide CNV studies, the 8p deletion syndrome and sequence mutations in GATA4 were both reported to be associated with CHD.14,71,72 Haploinsufficiency of GATA4 is now one of the most frequent rare structural anomalies identified in genome-wide CNV studies of CHD.34,39,41,47,48,50,52,58 Unlike the typical chromosomal rearrangements at 1q21.1, 15q11.2 and 22q11.2 mediated by non-allelic homologous recombination, these 8p deletions are non-recurrent and of varying size.