Numerous chromosome abnormalities have been found in association with congenital diaphragm abnormalities [12,35]. Human FOG2 maps to Chromosome 8q23.1, and, importantly, several patients with diaphragm defects and rearrangements involving this locus have been reported. Specifically, there are three unrelated CDH patients with cytogenetically balanced translocations at or near the FOG2 locus [36,37]. Additionally, two patients with deletions apparently encompassing the FOG2 locus have died from multiple congenital anomalies including CDH [38–40]. Inactivation of this gene due to chromosomal rearrangement or deletion would result in a heterozygous null mutation similar to that found in the patient we report.