ALDH1A2 and congenital diaphragmatic hernia: In CDH patients, CNVs have also been discovered in ALDH1A2, whose product is an enzyme that catalyzes the synthesis of retinoic acid from retinaldehyde, and in RARA and RXRA, which encode for retinoic acid receptor alpha and for Retinoid X Receptor Alpha, respectively, [39,40].