identify disease-causing alleles. Gene-duplication events, leading to multiple functional and/or non-functional genetic copies in the genome, can significantly complicate polymerase chain reaction (PCR)-based genotyping assays. Transgenic animal models have permitted the exploration of the functions of ALDHs under in vivo physiological and pathophysiological conditions [2]. These invaluable studies are heavily dependent upon our understanding of the mouse and human genomes. In addition to mutations in ALDH genes within populations, there is a large variation in the number of ALDH genes between species.
