PAH and phenylketonuria: Over 1000 variants in the PAH gene have been associated with PKU in the PAHvdb (Phenylalanine Hydroxylase Gene Locus‐Specific Database, PAHdb; http://www.pahdb.mcgill.ca/), and BIOPKU (http://www.biopku.org) databases, primarily from Caucasian populations (Blau et al., 2014).