Mutations in the pterin-4alpha-carbinolamine dehydratase (PCBD) gene cause a benign form of hyperphenylalaninemia.
Thöny B, Neuheiser F, Kierat L, Rolland MO, Guibaud P, Schlüter T, Germann R, Heidenreich RA, Duran M, de Klerk JB, et al. Hum Genet. 1998 Aug; 103(2):162-7.