Meta-Biol

• Pathways

Steroid 17-alpha-hydroxylase/17,20 lyase (CYP17A1) mediates both 17-alpha-hydroxylase and 17,20-lyase activity, allowing the adrenal glands and gonads to synthesise both 17-alpha-hydroxylated glucocorticoids and sex steroids respectively (Kagimoto et al. 1998). Defects in CYP17A1 can cause Adrenal hyperplasia 5 (AH5), a form of congenital adrenal hyperplasia (CAH), a common recessive disease due to defective synthesis of cortisol and sex steroids. Mutations causing combined 17-alpha-hydroxylase/17,20-lyase deficiency include S106P, R96W, W17*, R362C, W406R and R96Q (Lin et al. 1991, Laflamme et al. 1996, Suzuki et al. 1998, Martin et al. 2003, Brooke et al. 2006). Mutations causing isolated 17,20-lyase deficiency are R358Q and R347H (Geller et al. 1997, Van den Akker et al. 2002).