11β-hydroxylase deficiency (11β-OHD) caused by mutations in the CYP11B1 gene accounts for approximately 5–8 % of congenital adrenal hyperplasia (CAH) in non-consanguineous populations, but accounts for ~15 % of cases in both Muslim and Jewish Middle Eastern populations [1]. The gene discussed is CYP11B1; the disease is congenital adrenal hyperplasia.