Most of the patients (96 of 104, 92%) had a genetically confirmed diagnosis of CAH due to 21-hydroxylase (CYP21A2) deficiency in 94 patients (90%), 11-β-hydroxylase (CYP11B1) deficiency in 1 patient (1%), and P450 oxidoreductase (POR) deficiency in 1 patient (1%). The gene discussed is CYP11B1; the disease is hyperinsulinemic hypoglycemia, familial, 4.