Besides the challenging decisions about the need to perform genital surgery, 46,XX CAH individuals due to CYP11B1 deficiency, if left untreated, develop hypertension and progressive virilization of the external genitalia and a male appearance with serious physical and psychosexual consequences, such as disturbed pubertal development, menstrual disturbances, decreased fecundity. The gene discussed is CYP11B1; the disease is hyperinsulinemic hypoglycemia, familial, 4.