CYP11β1 (11-beta-hydroxylase) deficiency in congenital adrenal hyperplasia

Objective: To review experience of CYP11β1 deficiency (previously known as 11β-hydroxylase) at the Royal Children's Hospital, Melbourne, Victoria. Methodology: A retrospective case review was conducted from 1974 to 1995 with five cases identified. Results: Age of presentation ranged from 1 day to 7 years. Presentation was with ambiguous genitalia at birth (two females), simple virilization (two males) and suspected early puberty in mid childhood (one female). Associated clinical features were hypertension (three cases) and tall stature with markedly advanced bone age (four cases). Biochemical abnormalities consistent with CYP11β1-deficiency were elevated urinary tetrahydro-11-deoxycortisol (n = 5) and elevated serum 11-deoxycortisol (n = 3). Additional abnormalities were elevated 17-hydroxyprogesterone (n = 3), elevated androstenedione (n = 4) and elevated dehydroepiandrosterone sulphate (n = 4). The clinical features and investigations suggested CYP11β1-classical deficiency in four patients and CYP11β1-non-classical deficiency in one patient. Conclusions: The five cases of CYP11β1-deficiency demonstrate a spectrum of clinical abnormalities, with diagnostic difficulties in two cases and delayed presentation in three cases. Prompt diagnosis of CYP11β1-deficiency is facilitated greatly by the availability of a gas chromatography-mass spectrometry instrument and is essential to avoid the long-term effects of hypertension and hyperandrogenism.