5 α-reductase deficiency is a rare autosomal recessive condition of male psuedohermaphroditism, resulting from mutations of the type 2 isoenzyme 5 α-reductase, crucial in conversion of testosterone to dihydrotestosterone
Case report: Baby P is a full term baby, a product of a consanguineous marriage. The baby had ambigous genitalia with a clitoris, minimal glans tissue at the apex of the labial folds, gonads in the labioscrotal folds and a urethral opening below the clitoris1. Pelvic ultrasound demonstrated absence of mullerian structures. Due to the female phenotypic appearance of the genitalia the parents initially opted to raise the baby as a female. Biochemistry revealed a serum testosterone of 11.9 nmol/l and serum dihydrotestosterone was undetectable at <0.125 nmol/l. Karyotype was XY. Urinary steroid profile was normal. A diagnosis of 5 α-reductase deficiency was made. Management was decided based on a consensus between the parents socio-cultural views and the medical perspectives of the adult and paediatric endocrinologists and the clinical geneticist. Rearing the baby as a female would involve early surgery to remove the gonads thus eliminating the testosterone drive to prevent further virilization and genitoplasty. However, this would result and the impact of androgen exposure to the brain in utero loss resulting in gender identity problems and permanent infertility in the future. Rearing the baby as a male would involve using DHT cream for virilization of the external genitalia and surgical correction of hypospadias, with preservation of fertility. The parents and the medical team agreed that rearing the baby as a male would be the best option. Daily application of DHT cream for 3 months to the external genitalia resulted in virilization in the form of clitoromegaly reaching a phallus length 2 S.D. below the average male baby. Surgical correction of the peno-scrotal hypospadias is the next therapeutic stage.
Summary: Our case illustrates an uncommon cause of male pseudohermaphroditism. Management issues are based on social and cultural factors of the parents, the role of in utero androgen exposure to the brain, the importance of androgens in the evolution of male gender identity in man and the preservation of potential fertility.
01 - 05 Apr 2006
European Society of Endocrinology