Primary amenorrhea in four adolescents revealed 5α-reductase deficiency confirmed by molecular analysis.

OBJECTIVE: To determine the genetic cause of primary amenorrhea.

DESIGN: Case series.

SETTING: Pediatric endocrinology, endocrinology, and gynecology departments of academic hospitals.

PATIENT(S): Three adolescents and one young woman 46, XY patients with srd5A2 gene mutations.

MAIN OUTCOME MEASURE(S): Genetic analysis of srd5A2.

RESULT(S): We report four srd5A2 gene mutations in three adolescents and one young woman with 46,XY primary amenorrhea. All presented clitoromegaly and two presented hypospadias; all had been reared as females. Virilization of the external genitalia was noted in the pubertal period in all four patients. Three were maintained in the female sex of rearing by personal choice, and the fourth switched gender. We identified the homozygous substitutions p.L55Q (exon 1), p.Q56R (exon 1), and p.N193S (exon 4), in patients 1, 2, and 3, respectively. Patient 4 had compound heterozygous mutations, a new c.34delG (exon 1) associated with p.R246W (exon 5). All patients had high plasma T levels (ranges, 16.2-23.2 nmol/L; normal female teenage range, 0.35-2 nmol/L).

CONCLUSION(S): Our data clearly demonstrate that 5α-reductase deficiency should be considered in XY adolescents with primary amenorrhea and no breast development associated with virilization at puberty and high plasma T. Positive parental consanguinity should reinforce the diagnostic orientation.