ESPE Abstracts

Background: Pubertal gynecomastia is observed in up to 65% of adolescent males. It is usually idiopathic and tends to regress within 1–2 years, although sometimes pubertal gynecomastia persists.

Case presentation and methods: We investigated three adolescent males with isolated persistent pubertal gynecomastia: twin brothers and an unrelated adolescent boy. The twins (17 years) had normal male external genitalia. Biological testing showed normal testosterone concentration (4.1 and 3.8 ng/ml respectively) and normal response to the HCG stimulation test (10.3 and 13 ng/ml respectively). The gonadotropin level was normal. Spermatogenesis investigations revealed azoospermia in one of the brothers and oligospermia in the other. The third adolescent boy (16 years) presented normal male external genitalia. Biological investigations showed normal testosterone level (3.6 ng/ml) and no other sign of alteration. No evidence of spermatogenesis failure was documented.

Results: For the twins, genetic analysis of the AR gene revealed a c.1937C>A mutation in the hinge region leading to a substitution of an alanine by aspartic acid: p.Ala646Asp. This mutation was transmitted by their mother. She presented no sign other than very sparse pubic hair. For the third adolescent, genetic analysis of the AR gene identified the c.134C>G substitution resulting in a p.Ala45Gly change in amino acid. This mutation was transmitted by his mother. The maternal family history revealed a first cousin with bilateral mastectomy for persistent and prominent bilateral gynecomastia.

Conclusions: These data suggest that persistent pubertal gynecomastia should be investigated to identify a possible defect of the AR gene.