Establishment of testicular endocrine function impairment during childhood and puberty in boys with Klinefelter syndrome

BASTIDA, M.G.; REY, R.; BERGADÁ, I.; BEDECARRÁS, P.; ANDREONE, L.; DEL REY, G.; BOYWITT, A.; ROPELATO, M.G.; CASSINELLI, H.; ARCARI, A.; CAMPO, S.; GOTTLIEB, S.

CLINICAL ENDOCRINOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Año: 2007 vol. 67 p. 863 - 870

0300-0664

Objective: To precisely characterise the chronology of testicular endocrine function impairment during childhood and adolescence in patients with Klinefelter syndrome. Design: Retrospective chart review. Patients: 29 boys with Klinefelter syndrome with up to 12.3-yr follow-up. Measurements: Clinical features and serum hormone levels were analyzed during follow-up. Results: Sixteen patients were prepubertal and 13 had already entered puberty at their first visit. Fifteen out of 29 patients were followed up through late puberty. Before puberty, LH, FSH, testosterone, anti-Müllerian hormone (AMH) and inhibin B were within the expected range in almost all cases. However, levels of the inhibin a subunit precursor Pro-aC were in the lowest levels of the normal range in most cases. During puberty, FSH levels increased earlier and more markedly than LH. Inhibin B and AMH declined to abnormally low or undetectable levels in advanced pubertal stages. Although testosterone and Pro-aC levels were within the reference ranges in most cases, they were abnormally low for the observed LH values. Conclusions: In Klinefelter syndrome, a mild Leydig cell dysfunction is present from early childhood in most cases and persists throughout puberty. Sertoli cell function is normal until mid-puberty, when a dramatic impairment is observed.