Are Klinefelter boys hypogonadal ?

RODOLFO A. REY; SILVIA GOTTLIEB; TITANIA PASQUALINI; MARÍA GABRIELA BASTIDA; ROMINA P. GRINSPON; STELLA M. CAMPO; IGNACIO BERGADÁ

ACTA PAEDIATRICA

WILEY-BLACKWELL PUBLISHING, INC

Lugar: OSLO; Año: 2011 vol. 100 p. 830 - 838

0803-5253

Male hypogonadism implies decreased testicular function involving germ cell production and/or Leydig and/or Sertoli cell function. In the normal prepubertal boy, Sertoli cells are very active, as indicated by high anti-Müllerian hormone (AMH) and inhibin B secretion, whereas the functional activity of Leydig cells is minimal, as evidenced by low testosterone production, and germ cells do not undergo the full spermatogenic process. Klinefelter syndrome is the most frequent cause of hypogonadism in the adult male. In this review, we discuss whether the gonadal failure is already established during infancy and childhood. Germ cells degenerate from mid-fetal life, resulting in decreased numbers at birth. Cell degeneration persists during infancy and childhood and becomes dramatic during puberty. Controversial results exist in the literature regarding Leydig cell function in Klinefelter boys: while some authors have found normal to low testosterone levels in infancy and childhood, others have reported normal to high values. Sertoli cell products AMH and inhibin B are normal in prepubertal boys and only decline during mid- to late puberty. Conclusion: Klinefelter syndrome is a primary hypogonadism affecting all testicular cell populations. Germ cells are affected from fetal life, and a severe depletion occurs at puberty. Leydig cell function may be normal or mildly affected in fetal and early postnatal life. Sertoli cell function is not impaired until mid- to late puberty, as reflected by normal AMH and Inhibin B in Klinefelter boys.