Evaluation of gonadal function in 107 intersex patients by means of serum antimullerian hormone measurement

Fetal male sexual differentiation is driven by two testicular hormones: tes tosterone (synthesized by interstitial Leydig cells) and antimullerian horm one (AMH; produced by Sertoli cells present in the seminiferous tubules). I ntersex states result either from gonadal dysgenesis, in which both Leydig and Sertoli cell populations are affected, or from impaired secretion or ac tion of either testosterone or AMH. Until now, only Leydig cell function ha s been assessed in children with ambiguous genitalia, by means of testoster one assay. To determine whether serum AMH would help in the diagnosis of intersex cond itions, we assayed serum AMH levels in 107 patients with ambiguous genitali a of various etiologies. In XY patients, AMH was low when the intersex cond ition was caused by abnormal testicular determination (including pure and p artial gonadal dysgenesis) but was normal or elevated in patients with impa ired testosterone secretion, whereas serum testosterone was low in both gro ups. AMH was also elevated during the first year of life and at puberty in intersex states caused by androgen insensitivity. In 46 XX patients with a normal male phenotype or ambiguous genitalia, in whom the diagnosis of fema le pseudohermaphroditism had been excluded, serum AMH levels higher than 75 pmol/L were indicative of the presence of testicular tissue and correlated with the mass of functional testicular parenchyma. In conclusion, serum AMH determination is a powerful tool to assess Sertoli cell function in children with intersex states, and it helps to distinguis h between defects of male sexual differentiation caused by abnormal testicu lar determination and those resulting from isolated impairment of testoster one secretion or action.