Evaluation of the tubular and interstitial functions of the testis in 46,XY patients with ambiguous genitalia

Investigation of the origin of sexual ambiguity is complex. Although testic ular function has traditionally been assessed only by examining the steroid ogenic capacity of Leydig cells and spermatogenesis, it has recently been s hown that the measurement of serum anti-Mullerian hormone (AMH) as a marker of Sertoli cell function may also help clinicians. The aim of this study w as to evaluate both Leydig and Sertoli cell functions in 46,XY patients wit h intersex states in order to establish biochemical patterns that would hel p to reach an etiologic diagnosis. We measured serum androgens, AMH and gon adotropins in 24 patients with sexual ambiguity and XY karyotype: 8 with go nadal dysgenesis (GD), 3 with 3 beta-hydroxy-steroid dehydrogenase deficien cy (3 beta HSD), 5 with androgen insensitivity syndrome (AIS), 4 with 5 alp ha-reductase 2 (SRD5A2) deficiency, and 4 were of unknown origin or idiopat hic, Our results showed that while testosterone was low and gonadotropins e levated in patients with either GD or 3 beta HSD, AMH was low in the former and high in the latter. Serum AMH and gonadotropins were normal or high in patients with 3 beta HSD or AIS, but these could be distinguished by testo sterone levels. Serum testosterone and gonadotropins were normal or high in AIS and SRD5A2 deficiency patients; however, while AMH was elevated in AIS , it was not the case in SRD5A2 deficiency patients, indicating that testos terone is sufficient to inhibit AMH within the testis. In idiopathic cases gonadotropins and testosterone were normal, and AMH was normal or low. We c onclude that the combined measurement of androgens, AMH and gonadotropins h elps to establish the diagnosis in intersex patients.