BIOCHEMICAL SELECTION OF PREPUBERTAL PATIENTS WITH ANDROGEN INSENSITIVITY SYNDROME BY SEX HORMONE-BINDING GLOBULIN RESPONSE TO THE HUMAN CHORIONIC-GONADOTROPIN TEST

Before puberty, the diagnosis of androgen insensitivity syndrome (AIS) can be difficult We studied whether the decrease of sex hormone-bindi ng globulin (SHBG) during the human chorionic gonadotropin (hCG) test may represent a biochemical test to select prepubertal patients with A IS. We examined prepubertal patients with AIS (n = 9, age 0.9-8.2 y), male pseudohermaphroditism not due to AIS (other-MPH) (n = 8, age 0.6- 10.7 y), and control boys (n = 12, age 0.8-12.5 y). Testosterone and S HBG levels (mean +/- SD) were measured before (d 0) and after (d 5) a hCG test (1500 IU x 3 d). Testosterone levels (nmol/L) increased in al l groups [AIS: from 1.5 +/- 1.2 to 22.1 +/- 11.8 (p < 0.001); other-MP H: from 0.6 +/- 0.6 to 9.2 +/- 7.4 (p < 0.02); controls: from 1.8 +/- 1.4 to 22.8 +/- 14.4 (p < 0.001)]. SHBG concentrations (nmol/L) did no t change in AIS [from 66.2 +/- 15.1 to 67.5 +/- 18.6 (p = NS), h-varia tion 1.7 +/- 12.7%], whereas they were significantly decreased in othe r-MPH [from 59.9 +/- 14.2 to 46.5 +/- 18.6 (p < 0.005), Delta-variatio n -23.7 +/- 19.6%] and controls [from 63.0 +/- 16.9 to 33.7 +/- 14.6 ( p < 0.003), Delta-variation -46.9 +/- 15.2%]. Our data suggest that th e SHBG changes during the hCG test can be used to assess in vivo the b iologic response to androgens in prepubertal patients with ambiguous g enitalia, selecting those patients in whom it is worth performing seco nd level investigations to confirm the AIS diagnosis.