AR gene mutation is the most frequent cause of 46,XY DSD, with a clearly higher frequency in the complete phenotype. Mutations spread along the whole coding sequence, including exon 1. This series shows that 60% of mutations detected during the period 2002-2009 were novel.

The postpubertal outcome of a group of girls diagnosed of premature pubarche during childhood was assessed 1) to determine the incidence of functional ovarian hyperandrogenism (FOH) through the ovarian-steroidogenic response to the GnRH agonist leuprolide acetate, 2) to validate leuprolide acetate stimulation in FOH diagnosis, and 3) to ascertain whether FOH-predictive biochemical markers exist at the diagnosis of premature pubarche. Of 35 patients (age, 15.4 +/- 1.5 yr), 16 showed hirsutism, oligomenorrhea, and elevated baseline testosterone and/or androstenedione (delta 4-A) levels. Subcutaneous administration of leuprolide acetate (500 micrograms) produced similar increases in gonadotropin levels in oligomenorrheic patients, regularly menstruating patients (n = 19), and controls (n = 12; age, 15.3 +/- 1.3 yr) when tested at 6 h. Of all of the steroids measured, 17-hydroxyprogesterone (17-OHP) and delta 4-A levels 24 h postleuprolide acetate stimulation were significantly higher in oligomenorrheic patients than in the other two groups (P < 0.0001). No overlapping in 17-OHP responses occurred between oligomenorrheic patients and the other groups. Baseline dehydroepiandrosterone sulfate and delta 4-A levels at the diagnosis of premature pubarche correlated with 17-OHP values postleuprolide acetate challenge (r = 0.47; P < 0.005 and r = 0.67; P < 0.0001, respectively). These results show a distinct leuprolide acetate challenge response in 45% of the postpubertal premature pubarche girls studied, suggestive of an increased incidence of FOH, and support the need for continued routine postmenarcheal evaluation of this group of patients. Responses of 17-OHP to leuprolide acetate challenge facilitate the identification of FOH patients, establish this test as a reliable diagnostic tool in FOH diagnosis, and confirm the ovaries as the source of hyperandrogenemia in most patients with androgen excess. Although increased 17-OHP responses after leuprolide acetate stimulation seem to occur more frequently in girls with elevated dehydroepiandrosterone sulfate and/or delta 4-A levels at the diagnosis of premature pubarche, specific biochemical markers predictive of FOH in this group of patients are still lacking.

These results are concordant with the phenotype of the two sisters studied and demonstrate a differential role for TTF1 in the different tissues in which it is expressed.