Abstract
Male fetal sexual differentiation of the genitalia is driven by Leydig cell-secreted
androgens and Sertoli cell-secreted anti-Müllerian hormone (AMH). Disorders of sex
development (DSD) may be due to abnormal morphogenesis of genital primordia or to
defective testicular hormone secretion or action. In dysgenetic DSD, due to an early
fetal-onset primary hypogonadism affecting Leydig and Sertoli cells, the fetal gonads
are incapable of producing normal levels of androgens and AMH. In non-dysgenetic DSD,
either Leydig cells or Sertoli cells are affected but not both. Persistent Müllerian
duct syndrome (PMDS) may result from Sertoli cell-specific dysfunction due to mutations
in the AMH gene; these patients have Fallopian tubes and uterus, but male external
genitalia. In DSD due to insensitivity to testicular hormones, fetal Leydig and Sertoli
cell function is normal. Defective androgen action is associated with female or ambiguous
genitalia whereas insensitivity to AMH results in PMDS with normal serum AMH. Clinical
and biological features of PMDS due to mutations in the genes coding for AMH or the
AMH receptor, as well as genetic aspects and clinical management are discussed.
Keywords
testis differentiation - steroidogenesis - ambiguous genitalia