Diseases of the hypothalamus and the pituitary gland

Among males Kallmann syndrome in its fully developed form has a prevalence of about 1 in 10,000. The prevalence in males is four times higher than in females (Seminara et al. 1998). Currently the genetic defect underlying Kallmann syndrome and IHH can be demonstrated in about half of the familial cases and in about 10% of the sporadic cases. The old denomination idio-pathic hypogonadotropic hypogonadism, which reflects ignorance of the causal defect, therefore appears obsolete. The acronym IHH should stand for isolated hypogonadotropic hypogonadism, referring to the inadequacy of gonadotropin secretion as the only defect. © 2010 Springer-Verlag Berlin Heidelberg.