In hypergonadotropic hypogonadism, both human and animal data suggest a pathological desensitization of the FSH receptor (FSHR) caused by high circulating levels of gonadotrophins (Gnanaprakasam et al., 1979; Namiki et al., 1985, 1987; Themmen et al., 1991; Foresta et al., 2004). The gene discussed is FSHR; the disease is Hypergonadotropic hypogonadism.