Mutations in the human LHCGR gene that is expressed in the testis and ovary lead to disorders of the development of the male secondary sexual character, including familial male precocious puberty, also known as testotoxicosis, hypogonadotropic hypogonadism, Leydig cell adenoma with precocious puberty, and male pseudohermaphroditism with Leydig cell hypoplasia (OMIM 152790). The gene discussed is LHCGR; the disease is Leydig cell hypoplasia.