One affected male had an affected son, indicating autosomal dominant inheritance, and in another report, one identical twin had Kallmann's syndrome, while the other was normal. Isolated LH deficiency (the fertile eunuch syndrome) is characterised by adequate FSH secretion and spermatogenesis but by reduced LH secretion and deficient testosterone production. Isolated FSH deficiency due to the deficient production of the b-subunit of FSH has also been documented.
