User:Mr. Ibrahem/Kallmann syndrome

Kallmann syndrome (KS) is a genetic disorder that results in a decreased sense of smell and a lack of sexual development. People may also have hearing loss, teeth abnormalities, and poorly developed kidneys. Other symptoms may include undescended testicles and a small penis in males. Without treatment complications may include osteoporosis, infertility, and sexual dysfunction.

A variety of genetic mutations can cause KS. Often this occurs spontaneously but some cases may be inherited from a person's parents. Inheritance may be X-linked recessive, autosomal dominant, or autosomal recessive. The underlying mechanism is a failure to produce gonadotropin-releasing hormone, resulting in low testosterone in males and estrogen and progesterone in females. It is a form of hypogonadotropic hypogonadism. Diagnosis often occurs when puberty fails to start and is confirmed by testing hormone levels or genetic testing.

Treatment is generally with hormone replacement therapy (HRT). This may include testosterone or estrogen and progesterone. Gonadotropin may be used to support fertility. In and of itself, it does not result in a lowered life expectancy, though associated complications may.

Kallmann syndrome affects about 1 in 30,000 males and 1 in 120,000 females. The link between loss of smell and small testicles was first described in 1856 by Spanish doctor Aureliano Maestre de San Juan. It was described more fully in 1944 by Franz Josef Kallmann, a German-American geneticist after who it is named.