Familial male-limited precocious puberty

Familial male-limited precocious puberty (FMPP), also known as testotoxicosis, is a rare genetic disorder characterized by the early onset of puberty in males. This condition is limited to males as it affects the testosterone production in the testes.

Causes

FMPP is caused by mutations in the LHCGR gene, which encodes the luteinizing hormone receptor. This receptor plays a crucial role in sexual development and reproduction. Mutations in the LHCGR gene lead to constant activation of the receptor, resulting in increased testosterone production and early onset of puberty.

Symptoms

The primary symptom of FMPP is the early onset of puberty in males, typically before the age of 9. This includes the development of secondary sexual characteristics such as increased muscle mass, deepening of the voice, and growth of facial and body hair. Other symptoms may include accelerated bone growth and advanced skeletal maturation, leading to short stature in adulthood.

Diagnosis

Diagnosis of FMPP is based on clinical symptoms and confirmed by genetic testing for mutations in the LHCGR gene. Other diagnostic tests may include hormone level testing and bone age studies to assess the rate of skeletal maturation.

Treatment

Treatment for FMPP aims to delay the onset of puberty and slow down the rate of bone maturation. This is typically achieved through the use of medications that block the effects of testosterone. Regular monitoring of growth and development is also important in managing this condition.

Prognosis

With appropriate treatment, the prognosis for individuals with FMPP is generally good. However, without treatment, the condition can lead to short stature in adulthood due to premature closure of the growth plates in the bones.

See also

• Precocious puberty
• Luteinizing hormone
• Testosterone