Luteinizing hormone insensitivity

Luteinizing hormone insensitivity (LHI), also known as Leydig cell hypoplasia or Leydig cell agenesis, is a rare, autosomal recessive genetic disorder characterized by an insensitivity to luteinizing hormone (LH), a hormone produced by the pituitary gland.

Overview

Luteinizing hormone (LH) is a hormone secreted by the pituitary gland that stimulates the Leydig cells in the testes to produce testosterone. In individuals with LHI, the Leydig cells are insensitive to LH, resulting in low levels of testosterone.

Causes

LHI is caused by mutations in the LHCGR gene, which encodes the luteinizing hormone receptor. This receptor is found on the surface of Leydig cells and is responsible for binding to LH. Mutations in the LHCGR gene can result in a receptor that is unable to bind to LH, leading to insensitivity.

Symptoms

The symptoms of LHI can vary greatly depending on the severity of the condition. In males, symptoms can include cryptorchidism (undescended testes), micropenis, and lack of secondary sexual characteristics. In females, symptoms can include amenorrhea (absence of menstruation) and infertility.

Diagnosis

Diagnosis of LHI is typically made through a combination of physical examination, medical history, and laboratory tests. Laboratory tests may include measurement of hormone levels, genetic testing for mutations in the LHCGR gene, and in some cases, a biopsy of the testes.

Treatment

There is currently no cure for LHI. Treatment is typically focused on managing symptoms and may include hormone replacement therapy with testosterone or estrogen, surgery to correct cryptorchidism, and fertility treatments.

See also

• Luteinizing hormone
• Leydig cells
• Pituitary gland
• Luteinizing hormone/choriogonadotropin receptor