Familial male-limited precocious puberty is a condition that causes early sexual maturity in males; females are not affected. Boys with this disorder begin exhibiting the signs of puberty in early childhood, between the ages of 2 and 5. Signs of male puberty include a deepening voice, acne, increased body hair, underarm odor, growth of the penis and testes, and spontaneous erections. Changes in behavior, such as increased aggression and early interest in sex, may also occur. Without treatment, affected boys grow quickly at first, but they stop growing earlier than usual. As a result, they tend to be shorter in adulthood compared with other members of their family.

Familial male-limited precocious puberty is a rare disorder; its prevalence is unknown.

Familial male-limited precocious puberty can be caused by mutations in the LHCGR gene. This gene provides instructions for making a receptor protein called the luteinizing hormone/chorionic gonadotropin receptor. Receptor proteins have specific sites into which certain other proteins, called ligands, fit like keys into locks. Together, ligands and their receptors trigger signals that affect cell development and function.

The protein produced from the LHCGR gene acts as a receptor for two ligands: luteinizing hormone and a similar hormone called chorionic gonadotropin. The receptor allows the body to respond appropriately to these hormones. In males, chorionic gonadotropin stimulates the development of cells in the testes called Leydig cells, and luteinizing hormone triggers these cells to produce androgens. Androgens, including testosterone, are the hormones that control male sexual development and reproduction. In females, luteinizing hormone triggers the release of egg cells from the ovaries (ovulation); chorionic gonadotropin is produced during pregnancy and helps maintain conditions necessary for the pregnancy to continue.

Certain LHCGR gene mutations result in a receptor protein that is constantly turned on (constitutively activated), even when not attached (bound) to luteinizing hormone or chorionic gonadotropin. In males, the overactive receptor causes excess production of testosterone, which triggers male sexual development and lead to early puberty in affected individuals. The overactive receptor has no apparent effect on females.

Approximately 18 percent of individuals with familial male-limited precocious puberty have no identified LHCGR gene mutation. In these individuals, the cause of the disorder is unknown.

Genetic Testing Information

• Genetic Testing Registry: Gonadotropin-independent familial sexual precocity

Genetic and Rare Diseases Information Center

• Familial male-limited precocious puberty

Patient Support and Advocacy Resources

• National Organization for Rare Disorders (NORD)

Clinical Trials

• ClinicalTrials.gov

Catalog of Genes and Diseases from OMIM

• PRECOCIOUS PUBERTY, MALE-LIMITED

Scientific Articles on PubMed

• PubMed

• Brito VN, Latronico AC, Arnhold IJ, Mendonca BB. Update on the etiology, diagnosis and therapeutic management of sexual precocity. Arq Bras Endocrinol Metabol. 2008 Feb;52(1):18-31. doi: 10.1590/s0004-27302008000100005. Citation on PubMed
• Chan WY. Disorders of sexual development caused by luteinizing hormone receptor mutations. Beijing Da Xue Xue Bao Yi Xue Ban. 2005 Feb 18;37(1):32-8. Citation on PubMed
• Soriano-Guillen L, Mitchell V, Carel JC, Barbet P, Roger M, Lahlou N. Activating mutations in the luteinizing hormone receptor gene: a human model of non-follicle-stimulating hormone-dependent inhibin production and germ cell maturation. J Clin Endocrinol Metab. 2006 Aug;91(8):3041-7. doi: 10.1210/jc.2005-2564. Epub 2006 May 9. Citation on PubMed
• Themmen AP, Verhoef-Post M. LH receptor defects. Semin Reprod Med. 2002 Aug;20(3):199-204. doi: 10.1055/s-2002-35384. Citation on PubMed
• Traggiai C, Stanhope R. Disorders of pubertal development. Best Pract Res Clin Obstet Gynaecol. 2003 Feb;17(1):41-56. doi: 10.1053/ybeog.2003.0360. Citation on PubMed