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Familial male-limited precocious puberty
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Reviewed August 2012
What is familial male-limited precocious puberty?
Familial male-limited precocious puberty is a condition that causes early sexual development 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.
How common is familial male-limited precocious puberty?
Familial male-limited precocious puberty is a rare disorder; its prevalence is unknown.
What genes are related to familial male-limited precocious puberty?
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.
Read more about the LHCGR gene.
How do people inherit familial male-limited precocious puberty?
This condition is inherited in an autosomal dominant, male-limited pattern, which means one copy of the altered LHCGR gene in each cell is sufficient to cause the disorder in males. Females with mutations associated with familial male-limited precocious puberty appear to be unaffected. In some cases, an affected male inherits the mutation from either his mother or his father. Other cases result from new mutations in the gene and occur in males with no history of the disorder in their family.
Where can I find information about diagnosis or management of familial male-limited precocious puberty?
These resources address the diagnosis or management of familial male-limited precocious puberty and may include treatment providers.
General information about the diagnosis and management of genetic conditions is available in the Handbook. Read more about genetic testing, particularly the difference between clinical tests and research tests.
To locate a healthcare provider, see How can I find a genetics professional in my area? in the Handbook.
Where can I find additional information about familial male-limited precocious puberty?
You may find the following resources about familial male-limited precocious puberty helpful. These materials are written for the general public.
You may also be interested in these resources, which are designed for healthcare professionals and researchers.
What other names do people use for familial male-limited precocious puberty?
What if I still have specific questions about familial male-limited precocious puberty?
Where can I find general information about genetic conditions?
The Handbook provides basic information about genetics in clear language.
These links provide additional genetics resources that may be useful.
What glossary definitions help with understanding familial male-limited precocious puberty?
acne ; androgens ; autosomal ; autosomal dominant ; cell ; egg ; familial ; gene ; His ; hormone ; inherited ; mutation ; prevalence ; protein ; puberty ; receptor ; reproduction ; spontaneous ; testes ; testosterone
You may find definitions for these and many other terms in the Genetics Home Reference Glossary.
See also Understanding Medical Terminology.
References (5 links)
The resources on this site should not be used as a substitute for professional medical care or advice. Users seeking information about a personal genetic disease, syndrome, or condition should consult with a qualified healthcare professional. See How can I find a genetics professional in my area? in the Handbook.