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Disease Profile


Prevalence estimates on Rare Medical Network websites are calculated based on data available from numerous sources, including US and European government statistics, the NIH, Orphanet, and published epidemiologic studies. Rare disease population data is recognized to be highly variable, and based on a wide variety of source data and methodologies, so the prevalence data on this site should be assumed to be estimated and cannot be considered to be absolutely correct.

<1 / 1 000 000

US Estimated

Europe Estimated

Age of onset






Autosomal dominant A pathogenic variant in only one gene copy in each cell is sufficient to cause an autosomal dominant disease.


Autosomal recessive Pathogenic variants in both copies of each gene of the chromosome are needed to cause an autosomal recessive disease and observe the mutant phenotype.


dominant X-linked dominant inheritance, sometimes referred to as X-linked dominance, is a mode of genetic inheritance by which a dominant gene is carried on the X chromosome.


recessive Pathogenic variants in both copies of a gene on the X chromosome cause an X-linked recessive disorder.


Mitochondrial or multigenic Mitochondrial genetic disorders can be caused by changes (mutations) in either the mitochondrial DNA or nuclear DNA that lead to dysfunction of the mitochondria and inadequate production of energy.

Multigenic or multifactor Inheritance involving many factors, of which at least one is genetic but none is of overwhelming importance, as in the causation of a disease by multiple genetic and environmental factors.


Not applicable


Other names (AKA)

Precocious puberty, male limited; Sexual precocity, familial, gonadotropin-independent; Pubertas Praecox;


Congenital and Genetic Diseases; Endocrine Diseases


Testotoxicosis is a form of gonadotropin-independent precocious puberty in which boys experience early onset and progression of puberty. The disease generally presents between 2 and 4 years of age. Patients have accelerated growth, early development of secondary sexual characteristics and reduced adult height. Testotoxicosis is caused by an activating mutation of the luteinizing hormone receptor (LHCGR) gene, which leads to increased levels of sex steroids in the context of low luteinizing hormone. The condition may be sporadic or transmitted as a dominant trait. It is only expressed in males.[1][2][3][4] Treatment consists of reducing hyperandrogenism in children (sexual maturation, stature), with ketoconazole or a combination of antiandrogens and aromatase inhibitors.[4]


This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

Medical Terms Other Names
Learn More:
80%-99% of people have these symptoms
Accelerated skeletal maturation
Advanced bone age
Early bone maturation

[ more ]

Male infertility
Precocious puberty
Early onset of puberty
Early puberty

[ more ]

Tall stature
Increased body height
30%-79% of people have these symptoms
Abnormal hair morphology
Abnormality of the hair
Hair abnormality

[ more ]

Long penis
Enlarged penis
5%-29% of people have these symptoms
Attention deficit hyperactivity disorder
Attention deficit
Attention deficit disorder
Attention deficit-hyperactivity disorder
Attention deficits
Childhood attention deficit/hyperactivity disorder

[ more ]

Large testis
Low sperm count
Percent of people who have these symptoms is not available through HPO
Decreased testicular size
Small testes
Small testis

[ more ]

Precocious puberty in males
Early onset of puberty in males
Sex-limited autosomal dominant


Decisions regarding treatment for patients with testotoxicosis are complex.[3] Treatment typically consists of reducing hyperandrogenism in children (sexual maturation, stature) with ketoconazole or a combination of antiandrogens and aromatase inhibitors.[3][4] Recently, the use of combination therapy with bicalutamide (a potent antiandrogen agent) and anastrozole or letrozole (third-generation aromatase inhibitors) was reported to yield encouraging short-term results, including slower growth rate.[5][6]

Learn more

These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

Where to Start

In-Depth Information

  • Medscape Reference provides information on this topic. You may need to register to view the medical textbook, but registration is free.
  • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
  • Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 
  • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
  • PubMed is a searchable database of medical literature and lists journal articles that discuss Testotoxicosis. Click on the link to view a sample search on this topic.


  1. Reiter EO, Norjavaara E.. Testotoxicosis: current viewpoint. Pediatr Endocrinol Rev. 2005; https://www.ncbi.nlm.nih.gov/pubmed?term=16361981. Accessed 2/29/2012.
  2. Brito VN, Latronico AC, Arnhold IJ, Mendonca BB. Update on the etiology, diagnosis and therapeutic management of sexual precocity. Arq Bras Endocrinol Metabol. 2008; https://www.scielo.br/scielo.php?script=sci_arttext&pid=S0004-27302008000100005&lng=en&nrm=iso&tlng=en. Accessed 2/29/2012.
  3. Ferry RJ, Fenton CL, Poth MPM. Precocious Pseudopuberty. eMedicine. 2009; https://emedicine.medscape.com/article/923876-overview. Accessed 2/29/2012.
  4. Carel JC. Testotoxicosis. Orphanet. 2005; https://www.orpha.net/consor/cgi-bin/OC_Exp.php?lng=EN&Expert=3000. Accessed 2/29/2012.
  5. Lenz AM, Shulman D, Eugster EA, Rahhal S, Fuqua JS, Pescovitz OH, Lewis KA. Bicalutamide and third-generation aromatase inhibitors in testotoxicosis. Pediatrics. 2010; https://www.ncbi.nlm.nih.gov/pubmed/20713483. Accessed 2/29/2012.
  6. Reiter EO, Mauras N, McCormick K, Kulshreshtha B, Amrhein J, De Luca F, O'Brien S, Armstrong J, Melezinkova H. Bicalutamide plus anastrozole for the treatment of gonadotropin-independent precocious puberty in boys with testotoxicosis: a phase II, open-label pilot study (BATT). J Pediatr Endocrinol Metab. 2010; https://www.ncbi.nlm.nih.gov/pubmed/21158211. Accessed 2/29/2012.

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