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Genetics Home Reference: your guide to understanding genetic conditions
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Androgenetic alopecia

Reviewed May 2006

What is androgenetic alopecia?

Androgenetic alopecia is a common form of hair loss in both men and women. In men, this condition is also known as male-pattern baldness. Hair is lost in a well-defined pattern, beginning above both temples. Over time, the hairline recedes to form a characteristic "M" shape. Hair also thins at the crown (near the top of the head), often progressing to partial or complete baldness.

The pattern of hair loss in women differs from male-pattern baldness. In women, the hair becomes thinner all over the head, and the hairline does not recede. Androgenetic alopecia in women rarely leads to total baldness.

Androgenetic alopecia in men has been associated with several other medical conditions including coronary heart disease and enlargement of the prostate, a walnut-sized gland in males that is located below the bladder. Additionally, prostate cancer, disorders of insulin resistance (such as diabetes and obesity), and high blood pressure (hypertension) have been related to androgenetic alopecia. In women, androgenetic alopecia is associated with an increased risk of polycystic ovary syndrome (PCOS). PCOS is characterized by a hormonal imbalance that can lead to irregular menstruation, acne, excess body hair (hirsutism), and weight gain.

How common is androgenetic alopecia?

Although androgenetic alopecia is a frequent cause of hair loss in both men and women, it is more common in men. This form of hair loss affects an estimated 35 million men in the United States. Androgenetic alopecia can start as early as a person's teens and risk increases with age; more than 50 percent of men over age 50 have some degree of hair loss. In women, hair loss is most likely after menopause.

What genes are related to androgenetic alopecia?

The AR gene is associated with androgenetic alopecia.

A variety of genetic and environmental factors likely play a role in causing androgenetic alopecia. Although researchers are studying risk factors that may contribute to this condition, most of these factors remain unknown. Researchers have determined that this form of hair loss is related to hormones called androgens, particularly an androgen called dihydrotestosterone. Androgens are important for normal male sexual development before birth and during puberty. Androgens also have other important functions in both males and females, such as regulating hair growth and sex drive.

Hair growth begins under the skin in structures called follicles. Each strand of hair normally grows for 2 to 6 years, goes into a resting phase for several months, and then falls out. The cycle starts over when the follicle begins growing a new hair. Increased levels of androgens in hair follicles can lead to a shorter cycle of hair growth and the growth of shorter and thinner strands of hair. Additionally, there is a delay in the growth of new hair to replace strands that are shed.

Although researchers suspect that several genes play a role in androgenetic alopecia, variations in only one gene, AR, have been identified in people with this condition. The AR gene provides instructions for making a protein called an androgen receptor. Androgen receptors allow the body to respond appropriately to dihydrotestosterone and other androgens. Studies suggest that variations in the AR gene lead to increased activity of androgen receptors in hair follicles. It remains unclear, however, how these genetic changes increase the risk of patterned hair loss in men and women with androgenetic alopecia.

Researchers continue to investigate the connection between androgenetic alopecia and other medical conditions, such as coronary heart disease and prostate cancer in men and polycystic ovary syndrome in women. They believe that some of these disorders may be associated with elevated androgen levels, which may help explain why they tend to occur with androgen-related hair loss. Other hormonal, environmental, and genetic factors that have not been identified also may be involved.

Related Gene(s)

Changes in this gene are associated with androgenetic alopecia.

  • AR

How do people inherit androgenetic alopecia?

The inheritance pattern of androgenetic alopecia is unclear because many genetic and environmental factors are likely to be involved. This condition tends to cluster in families, however, and having a close relative with patterned hair loss appears to be a risk factor for developing the condition.

Where can I find information about diagnosis or management of androgenetic alopecia?

These resources address the diagnosis or management of androgenetic alopecia and may include treatment providers.

  • Genetic Testing Registry: Baldness, male pattern (http://www.ncbi.nlm.nih.gov/gtr/conditions/C0162311)
  • MedlinePlus Encyclopedia: Female Pattern Baldness (http://www.nlm.nih.gov/medlineplus/ency/article/001173.htm)
  • MedlinePlus Encyclopedia: Hair Loss (http://www.nlm.nih.gov/medlineplus/ency/article/003246.htm)
  • MedlinePlus Encyclopedia: Male Pattern Baldness (http://www.nlm.nih.gov/medlineplus/ency/article/001177.htm)

You might also find information on the diagnosis or management of androgenetic alopecia in Educational resources (http://www.ghr.nlm.nih.gov/condition/androgenetic-alopecia/show/Educational+resources) and Patient support (http://www.ghr.nlm.nih.gov/condition/androgenetic-alopecia/show/Patient+support).

General information about the diagnosis (http://ghr.nlm.nih.gov/handbook/consult/diagnosis) and management (http://ghr.nlm.nih.gov/handbook/consult/treatment) of genetic conditions is available in the Handbook. Read more about genetic testing (http://ghr.nlm.nih.gov/handbook/testing), particularly the difference between clinical tests and research tests (http://ghr.nlm.nih.gov/handbook/testing/researchtesting).

To locate a healthcare provider, see How can I find a genetics professional in my area? (http://ghr.nlm.nih.gov/handbook/consult/findingprofessional) in the Handbook.

Where can I find additional information about androgenetic alopecia?

You may find the following resources about androgenetic alopecia 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 androgenetic alopecia?

  • Androgenic alopecia
  • female pattern baldness
  • Male Pattern Alopecia
  • Male Pattern Baldness
  • Pattern baldness

For more information about naming genetic conditions, see the Genetics Home Reference Condition Naming Guidelines (http://ghr.nlm.nih.gov/ConditionNameGuide) and How are genetic conditions and genes named? (http://ghr.nlm.nih.gov/handbook/mutationsanddisorders/naming) in the Handbook.

What if I still have specific questions about androgenetic alopecia?

Ask the Genetic and Rare Diseases Information Center (http://rarediseases.info.nih.gov/GARD/).

What glossary definitions help with understanding androgenetic alopecia?

acne ; alopecia ; androgens ; cancer ; coronary ; coronary heart disease ; diabetes ; dihydrotestosterone ; gene ; hirsutism ; hypertension ; inheritance ; inheritance pattern ; insulin ; insulin resistance ; menopause ; menstruation ; ovary ; polycystic ovary syndrome ; prostate ; protein ; puberty ; receptor ; risk factors ; syndrome

You may find definitions for these and many other terms in the Genetics Home Reference Glossary (http://www.ghr.nlm.nih.gov/glossary).

References

  • Cela E, Robertson C, Rush K, Kousta E, White DM, Wilson H, Lyons G, Kingsley P, McCarthy MI, Franks S. Prevalence of polycystic ovaries in women with androgenic alopecia. Eur J Endocrinol. 2003 Nov;149(5):439-42. (http://www.ncbi.nlm.nih.gov/pubmed/14585091?dopt=Abstract)
  • Chumlea WC, Rhodes T, Girman CJ, Johnson-Levonas A, Lilly FR, Wu R, Guo SS. Family history and risk of hair loss. Dermatology. 2004;209(1):33-9. (http://www.ncbi.nlm.nih.gov/pubmed/15237265?dopt=Abstract)
  • Ellis JA, Stebbing M, Harrap SB. Polymorphism of the androgen receptor gene is associated with male pattern baldness. J Invest Dermatol. 2001 Mar;116(3):452-5. (http://www.ncbi.nlm.nih.gov/pubmed/11231320?dopt=Abstract)
  • Hawk E, Breslow RA, Graubard BI. Male pattern baldness and clinical prostate cancer in the epidemiologic follow-up of the first National Health and Nutrition Examination Survey. Cancer Epidemiol Biomarkers Prev. 2000 May;9(5):523-7. (http://www.ncbi.nlm.nih.gov/pubmed/10815699?dopt=Abstract)
  • Hillmer AM, Hanneken S, Ritzmann S, Becker T, Freudenberg J, Brockschmidt FF, Flaquer A, Freudenberg-Hua Y, Jamra RA, Metzen C, Heyn U, Schweiger N, Betz RC, Blaumeiser B, Hampe J, Schreiber S, Schulze TG, Hennies HC, Schumacher J, Propping P, Ruzicka T, Cichon S, Wienker TF, Kruse R, Nothen MM. Genetic variation in the human androgen receptor gene is the major determinant of common early-onset androgenetic alopecia. Am J Hum Genet. 2005 Jul;77(1):140-8. Epub 2005 May 18. (http://www.ncbi.nlm.nih.gov/pubmed/15902657?dopt=Abstract)
  • Levy-Nissenbaum E, Bar-Natan M, Frydman M, Pras E. Confirmation of the association between male pattern baldness and the androgen receptor gene. Eur J Dermatol. 2005 Sep-Oct;15(5):339-40. (http://www.ncbi.nlm.nih.gov/pubmed/16172040?dopt=Abstract)
  • Lotufo PA, Chae CU, Ajani UA, Hennekens CH, Manson JE. Male pattern baldness and coronary heart disease: the Physicians' Health Study. Arch Intern Med. 2000 Jan 24;160(2):165-71. (http://www.ncbi.nlm.nih.gov/pubmed/10647754?dopt=Abstract)
  • Matilainen V, Koskela P, Keinänen-Kiukaanniemi S. Early androgenetic alopecia as a marker of insulin resistance. Lancet. 2000 Sep 30;356(9236):1165-6. (http://www.ncbi.nlm.nih.gov/pubmed/11030300?dopt=Abstract)
  • Matilainen VA, Mäkinen PK, Keinänen-Kiukaanniemi SM. Early onset of androgenetic alopecia associated with early severe coronary heart disease: a population-based, case-control study. J Cardiovasc Risk. 2001 Jun;8(3):147-51. (http://www.ncbi.nlm.nih.gov/pubmed/11455846?dopt=Abstract)
  • Nyholt DR, Gillespie NA, Heath AC, Martin NG. Genetic basis of male pattern baldness. J Invest Dermatol. 2003 Dec;121(6):1561-4. (http://www.ncbi.nlm.nih.gov/pubmed/14675213?dopt=Abstract)
  • Oh BR, Kim SJ, Moon JD, Kim HN, Kwon DD, Won YH, Ryu SB, Park YI. Association of benign prostatic hyperplasia with male pattern baldness. Urology. 1998 May;51(5):744-8. (http://www.ncbi.nlm.nih.gov/pubmed/9610587?dopt=Abstract)

 

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? (http://ghr.nlm.nih.gov/handbook/consult/findingprofessional) in the Handbook.

 
Reviewed: May 2006
Published: October 20, 2014