> Hair Loss/Baldness

• Alternative Names
• Symptoms & Characteristics
• Treatment
• How Common Is It?
• Genetics & Inheritance
• Genetic Testing
• Support & More Information

Alternative Names

Hair loss; Baldness; Male Pattern Baldness; Pattern Baldness

Symptoms & Characteristics

Alopecia is the medical description of the involuntary loss of hair from the head or body, which may lead to baldness. Some common causes of hair loss include (but are not limited to):

• some diseases, such as thyroid/hormonal problems, heart disease, hypertension, diabetes or lupus

• some medications, radiation or chemotherapy for cancer

• low protein diet or poor nutrition

• ringworm of the scalp

• stress or nervous habits like hair pulling and scalp rubbing

• tumors of the ovaries or adrenal glands

• excessive shampooing or hair blowing

Androgenetic alopecia (AA) is a common form of hereditary hair loss in both men and women. AA appears to be caused by a combination of genetics, age and androgen (like testosterone) levels.

• In males, this condition is also known as male-pattern baldness, and the hair loss occurs in a well-defined pattern. The hair loss begins above both temples and recedes to form a characteristic "M" shape. The hair also thins at the crown (near the top of the head), which can lead to baldness. Also in males, androgenetic alopecia has also been associated with other health conditions like heart disease, prostate enlargement, disorders of insulin resistance (such as diabetes and obesity), and high blood pressure (called hypertension).
  
  
• In females, the hair loss pattern differs. The hair becomes thinner all over the scalp and the hairline does not recede. Also in females, androgenetic alopecia has also been associated with an increased risk to develop polycystic ovary syndrome (PCOS). PCOS is characterized as an hormonal imbalance that result in irregular menstruation, acne, excess body hair (called hirsutism), and weight gain.

Alopecia areata is another condition that can also lead to hair loss. Alopecia Areata is an autoimmune condition in which the body attacks the hair cells and stops growth. The hair loss occurs in patches from areas of the body, usually from the scalp. In 1% to 2% of cases, the condition can spread to the entire scalp (called alopecia totalis) or over the whole body (called alopecia universalis).

Treatment

There is no cure for androgenetic alopecia or alopecia areata.

• In androgenetic alopecia, treatment is focused on preventing further hair loss.

• In alopecia areata, a combination of treatments is typically the best approach. Treatment also depends on the severity of hair loss.

How Common Is It?

Androgenetic alopecia is very common and affects approximately 50% of men older than 40 years old. AA increases in women following menopause. Approximately 75% of women older than 65 years old may be affected. The incidence and the severity is highest in Caucasian males, then African-Americans and Asians. AA is least common in Native Americans.

Alopecia areata affects 1% to 2% of people, both males and females alike.

Genetics & Inheritance

Androgenetic alopecia and alopecia areata are multifactorial conditions, which means they involve a combination of genetic, lifestyle and environmental factors.

• Variations in one gene, called the AR gene, on the X chromosome at the location 11.2-q12 appear to be associated with an increased risk (or susceptibility) to develop androgenetic alopecia.

• Two areas on chromosomes 16 and 18 have been linked to susceptibility to alopecia areata. Other yet to be classified or adequately classified genes are also likely to be involved.

Genetic Testing

Clinical genetic testing for alopecia areata is available on a research basis only. Clinical genetic testing for androgenetic alopecia is unavailable.

For more information on the genetics of alopecia, the benefits and limitations of genetic testing, accurate diagnosis, and recurrence risk; use our find a genetic professional directory to locate a trained genetic professional in your area.

• A medical geneticist can also be found at the American College of Medical Genetics website.

• A genetic counselor can also be found at the National Society of Genetic Counselors website.

Informational genetic testing for susceptibility to androgenetic alopecia is available online (over the internet). In addition, informational genetic testing for susceptibility to androgenetic alopecia or alopecia areata is also available as part of a whole genome scan. Whole genome scanning involves analyzing thousands of SNPs at once related to a number of different health conditions.

• At this point, many genetic professionals do not consider this testing clinically useful or medically relevant, but for informational purposes only. Go to the Tests tab to link to the best providers, compare providers and read provider reviews.

Support & More Information

More information can be found at:

• Androgenetic Alopecia - Genetics Home Reference

Support can be found at:

• Alopecia Areata - The National Alopecia Areata Foundation