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Female pattern baldness is much less predictable than male pattern hair loss, and recent research has shown the genetics and mechanisms to be different. For women, genetic hair thinning, also called androgenetic alopecia, androgenic alopecia, or female pattern baldness, is the most common form of age-related hair loss. In their recent paper “Update on Pathogenesis, Genetics and Medical Treatments of Patterned Hair Loss,“ published in the November 2010 issue of Journal of Drugs in Dermatology, coauthors Dr. Eric Schweiger and Dr. Robert Bernstein reviewed the major advances in the genetics of women's hair loss over the past decade, as well as our understanding of how it is caused. Female pattern hair loss is estimated to affect 21 million women worldwide, most commonly older women. By age 20-30, only 6-12 percent of women experience female pattern hair loss, but by age 70, 40-55 percent of women experience some type of hair thinning. Female pattern hair loss in women increases with age and occurs when more hairs fall out than are replaced by regrowth, although the pattern of thinning is more diffuse (occurring all over the head with no general pattern) than the pattern in men. Female pattern baldness is caused by three factors: genes, hormones & age It was believed that female pattern hair loss was caused by the same mechanism as male pattern hair loss, but recent studies have shown some differences. While women do experience higher levels of the male hormone (androgen) testosterone in the blood stream as they age and estrogen decreases during menopause, testosterone does not convert to the follicle-attacking dihydrotestosterone (DHT), suggesting that the type II 5-alpha-reductase, which commonly occurs in men and increases as they age, is not as important in female pattern hair loss. Clinically, female pattern hair loss presents as a diffuse reduction in hair density affecting the crown and frontal scalp, as shown in the Ludwig Scale system of classification. As in male pattern hair loss, there is an alteration of the hair cycle with a gradual reduction in the duration of the growth phase (anagen) and an increase in the telogen phase between the time a hair is shed and the time a new one grows. Studies show the increase in the telogen phase is parallel to the increase in vellus (very fine) hair production and progressive hair follicle shrinkage. As age and pattern hair loss progress, the number of vellus hairs increases and the follicles continue to shrink, until the hair does not grow back and is lost. The review also found that women with fewer of a particular variant, in the androgen receptor (AR) gene were shown to have an increased risk of developing this type of female pattern hair loss. In women, the AR gene is located on the X chromosome and contains a region encoded by CAG repeats. Research has found that there is an inverse relationship between the number of repeats and AR activity. “If you have fewer CAG repeats, a ‘shorter’ gene than most people, then you have a higher risk of developing androgenic alopecia,“ said Dr. Schweiger. The number of CAG repeats has also been shown to have clinical implications for disease in women such as polycystic ovarian syndrome, hirsutism (excess facial hair) and acne. The diagnosis of androgenetic alopecia, or female pattern hair loss The diagnosis of female pattern hair loss is relatively straightforward when there is a gradual hair thinning in the front and/or top of the scalp, relative preservation of the frontal hairline, a positive family history of hair loss and the presence of miniaturization, which can be observed using a densitometer, a handheld instrument that magnifies a small area of the scalp where the hair has been clipped to about 1 millimeter in length. When the diagnosis of androgenetic alopecia is still uncertain, further diagnostic information can be obtained from a hair-pull test, a scraping and culture for fungus, a microscopic examination of the hair bulb and shaft, and a scalp biopsy. A dermatologic consultation is warranted whenever the cause of hair loss is unclear. Genetic testing may predict female pattern baldness The HairDX genetic screening test, prior to the onset of symptoms, is used to predict whether a woman will experience pattern hair loss. The test is sold to doctors in a kit, is administered by a simple cheek swab and tests for the gene variant, or CAG repeat. The test provides women with a CAG Repeat Score. A smaller number in the CAG test score is associated with a higher risk for significant hair loss (Ludwig grade II or III hair loss), while a larger test score is associated with a lower risk for hair loss. “I think the test has probably identified a predictor of female pattern hair loss, but not the only predictor,” says Dr. Schweiger. “There is science behind the test and some published research studies” . #HairLossWomen #FemaleHairLoss #femalePatternHairLoss #femaleHairLossTreatments #hairThinning #Nikolays
