THE androgenetic alopecia (AAG), also known as baldness, is one of the main causes of hair loss. It affects both men and women, but its prevalence in females is relatively lower. Despite not causing health risks, it is a problem that affects self-esteem, especially when it affects women.
The genetic causes of baldness are not yet well known, although some theories are proposed to explain it. The oldest of the theories argued that it was an autosomal inheritance that behaved differently between men and women. According to this hypothesis, in men, it behaved as an autosomal dominant; however, in women, it was autosomal recessive.
After several studies, it was concluded that it was a polygenic inheritance, however little is known about which genes are actually involved in baldness. Some studies have shown an increase in the concentration of an androgen receptor and differences in the genes responsible for this receptor. It is noteworthy that this is just one of the genes involved in the AAG development process.
THE baldness it is related to testosterone, which, upon reaching the scalp of individuals with genetic predisposition, undergoes the action of 5-alpha-reductase and is converted into dihydrotestosterone (DHT). This is responsible for the gradual reduction of the hairs, which become shorter, thinner and lighter. This process is called miniaturization.
In men, hair loss usually follows a pattern, usually starting with thinning in the frontal region. After the involvement of this region, baldness settles in the region of the top of the head. It is believed that hair loss happens gradually, with a reduction of about 5% per year. In women, hair loss occurs diffusely, usually on the top of the head.
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The treatments for baldness available nowadays are based on the application of appliqués and grafts, in addition to drug forms. Among the remedies that have proven their effect, we can mention minoxidil and finasteride.
Minoxidil is a drug that works to reduce hair loss and stimulate hair growth, and should be applied to the bald area. After stopping its use, the patient returns to the initial stage and the fall process continues. Finasteride is an oral drug that acts as a hormonal blocker that prevents the transformation of testosterone into DHT. Like minoxidil, it must be used constantly. Finasteride has side effects, the most common being decreased libido and erectile dysfunction.
What we have today are medications that do not cure baldness and only minimize the symptoms presented. Treatments based on graft techniques have good results, but they are surgical methods and, therefore, have their risks. Therefore, there is no miracle cure for genetic baldness, and studies are needed to really clarify its cause so that effective treatments are created.
by Vanessa dos Santos
Graduated in Biology
Would you like to reference this text in a school or academic work? Look:
SANTOS, Vanessa Sardinha dos. "Baldness"; Brazil School. Available in: https://brasilescola.uol.com.br/biologia/genetica-calvicie.htm. Accessed on June 28, 2021.
