Understanding the Genetics of Pattern Baldness
Millions of people around the world suffer from pattern baldness. In fact, the condition -- which is formally known as androgenic alopecia is responsible for 95% of all hair loss in men. But men aren't the only ones suffering.
While this condition is typically referred to as "male pattern baldness", women can fall victim to it, too. It's estimated that roughly 55% of women experience minor patterned hair loss as they age, while about 20% of them suffer moderate or severe hair loss.
What does pattern baldness look like?
This condition is easy to spot in men, because it develops in a very specific pattern. The hairline above each of the temples begins to recede, and in the process, it creates an unmistakable "M" shape. At the same time, hair around the crown gets thinner. If left untreated, androgenic alopecia can lead to complete baldness.
In women, though, the pattern isn't as distinct. Instead of losing hair in a specific place, women who suffer from this condition see hair all over their head getting thinner.
When is pattern baldness most likely to occur?
The vast majority of women who develop pattern baldness don't see any symptoms until after menopause. In men, however, pattern baldness can begin at virtually any age. It's estimated that 20% of male sufferers start to see symptoms in their 20's. As men age, though, the condition becomes much more prevalent. By age 50, over 50% of men have suffered some type of hair loss -- whether it's complete baldness, partial baldness, or hair that has simply gotten thinner.
What causes pattern baldness?
Unlike other types of baldness -- which can be caused or worsened by outside factors, like drug treatments and nutritional deficiencies -- androgenic alopecia is caused solely by genetics. Specifically, research has shown that the AR gene is responsible for pattern baldness. How so?
The AR gene is in charge of making androgen receptors -- or, proteins that are built to respond appropriately to dihydrotestosterone (DHT), a byproduct of testosterone. But if there are alterations in the AR gene -- either in the number of DNA building blocks or in the type of DNA building blocks -- hair follicles become extra-sensitive to DHT. If that sensitivity goes untreated long enough, the follicles shrink and, eventually, become unable to produce any new hair.
Back in 2008, scientists learned that the AR gene sits on the X chromosome -- which comes from the mother's side. As a result, men may wind up with a hairline that looks more like their maternal grandfather's than their father's.
However, scientists haven't ruled out genetics on the Y chromosome. Studies have shown that men whose fathers had experienced hair loss were 2.5 times more likely to experience hair loss themselves. And, further research has shown that men whose fathers had experienced hair loss were 2.5 times more likely to experience hair loss themselves, regardless of the mother's side of the family.
Regardless of which chromosomes play a bigger role, it's safe to say that the genetic link to pattern baldness is very strong. It's so strong, in fact, that it's very common to see clumps of close relatives who all suffer from it.
Is androgenic alopecia dangerous?
Pattern baldness itself is harmless. However, studies have linked the condition to a higher risk of heart disease. This link is strongest in men who started losing their hair at a young age.
In women, pattern baldness can be a symptom of higher-than-normal levels of male hormones. As a result, women who suffer from pattern baldness can develop Polycystic Ovary Syndrome (PCOS), a condition in which cysts develop on the ovaries.