In 30 seconds…
Male Pattern Baldness (MPB) is the most common cause of hair loss. Whether or not you experience this hair loss pattern depends on your genetics.
The belief that you inherit the “baldness gene” from your mother’s side isn’t completely correct. You can inherit characteristics that cause MPB from either parent, and there are many genes that can code for it.
It’s not all bad news: even if baldness runs in your family, there are ways you can “override” the process that causes hair loss.
Noticing your hair thinning or hairline receding is an all-too-relatable experience for many men — and as we get older, more and more of us are likely to encounter it.
What you may not realise, however, is that this particular type of hair loss is decided by your genetics. You can, in fact, inherit hair loss, and not just from your mother’s side.
Another common name for MPB? Hereditary-pattern baldness.
In this article, we’ll look at the science behind what causes MPB, the role your genes play, and the steps you can take to stop hair loss in its tracks.
How Does Hair Loss Happen?
Before we dig into genetics, it helps to understand the biophysical process behind MPB — i.e, what’s actually going on in your scalp that causes hair loss.
Your hair is made in hair follicles, which are pockets of skin that surround the bottom of the hair shaft. People with MPB have smaller hair follicles on their scalp, which is caused by an increased sensitivity to dihydrotestosterone (DHT).
DHT is a more potent form of testosterone (i.e. the male sex hormone) and it comes from testosterone that’s been converted by an enzyme called 5α-reductase. In MPB, this binds to receptors in your hair follicles, causing them to shrink (a process called ‘miniaturization’) so they stop producing healthy hair. Over time, with increased exposure to DHT, the hair follicle can become damaged beyond repair, meaning it’ll lose the ability to make hair altogether.
However, it’s not all doom and gloom: you can stop DHT in its tracks, as we’ll discover below.
Does Hair Loss Come from Your Mother’s Side?
It’s not all your mum’s fault. But the commonly-held belief that the ‘baldness gene’ comes from your maternal grandfather isn’t completely bogus, either.
One of the more well-known genes associated with hair loss is the Androgen Receptor (AR) gene. The AR gene codes for the androgen receptor protein, which helps hair follicles detect androgen hormones (such as DHT). The AR gene is located on the X chromosome. Biological males have both an X and a Y chromosome, while biological females have two X chromosomes. This means you have to inherit your Y from your dad, and your X from your mum — so if you have an X chromosome with a mutant form of the AR gene, you have your mum’s side of the family to thank.
However, inheriting a mutant AR gene doesn’t account for every case of MPB. In fact, it’s now understood to explain little of MPB’s heritability. Yes, your maternal grandfather might have been as bald as a bowling ball, but there’s a strong chance there were other genes responsible for his hair loss, which you may or may not inherit. In the same vein, different genes you inherit from your dad could also have a part to play in whether you experience MPB.
How Else Can You Get Male Pattern Baldness?
No need to fear contagions just yet: MPB is still understood to be hereditary, but a recent study into MPB indicates that, rather than it being a singular mutation in the AR gene, MPB is a polygenic condition, meaning there are several genetic variants (or mutations) that could be responsible.
Studies that examined the whole genome in relation to MPB found that one in seven men have variants on chromosome 20 that are risk factors for hereditary-pattern baldness. Chromosome 20 and the X Chromosome are completely separate entities, meaning you could inherit it from either parent. One particular variant on Chromosome 20, called rs1160312 (catchy name, we know) is especially associated with androgenic alopecia in men, increasing their likelihood of experiencing MPB by 60%.
That’s not all. More studies indicate that MPB could be down to a cluster of genetic variants, with each additional mutation you inherit increasing your risk of going bald. One study identified 63 genome-wide loci that contribute towards MPB, while another identified 71. These genes code for a range of characteristics, from how sensitive you are to testosterone, to whether your body can de-pigmatise hair.
Furthermore, inheriting these variants has been found to be more predictive of developing MPB than the mutation in the X chromosome.
How Do I Prevent Hereditary Hair Loss?
Unfortunately, you can’t undo your genetics. Androgenetic alopecia (MPB) is highly heritable, with research estimating heritability of over 80%, meaning if someone in your family has MPB, there’s a strong chance you’ll inherit the genes for it, too.
However, modern scientific understanding of the biophysical process causing balding has led to effective treatments that can stop the triggers for MPB, even if you are genetically predisposed to it.
In English? Remember our old “friend” DHT — i.e. the trigger for hair follicle miniaturization? If you suppress the enzyme that turns testosterone into DHT, you can prevent it from causing the chain reaction that results in you losing your hair.
Finasteride (sometimes known by the brand name Propecia) is in a class of medications called 5-alpha reductase inhibitors, which means it blocks the exact hormone responsible for DHT. It comes as an oral tablet to take once a day. Where your hair follicles have started miniaturizing, it’ll prevent the condition from worsening and can help them return to full health.
This means that your hair loss will stop and, in many cases, you’ll see hair regrowth and hair restoration.
The results speak for themselves: in clinical trials, 90% of men reported halted hair loss, and 70% of men even saw new hair. And 98.6% of men experienced no side effects.
Furthermore, combining Finasteride with a topical spray such as Minoxidil (brand-name Regaine) that encourages blood flow to the scalp can help boost results further.
The clue’s in the name: hereditary-pattern hair loss is down to genetics.
But if you’re worried about losing your hair because your maternal grandfather was bald, it’s worth noting that it’s not as simple as that. There are plenty of genetic variants that could cause you to develop MPB, and it doesn’t necessarily have to come from your mum.
Of course, knowing there are even more reasons you could experience MPB is less than comforting. And at present, there’s nothing you can do to ‘undo’ those genetics. However, there are still steps you can take to avoid losing your hair. Some men opt for expensive (and painful) hair transplants, while others embrace the baldness. But it’s helpful to know that there’s a third, scientifically proven, option out there in the form of Finasteride.