If you’re new to Quora, the question and answer website that rapidly seems to have trumped Yahoo Answers, you’ll be thrilled to hear it’s all brilliantly simple. People post a question that they’d like an answer to, and anyone from random people with an opinion to world-famous experts can post a reply, with the best answers quickly “up-voted”. While there are plenty of queries about Beyoncé, NASA and conspiracy theories, there are also some interesting entries about hair loss
One of the best threads is based around the question “What are the genetics of Male Pattern Baldness
?” While it might only have garnered just two replies to date, one of these has attracted more than 4,000 views. And the fact that the answer comes from Adriana Heguy, who says she has “worked in genetics and genomics for the past two decades” probably helps.
The first thing that Ms Heguy does is caution how complex the science behind all this is. She also admits that “the genetics of Androgenetic Alopecia
(genetic baldness) is not really well understood.” Acknowledging that genetic baldness is a 'highly heritable' condition, so is most likely to be passed on through families, she does go on to explain that there is further evidence that non-genetic factors also play a part. Although she does not elaborate on these, this is likely a reference to issues which can exacerbate or trigger hair loss, such as stress
, illness or dietary imbalances
Of the specific genes thought to play a part in Male Pattern Baldness, Ms Heguy first mentions the androgen receptor (AR) gene. She points out that because this receptor is on the X chromosome which is inherited from your mother the myth persists that men need only look at the maternal line of their family tree to see if they’re likely to go bald or not.
“But it (AR) is not the only gene involved,” Ms Heguy explains, “or even the main gene. There are genes in basically all chromosomes that have been implicated in Androgenetic Alopecia, and this is what makes it so difficult to unravel.”
This fits researchers' findings
that it is, in fact, more likely any actively expressed genetic traits are likely to come from our father's side of the family - including hair loss. People are able to carry the genes for androgenetic alopecia without displaying any of the signs if these genes lie dormant and are not active, which can explain why sometimes hair loss appears to 'skip' a generation
DHT inhibits hair growth
Androgen receptors are also known as NR3C4 - which stands for Nuclear Receptor subfamily 3, group C, member 4 - and they control cell behaviour. When testosterone reacts with the enzyme 5-alpha-reductase in a cell, it is converted into the androgen dihydrotestone (DHT
) and, as those with an inherited predisposition to male pattern baldness have an innate sensitivity to DHT, the hair miniaturisation process starts.
Male Pattern Baldness begins when the DHT gradually impedes hair growth by binding to the androgen receptors in the hair follicle and causing increasingly thinning hair
, then eventually stops them from producing hair altogether. For this reason, treatment of Male Pattern Baldness can involve use of a clinically-proven drug, finasteride 1mg
, which inhibits the production of DHT.
A second product, the topical hair loss solution high strength minoxidil
helps to accelerate hair growth and has been seen to be particularly useful when treating stubborn areas such as a receding hairline
Both these MHRA licensed and FDA approved treatments can be used alone or in combination; supplementary hair growth supporting products
can also be added in to a customised course alongside them, as appropriate.
While Ms Heguy admits that we are still far from a definitive “cure” for Androgenetic Alopecia by which she presumably means a single-dose, one-off medication that will completely stop MPB before it has even started she does offer some hope to men who have already lost their hair to the condition: “If there is any consolation for men distressed about hair loss
, if it was a phenotype that was repulsive to females, the gene variants would have been weeded out a long time ago, by sexual selection. Many of us find bald heads very manly and attractive.”