Male Pattern Baldness

Baldness

Extensive research has shown that whether or not you will go bald, as well as the patterns of baldness, are strongly affected by genetics.

Baldness is far more common in men, so this article focuses on male pattern baldness - we will cover baldness in females in an upcoming report!

A study of 50,000+ men in the UK (with an average age of 57) found that more than 70% had some hair loss, and about 20% had severe hair loss [1] Jump to reference section: [1] .

This study and many others have examined the role our genetics play in determining our susceptibility to hair loss and many have found it to be highly influential.

Another study looked at 70,000 men and estimated the heritability of male pattern baldness to be 80%, while identifying 71 different genetic variants that impact male pattern baldness risk. Together these genetic variants accounted for nearly 38% of the risk [2] Jump to reference section: [2] .

Hundreds of genetic variants have been suggested to influence a person’s likelihood of baldness, with varying degrees of evidence. This article covers three genetic variants with a high impact on the likelihood of baldness as well as having a high degree of evidence from multiple research groups.

The first gene ever associated with baldness through genetics studies was the Androgen Receptor gene (AR). As the name implies, the AR gene encodes for a protein receptor for several of the hormones typically involved in male development and sexuality, such as testosterone.

A small change in the AR sequence can have a large effect. People who carry an ‘A’ at rs2497911 are about 2.5x more likely to have baldness. About 20% of men have an ‘A’ at rs2497911, while 80% have a ‘C’, which does not add extra risk.

As this genetic variant is also carried on the X chromosome, men only have one copy (men have one X and one Y chromosome, while women have two X chromosomes).

See which version of rs2497911 you carry:

Another genetic variant on the X chromosome has a large effect on baldness. About 12% of people carry the ‘G’ variant at rs7061504, while the remaining 88% carry an ‘A’. For the approximately 12% of men carrying a G, the likelihood of baldness is increased by approximately 1.5 times.

See which version of rs7061504 you carry:

Anecdotally, many people have pointed out that baldness can appear to ‘skip generations’. As the X chromosome in men is inherited from their mothers, there may very well be some truth to this observation in people who carry genetic variants in rs2497911 and rs7061504.

Not all of the risk variants influencing baldness are on the X chromosome - there are many variants on the other chromosomes with large effects.

For example, approximately 1 in 4 people carry a ‘T’ at rs77410716 - these people have an increase in baldness of about 1.2 times compared to the people with a ‘C’ at this position.

The final example variant, a T at position rs182973285, is present in only roughly 1 in every 200 people, while 199 in 200 people carry a C. However, for those people who carry a T, the risk of baldness is increased by more than 2.5 times.

Unfortunately, this variant is not covered by many commercial DNA tests which use genotyping, so it will only be detected by whole genome sequencing, or imputation (a method for ‘filling in the blanks’ in genotyping arrays).

See which version of rs182973285 you carry: