The role of genetics in male-pattern baldness

In the largest genetic study of male patterned baldness to date, scientists at the University of Bonn working in collaboration with 23andMe and other baldnessinstitutions, have found more than 60 genetic variants associated with balding.

The findings offer not just new insights into the biology of the condition, but potentially greater understanding of other health conditions that are associated with it.Despite being widely studied and very common  — particularly among men of European ancestry — male pattern baldness is poorly understood. Scientists know losing one’s hair is highly heritable and dependent on testosterone, but little else is known about the complex underlying biology.Because losing one’s hair early in life is also associated with serious health conditions — prostate cancer and Parkinson’s disease, for instance — understanding how and why men go bald, could help our understanding of a wide range of conditions.

“These novel insights into the genetic basis of (male pattern baldness) and its association with other traits may help to elucidate the evolutionary forces responsible for the relatively high prevalence of (it) in the European population,” the study authors said.

For this paper, the team of researchers lead by Stefanie Heilmann-Heimbach of the University of Bonn, looked at data from more than 22,000 people, including about 17,000 23andMe customers who consented to participate in research. The remainder of the data used for this study came from several smaller cohorts in Europe and Australia.Using these data for their large-scale meta-analysis, the researchers found 63 genetic variants associated with male pattern baldness, 22 of which are novel.

The variants were found in or near genes that play a role in hormonal status, melatonin signaling, fat cell differentiation, and the growth phases of hair. Six of the genetic variants identified are on the X-chromosome and may account for some of the resemblance of hair loss between men and their grandfathers on their maternal side, according to the researchers. The remaining variants found in this study are on the autosomes, the non-sex chromosomes.

Taken together these findings highlight genes that are likely involved in the biological process that leads to balding and as such the researchers believe that they could be promising targets for drugs to treat the condition.Beyond that, the research also illustrates that male pattern balding shares similar biology with other traits and conditions.

“This may have strong implications for the evaluation of male pattern baldness as an early prognostic marker for different phenotypes,” the researchers said.

The authors also believe the findings could lead to the “repurposing” of existing drugs for male pattern baldness. They point out that two drugs that were originally developed to treat hypertension and prostate hyperplasia — minoxidil and finasteride — resulted in stopping hair loss and regrowing hair as a side effect to the treatments.

The study appears in the journal Nature Communications.