Male pattern baldness affects 30 percent of men under 30 and 80 percent of men by the time they’re 80 years old. Medically known as androgenetic alopecia, baldness is often blamed on hormones and genetic predisposition. However, a recent study — the largest genetic analysis of male pattern baldness ever conducted — has become the first to detail exactly which genes are involved. It’s looking likely that an algorithm will be able to tell future men whether they should start asking their barber for “The Rock.”
In a paper published in PLOS Genetics, a team of researchers from the University of Edinburgh explain that they have pinpointed 287 genetic regions associated with this form of baldness. Many of these genes, they explain, are associated with hair structure and development — which is likely why they are associated with hair loss — while other genes associated with more hair loss were linked to shorter stature, fewer offspring, and a lower risk of bipolar disorder.
The top gene-based hit was the gene on the X chromosome encoding the androgen receptor, a DNA-binding receptor that regulates gene expression). It was one of many genes pinpointed on the X; in a statement, co-author Saskia Hagenaars, a Ph.D. student, said, “It was interesting to find that many of the genetics signals for male pattern baldness came from the X chromosome, which men inherit from their mothers.” This adds further and substantial evidence that baldness is, at least in part, influenced by the genetics of a man’s mother.
The scientists pulled this information from a sample of 52,000 white, British men between the ages of 40 to 69 years old. The genetic analysis underlying this study examined genetic profiles already created by the United Kingdom Biobank and paired with the questionnaire about hair loss below, which they answered themselves. Within this group, 16,174 reported no hair loss, 12,134 had slight hair loss, 14,234 reported moderate hair loss, while 9,781 men had severe hair loss.
With the data on the genetic variants that led to different forms of hair loss, the scientists created a prediction algorithm to determine to what degree men would go bald. As of now, the scientists can’t confidently predict results for individuals, but they can “identify subgroups of the population for which the risk of hair loss is much higher”, lending to the belief that the algorithm will continue to improve.
“We are still a long way from making an accurate prediction for an individual’s hair loss pattern,” said the study’s principal investigator, Riccardo Marioni, Ph.D., in a statement. “However, these results take us one step closer. The findings pave the way for an improved understanding of the genetic causes of hair loss.”
Marioni and his team also think this genetic data set could be a massive help in understanding which genes to target for intervention. While scientists have begun trials for drugs treating other forms of baldness, like alopecia areata, there is no long-term treatment for male pattern baldness yet — despite what informercials may have you believe.