The Claim: Male Pattern Baldness Is Inherited Through the Mother

October 2005

THE FACTS Men who notice their hair vanishing prematurely have long been inclined to lay the blame squarely on their mothers, prompted by the old wives' tale that male pattern baldness is a trait passed down on the maternal side.

Really? Much of the evidence for the claim was anecdotal, but now new research suggests that the finger-pointing may be warranted.

Scientists have isolated a gene variation that turned up frequently in balding men during a study of 95 families having at least two brothers with early hair loss, researchers reported in July in The American Journal of Human Genetics.

The culprit, a variant of the androgen receptor gene, is on the X chromosome, which men get from their mothers (Y comes from fathers).

The scientists, from the University of Bonn, found that this variant increases the effects of testosterone and other male hormones, called androgens. High levels of androgens are known to cause baldness.

The researchers determined that the gene variant they isolated was the "cardinal prerequisite" for premature balding in the men they studied, about 200 in all. But they also stressed that a number of genes and factors may also be involved to a lesser extent, including premature hair loss on a father's side.

THE BOTTOM LINE Male pattern baldness appears to be largely influenced by genes inherited from mothers.