Baldness: New Risk Factors Identified

NOUVELOBS.COM | 13.10.2008 | 13:08

Researchers have discovered new genetic factors that increase the risk of baldness in men. Maternal transmission, therefore, is no longer the only factor implicated in hair loss.

Two independent teams of researchers have discovered new genetic variants on chromosome 20, inherited from the father or the mother, which increase the risk of baldness. A team led by Axel Hillmer (University of Düsseldorf, Germany) and Felix Brockschmidt (University of Bonn) had already identified an X chromosome gene linked with hair loss, which would explain why baldness in men often resembles that of their paternal grandfather.

This time, the German researchers focused on the genetic profile of 300 men with alopecia. They compared 500,000 positions in the genome and identified two variants that were implicated in hair loss. One of these variants is linked to the androgen (male hormone) receptors, just like the already-implicated X chromosome gene.

Another team headed by Vincent Mooser (GlaxoSmithKline), Brent Richards (McGill University, Canada), and Tim Spector (King's College London, UK), reached the same conclusions by studying the DNA of over 2,500 men. These researchers calculated that when the two risk factors, that of the X chromosome and that of chromosome 20, are both present, the risk of becoming bald is increased sevenfold.

These studies have been published in the Nature Genetics journal (e-journal, 12 October).

Given that 40% of adults, men and women, are affected by hair loss, treatments represent a huge market.

"The earlier alopecia is treated, the more effective the remedies are," explains Tim Spector. The researchers stress, however, that these latest findings will not bring about new treatments in the medium term.

Cécile Dumas

Sciences et Avenir.com

13/10/08