It begins with receding hairlines, the forehead becomes higher, the hair at the back of the man's head gets thinner and thinner. Every second man suffers from greater or lesser hair loss. There are hardly any successful counter-measures despite an enormous range of obscure lotions and tinctures.
It has long been suspected that hereditary factors are important in causing hair loss. However, up to now it was unclear which genes are involved. The researchers in the team headed by Professor Markus Nthen of the Life & Brain Centre of the Bonn University Clinic and Dr. Roland Kruse of the Skin Clinic of Dsseldorf University Clinic seem to have now discovered one of the factors responsible for the first time.
For several years the researchers had searched nationwide for families in which several men were affected by hair loss. In blood samples taken from the volunteers they then looked for candidate genes and eventually discovered them: in their initial step they succeeded in narrowing down the search to a series of areas on various chromosomes. In an area where the largest contribution was suspected lay the gene for the androgen receptor. "One variant of this gene was found among men who suffered from premature balding at a very early stage very much more often than among men who still had a full head of hair when over 60," Professor Nthen says.
More androgen receptors in the scalp
Probably the genetic variant results in more androgen receptors in the scalp. "Our findings permit two explanations," Axel Hillmer from Prof. Nthen's team explains. "Either more androgen receptors are formed among the men affected, or the variant of the receptor which develops as a result of the genetic change is more stable and is not broken down so quickly. Both mechanisms can lead to the effect of the androgens beco
Contact: Prof. Markus Nthen
University of Bonn