Scientists at Bonn and Düsseldorf Universities have discovered an important hair-loss gene. During their study, the researchers investigated over 500,000 positions in the human genome, and found a gene variant which occurs clearly more frequently in bald men than in control persons.
The results are to be published in the November issue of the journal "Nature Genetics" (online publication on October 12th 2008).
In 2005, these scientists had already characterised the first hair-loss gene inherited through the maternal line, which explained why hair-loss in men often reflects that of their maternal grandfathers. This newly discovered gene, on the other hand, may now account for the similarity in cranial hair growth between father and son.
The researchers had concentrated their attention on the genomes of just under 300 men suffering from marked hair loss, investigating for this purpose over 500,000 variable sites in the genomes of their test subjects. Two positions frequently displayed a clear correspondence with baldness in these men – a clear indication that the genes located at those points were involved in hair-loss.
"In one of these conspicuous regions lies the gene for the androgen receptor," Dr Axel Hillmer of the Life & Brain Forschungszentrum (research centre) in Bonn states. "We had already learnt from an earlier study that this receptor was linked to hair loss. However, the other region was new to us."
This is only the second region of the genome that can definitely be associated with premature hair-loss.
"We are now trying to discover the role played by this genomic region in hair-growth," says Dr Felix Brockschmidt of Bonn University. "Only then will we know whether we on the right track for new forms of therapy for male hair-loss."
The study was conducted by the research teams headed by Professor Dr Markus Nöthen (Bonn University´s Institute of Human Genetics and Life & Brain-Center) and Privatdozent Dr Roland Kruse (Department of Dermatology, University Clinic Düsseldorf). Over a period of years, the scientists had collected blood samples from affected males all over Germany. As part of their study, they have been able to confirm their findings through additional sufferers in Australia. The Australian research team is headed by Nicholas Martin (Queensland Institute of Medical Research, Brisbane).
The results reveal that more than one gene is involved in the development of male hair-loss. These results also throw interesting light on the inheritance of baldness in that hitherto the only known risk gene for the androgen receptor lay on the X-chromosome, and was thus inherited from the mother – which accounts for the fact that in the case of hair-loss men often take after their maternal grandfathers. However, the newly discovered gene lies on chromosome 20, and can be inherited from both the mother and the father.
"This helps to provide an explanation for the similarity between father and son," declares Professor Nöthen.
(Source: Nature Genetics: Universität Bonn: October 2008)