The International HAPMAP project tries to map the diversity of the genetic equipment of man. Now a new, greatly extended record is ready
The assertion that all relatives of a particular population group shared their fundamental genetic equipment, is first trivial, because often in the phanotype can be seen, so even for the scientifically unchecked eye. For years, researchers have been concerned with the question of what is still behind the obvious. Why should one go to the search for the Jewish, the Yoruba or the Han Chinese gene?
First, individual differences in the bench equipped a lot about the history of humanity. Who came from where, who is using whom? In the genes, every person also carries traces of his past. In June, two studies looked at this aspect of the example of the Jews — a paper appeared in American Journal of Human Genetics, the other in the science magazine Nature. Both show a relatively rare phanomen in history: the fact that the composition of the gene pool of a people is preserved by his culture, his religion.
Since the year 800, Jews have only married themselves and the influx of converted discontinued, hoard the inflow of genes from outside. Jews, no matter what origin, are therefore mostly closely related to each other than other people who live in their area of origin. Anyway, except for Athiopian and Indian Jews who have a lot common with other athiopians or otherwise. The origin of the religious community can be pursued in this way quite clearly in the Middle East.
That may be interesting for the feuilleton — from scientific point of view more interesting are these studies (including the two mentioned), however, what their potential medical application is concerned. By visible the differences between the ethnic groups, one can find out which mutations associated with certain diseases. This approach pursues the International HAPMAP project on the worldwide.
In Nature unavailable the researchers involved this week the results of Phase III of the project. For this they analyzed the gene sequences of 1184 people from eleven different populations, including Han Chinese, Indian, Japanese, Massai, Italian and Yoruba. However, a complete gene analysis in this extent is still too expensive, therefore one ared on 856 genes of gene, which insisted on average 7200 base pairs — a total of around 0.1 percent of the human genome. From this one can now put together so-called haplotypes — variants of a base sequence in one and the same gene portion.
The database extended with HAPMAP 3 allows for researchers to demand more rare occurring variants. The hope of science: if it succeeds in connecting inheritable diseases with these markers, one could also learn more about the nature of these diseases. But that should now deal with others — the HAPMAP project merely provides the data in a free accessible database. In so-called association studies, one can now compare groups with a certain disease and certain haplotype with control groups that are not affected by the disease — the exclusive for the hereditary disease must then be found as part of the corresponding haplotype.