03 October 2011
ByAppeared in BioNews 627
A study analysing three different, but closely related, African populations has identified that a cancer gene is present at a surprisingly high frequency; akin to those usually associated with evolutionary advantages.
This research, published in American Journal of Human Genetics, suggests that the prostate stem cell antigen (PSCA) gene could have a beneficial role, as well as being linked to cancer.
Dr Alkes Price, a senior author on the study said: 'We presume this mutation also confers some benefit to those who carry it'. He said that finding signals for natural selection will allow scientists to uncover the genetics of disease resistance, and hopes it will help to identify new treatments and improve existing ones.
This study represents the first analysis of differences in the genome-wide data available for over 12,000 individuals of African-American, Nigerian or Gambian descent. In general, the scientists observed that the genomes from across all the three African populations were broadly similar and confirmed previously identified highly selected for genetic regions amongst this population.
'Looking at closely related populations is significant because there are not many genetic differences between them. So when there is a difference, you know that something interesting is going on', explained Gaurav Bhatia, a graduate student from the Massachusetts Institute of Technology, who carried out the study.
Indeed, they discovered four regions of the genome that, according to Bhatia, 'really stood out'. Three of the genes in these regions have already been demonstrated to have a link to malaria resistance. The other identified genetic region has the gene PSCA present which is known to be linked to bladder and prostate cancer. However, according to New Scientist, the researchers don't know what benefit it confers and further research is required to determine the cause of the selection pressure.