"These are part of our recent evolution and a step along the way to understanding the origin and personal consequences of genetic change, not least for our wellbeing. This is a first generation map of biologically important DNA sequence variation"
The understanding of the genetic basis of gene activity will help medical research to provide individuals with information about their personal predisposition to disease.
The study was a massive undertaking: it included HapMap genotype data on 700,000 SNPs located close to genes, as well as 25,000 sites interrogated for potential structural variation to examine copy-number differences, looking at the activity of 14,000 genes in 210 unrelated individuals.
SNP and CNV variation correlated with altered activity in almost 900 and 240 genes, respectively. The HapMap has been invaluable in detecting variants involved in many diseases and these results suggest that the CNV index will prove similarly useful.
"The remarkable finding was that there is such little overlap in the genes found by using the two indices," commented Dr Matthew Hurles, also a leader of the project at the Wellcome Trust Sanger Institute. "Only about 10% of the activity variants associated with a CNV were also associated with a SNP.
"This suggests that we must include CNV studies in our searches for genetic variation associated with disease or we will be missing a lot of the important genetic effects."
The results show that at least 10-20% of heritable variation in gene activity is due to CNVs. The team found associations that included previously known examples, such as UGT2B17, which has been associated with prostate cancer, proving that the new
Contact: Don Powell
Wellcome Trust Sanger Institute