A new study published in Nature Genetics on Sunday 16 September 2007 show that common, complex diseases are more likely to be due to genetic variation in regions that control activity of genes, rather than in the regions that specify the protein code.
This surprising result comes from a study at the Wellcome Trust Sanger Institute of the activity of almost 14,000 genes in 270 DNA samples collected for the HapMap Project. The authors looked at 2.2 million DNA sequence variants (SNPs) to determine which affected gene activity.
They found that activity of more than 1300 genes was affected by DNA sequence changes in regions predicted to be involved in regulating gene activity, which often lie close to, but outside, the protein-coding regions.
"We predict that variants in regulatory regions make a greater contribution to complex disease than do variants that affect protein sequence," explained Dr Manolis Dermitzakis, senior author from the Wellcome Trust Sanger Institute. "This is the first study on this scale and these results are confirming our intuition about the nature of natural variation in complex traits.
"One of the challenges of large-scale studies that link a DNA variant to a disease is to determine how the variant causes the disease: our analysis will help to develop that understanding, a vital step on the path from genetics to improvements in healthcare."
Past studies of rare, monogenic disease, such as cystic fibrosis and sickle-cell anaemia, have focused on changes to the protein-coding regions of genes because they have been visible to the tools of human genetics. With the HapMap and large-scale research methods, researchers can inspect the role of regions that regulate activity of many thousands of genes.
The HapMap Project established cell cultures from participants from four populations as well as, for some samples, information from families, which can help to understand inheritance of genetic v
|Contact: Don Powell|
Wellcome Trust Sanger Institute