Then the scientists sought common DNA variations responsible for changing the gene's activity and the amount of protein it made.

Like the voles and fruit flies, individuals may differ in gene activity because of DNA variations they inherited.

Jeffreys was studying DNA variation and the evolution of gene families in order to understand disease causing genes.

Last month seven new DNA variations associated with diabetes were discovered, and advances with other diseases are expected to be announced soon.

The new DNA variations are common but confer a lesser risk.

Results of studies based upon autosomal DNA variation have also been varied.

All together, different tissues in this single individual carried 14 different DNA variations, some of which were present in more than one tissue.

The San Diego company makes machines that test for DNA variations.

Though there are many sites of DNA variation along the 1.7 million-unit stretch, all had about the same strength of association with the disease.

And the existing genetic data testify that known DNA variations do not respect the boundaries of human groups.