More Harmful Genetic Changes in DNA of European Americans than African Americans

African DNA has more genetic diversity
By Roger Highfield, Science Editor
Last Updated: 1:01pm GMT 21/02/2008







Human migration from Africa to Europe more than 30,000 years ago appears to have left its mark on the genes of Europeans today.


Schematic of worldwide human genetic variation, with colours representing different genetic types
The DNA of European-Americans appears to carry proportionately more harmful genetic changes than that of African-Americans, because they emerged from a smaller and less diverse population.

The study of 35 people, published in Nature by a team led by Prof Carlos Bustamante of Cornell University, New York State, shows that the proportion of single letter spelling variations in the human genetic code that are probably harmful and unique to that particular population are significantly higher in the European-Americans (16 per cent) than in the African-American sample (12 percent) his team analysed.

"What is happening at an individual level will vary tremendously within and among populations," stressses Prof Bustamante, explaining that the effect can only be seen in the population level and it is not known how these deleterious mutations affects disease risk.