EthnicMajority

(The Root) Before the advent of DNA testing, scholars relied on shipping records that listed the African ports from which slaves were exported to determine where in Africa the African-descended population of the United States originated. But these lists were quite limited because they noted only the port of departure and not the actual community from which the enslaved were taken. 

Advancements in DNA analyses, along with African shipping records, have revealed that African Americans do not have roots in the entire continent. A relatively small number of African groups supplied the lion's share of the ancestral African population.

In fact, three large regions of Atlantic Africa were the major contributors to the slave trade: Upper Guinea, including the modern countries of Senegal, Mali, Gambia, Guinea, Sierra Leone and Liberia; Lower Guinea, including the southern portions of Eastern Ivory Coast, Ghana, Togo, Benin and Nigeria; and West Central Africa, which encompassed mostly the western portions of the Democratic Republic of Congo and Angola. In all, these regions made up only about 15 percent of Africa's total area, all on the Atlantic side of the continent.

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(Physorg.com) UCLA life scientists and colleagues have produced one of the first high-resolution genetic maps for African American populations. A genetic map reveals the precise locations across the genome where DNA from a person's father and mother have been stitched together through a biological process called "recombination." This process results in new genetic combinations that are then passed on to the person's children.

The new map will help disease geneticists working to map genetic diseases in African Americans because it provides a more accurate understanding of recombination rates among that population, said the senior author of the research, John Novembre, a UCLA assistant professor of ecology and evolutionary biology and of bioinformatics. The map could help scientists learn the roots of these diseases and discover genes that play a key role in them.

The study was published July 20 in the online version of the journal Nature Genetics and will be published in the print edition at a later date.

"Research aimed at finding disease variants will be improved by this tool, which could lead to better medications to help ameliorate the effects of those disease variants," Novembre said. "Health researchers can use a recombination map to refine where a disease gene might be."

Prior to this research, which was conducted by scientists from seven institutions, recombination had mainly been studied in European populations.

"Now we have a map for African Americans that researchers can use as a tool, instead of using a European map or an African map," said Novembre, a member of UCLA's Interdepartmental Program in Bioinformatics.

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(Cancer Network) Lung cancer is not a discriminate disease, but the disease burden is especially high on African Americans in the U.S. The statistics are stark: African-American men are 37% more likely to develop lung cancer than white men and are 22% more likely to die of it. In addition, only 12% of African Americans live longer than five years after a diagnosis of lung cancer, compared with 16% of whites, according to a recent report by the American Lung Association (see Fact box).

One suggested reason for this gap in outcomes is differences in race-based genetics. In the era of personalized medicine and treatments that target specific disease pathways, identifying genetic differences among populations is becoming increasingly important to optimize benefit.

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