THURSDAY, Feb. 21 (HealthDay News) -- Genomic analysis has shown that African populations have the most genetic variation, with diversity decreasing with increasing distance from Africa, and are less likely to carry damaging alleles, according to two studies published in the Feb. 21 issue of Nature.
In the first study, Kirk E. Lohmueller, from Cornell University in Ithaca, N.Y., and colleagues estimated the number of damaging single-nucleotide polymorphisms (SNPs) in 15 African-Americans and 20 European-Americans. They found that African-Americans had higher levels of SNP heterozygosity (carrying one mutant allele), while European-Americans had higher levels of SNP homozygosity (carrying two mutant alleles). European-Americans were significantly more likely to carry SNPs that resulted in amino acid changes and SNPs that were inferred to be "probably damaging," the report indicates.
In the second study, Mattias Jakobsson, Ph.D., from the University of Michigan in Ann Arbor, and colleagues analyzed genotypes at 525,910 SNPs and 396 copy-number-variable loci in 29 populations around the world. They found that linkage disequilibrium increased with increasing distance from Africa. An analysis of the global distribution of copy-number variants largely agreed with population structure analyses for SNP datasets of similar size.
"Our results produce new inferences about inter-population variation, support the utility of copy-number variants in human population-genetic research, and serve as a genomic resource for human-genetic studies in diverse worldwide populations," Jakobsson and colleagues conclude.
Abstract - Lohmueller
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Abstract - Jakobsson
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