World map with geographic coordinates of populations sampled in the study.PETER H. SUDMANTGenetic differences among ethnically diverse individuals are largely due to structural elements called copy number variants (CNVs), according to a study published today (August 6) in Science. Compared with other genomic features, such as single nucleotide variants (SNVs), CNVs have not previously been studied in as much detail because they are more difficult to sequence. Covering 125 distinct human populations around the world, geneticist Evan Eichler at the University of Washington in Seattle and an international team of colleagues studied the genomes of 236 people—analyzing both SNVs and CNVs.
“The take-home message is that we continue to find a lot more genetic variation between humans than we appreciated previously,” Eichler told The Scientist.
“This is a really exciting study of CNVs in worldwide human populations and has a much finer resolution than what had been done before,” said Kirk Lohmueller, who studies human genetic variation at the University of California, Los Angeles, and was not involved in the work.
Classified as deletions or duplications, CNVs are genomic loci that can greatly vary in the number of copies, and are often located in regions of highly repetitive content, making them more difficult to sequence compared to SNVs. Thus far, the vast majority of human genome analyses—including from the Human Genome Project and the 1,000 Genomes ...
