The Human Genome Project — which built the blueprint, called the human reference genome — has changed the way medical research is conducted, says Ting Wang, a geneticist at Washington University School of Medicine in St. Louis. “It’s highly, highly valuable.”
“That said, the human reference genome we use has certain limitations,” Wang says.
For one thing, it isn’t really finished; gaps remain in the more than 3 billion DNA letter long template, especially in stretches of repetitive DNA.
And despite being a compilation of more than 60 people’s DNA, the reference doesn’t fully encapsulate the full range of human genetic diversity.
One of the easiest ways to compile a complete catalog of human diversity is to decipher, or sequence, the genomes of 3 million Africans, medical geneticist Ambroise Wonkam of the University of Cape Town in South Africa, proposes in a commentary also published February 10 in Nature. Africa is where modern humans originated, and study after study has uncovered thousands to millions of new genetic variants among people of African descent
“We need a database reference that is representative of humankind,” that is rooted in African origins, Wonkam says. “African population genomic variation is the next frontier” in human genetics.