In a recent study of people of African descent, scientists have uncovered new segments of DNA that may represent new genes, segments that had been ignored previously. In 1997, the Human Genome Project completed the first human genome sample, with 70% of the first DNA sample coming from a single person, referred to as RP11. Since then, this first human genome has been undergoing a perpetual refinement process, with additional sequences from other individuals added. It has been used as a reference genome, a standard that nearly all other human DNA that has been sequenced is compared to, even though the vast majority of this reference genome is still from RP11. Since genetic codes are unique, using the RP11 reference genome as a standard for all humans has resulted in biases within genetics research.

The new study has informed scientists  just how limited the RP11 reference genome is. From over the 910 people’s DNA that was studied, 300 million letters of DNA emerged in 125,715 separate DNA segments that are not in the RP11 reference genome. As people of African descent are genetically diverse, their DNA is least likely to match up to the reference genome, even though scientists have postulated that RP11 was possibly African American as well. However, using a single reference genome to represent the total human population has proved to be limited and incomplete.

Currently, DNA sequencers separate a genome into short segments that are “read” and then put together with algorithms using the reference genome to determine where each segment belongs. If a new segment arises that differs from the reference genome, the algorithms and scientists usually ignore it. But scientists are now working to better understand large structural variations to improve upon the Human Genome Project and other genetic studies.

Source: The Atlantic