Researchers assemble first complete human genome sequence

A team of researchers assembled the first complete sequence of a human genome, 2 decades after the Human Genome Project formed the first incomplete draft sequence, according to the NIH.

The first draft mapped about 92% of the DNA included in a human genome sequence, the National Human Genome Research Institute (NGHRI) said in a press release. Innovations in technology have allowed researchers in the Telomere-to-Telomere (T2T) consortium to uncover the remaining 8%.

Six papers detailing the completed sequence have been published in Science.

“Ever since we had the first draft human genome sequence, determining the exact sequence of complex genomic regions has been challenging,” Evan Eichler, PhD, a researcher at the University of Washington School of Medicine and co-chair of the T2T consortium, said in the release. “I am thrilled that we got the job done. The complete blueprint is going to revolutionize the way we think about human genomic variation, disease and evolution.”

The remaining 8% of the genome discovered by Eichler and colleagues includes numerous genes and repetitive DNA amounting to the approximate size of an entire chromosome. The once-missing genes are important since they “can contain immune response genes that help us adapt to and survive infections, plagues and viruses,” Eichler said during a press conference held by NGHRI.

The genes can also be used to detoxify agents and predict drug responses, he added.

The now complete genome represents a 3.055 billion-base pair sequence with gapless assemblies for all chromosomes except Y. It corrects errors present in the first reference genome and introduces nearly 200 million base pairs of sequence containing 1,956 gene predictions, 99 of which are thought to be protein coding, the researchers wrote in one of the Science papers.

“The availability of a complete genome sequence will advance our understanding of the most difficult-to-sequence and repeat-rich parts of the human genome,” Adam Phillippy, PhD, a researcher at NHGRI, told Healio. “In the future, when someone has their genome sequenced, researchers and clinicians will be able to identify all of the variants in their DNA and use that information to better guide their health care. Knowing the complete sequence of the human genome will provide a comprehensive framework for scientists to study human genomic variation, disease and evolution.”

References:

Nurk S, et al. Science. 2022;doi:10.1126/science.abj6987.

Researchers generate the first complete, gapless sequence of a human genome. https://www.genome.gov/news/news-release/researchers-generate-the-first-complete-gapless-sequence-of-a-human-genome. Published March 31, 2022. Accessed March 31, 2022.