Missing Eight Percent of DNA Revealed

Scientists at the Telomere to Telomere (T2T) consortium led by National Institutes of Health (NIH), UC Santa Cruz, and University of Washington, have published the first complete, gapless sequence of a human genome. It has been two decades since the Human Genome Project produced the first draft human genome sequence.

“Generating a truly complete human genome sequence represents an incredible scientific achievement, providing the first comprehensive view of our DNA blueprint,” says Eric Green. He is the director of the National Human Genome Research Institute, which is part of NIH. The statement comes from a press release issued by NIH.

“This foundational information will strengthen the many ongoing efforts to understand all the functional nuances of the human genome, which in turn will empower genetic studies of human disease.”

Six papers encompassing the completed sequence have been published in Science. And related papers have been published in other journals.

“Ever since we had the first draft human genome sequence, determining the exact sequence of complex genomic regions has been challenging,” said Evan Eichler, researcher at University of Washington School of Medicine.

“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.”

CNN notes that the Human Genome Project made history when it sequenced 92 percent of the human genome in 2003. But, after that, scientists have struggled to decipher the remaining eight percent.

This is what the T2T scientists have accomplished. The new research adds 400 million letters to the previously sequenced DNA. The full genome will allow scientists to analyze how DNA differs between people and whether these genetic variations play a role in disease.

“This complete human genome sequence has already provided new insight into genome biology, and I look forward to the next decade of discoveries about these newly revealed regions,” says Karen Miga, research leader at UC Santa Cruz.

Geneticist Colin Johnson called the work “truly ground-breaking,” as reported by BBC News. He compared the previously missing eight percent of the human genome to “the dark matter of the genome that we knew was there but couldn't get to.” And he added that now we have “the full description of the book of life, with all of the paragraphs and pages assembled."

Sequencing a person's entire genome should get less expensive and more straightforward in the coming years.

“In the future, when someone has their genome sequenced, we will be able to identify all of the variants in their DNA and use that information to better guide their healthcare,” says Adam Phillippy, research leader at NHGRI.

"Truly finishing the human genome sequence was like putting on a new pair of glasses. Now that we can clearly see everything, we are one step closer to understanding what it all means."