A group of researchers announced on Mar. 31 that they’ve finally sequenced a complete human genome—essentially finishing a how-to manual on human life—work that was believed to have been concluded in 2003.
According to the journal Science, two decades ago, scientists with the Human Genome Project believed their work was concluded, but what they discovered was that 8% of the genome sequencing was, in fact, “unfinished.”
"Some of the genes that make us uniquely human were actually in this 'dark matter of the genome' and they were totally missed," Evan Eichler, a University of Washington researcher said, according to CBS News. "It took 20-plus years, but we finally got it done."
As The Washington Post explains, the remaining 8% was a mystery unsolved mostly because the technology at the time simply wasn't up to the task. “Ever since we had the first draft human genome sequence, determining the exact sequence of complex genomic regions has been challenging,” Eichler, co-chair of the Telomere-to-Telomere (T2T) consortium of scientists who conducted the most recent research, said in a news release. “The complete blueprint is going to revolutionize the way we think about human genomic variation, disease, and evolution.”
Eichler told the Associated Press that scientists used to believe that human DNA contained a certain amount of “junk,” but he says he never shared that belief. “Some of us always believed there was gold in those hills,” he told AP.
Mapping the full human genome was never a small job. To put the project’s scope into perspective, AP explains the vastness of the undertaking like this:
“The human genome is made up of about 3.1 billion DNA subunits, pairs of chemical bases known by the letters A, C, G, and T. Genes are strings of these lettered pairs that contain instructions for making proteins, the building blocks of life. Humans have about 30,000 genes, organized in 23 groups called chromosomes that are found in the nucleus of every cell.”
Karen Miga, a University of California at Santa Cruz geneticist, told the Post that this latest discovery will help to explain how genes work for all species—not just humans. “There are these incredibly large and persisting gaps that have been in our genome for decades and they represent really important parts of our genome. If we didn’t have these regions, we wouldn’t have life as we know it,” Miga said.
This completed chart will ultimately give researchers a better insight into how humans age, how to better understand and treat illnesses such as heart disease and cancer, and revolutionize “fields of science, including microbiology, virology, infectious disease, and plant biology,” according to the journal Biomedical Central.
"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 health care,” T2T consortium co-chair Adam Phillippy said in a statement from National Health Human Genome Research Institute. “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.”