Scientists Publish Comprehensive ‘Gapless’ Human Genome

A collaboration between researchers from government, academic, and private organizations, called the Telomere-to-Telomere Consortium, recently produced the first fully “gapless” human genome.  

In a paper published last week in Science, researchers emphasized that this discovery adds 200 megabases of genetic information to the original human genome and allows for a detailed characterization of the centromeric satellite repeats, transposable elements, and segmental duplications. 

The “gapless” genome also allows experts to explore new territories in medicine and gain practical applications in precision medicine, which could provide insights into the mechanisms of aging. 

“If there’s any blueprint on this planet we should want to know from one end to another, it’s humans,” Eric D. Green, director of the National Human Genome Research Institute, told the Washington Post.  

Researchers discovered the gapless human genome on a cell line developed decades ago that originated with a rare tumor type, “complete hydatidiform mole.” Notably, this tumor type formed on the union of a single sperm and an ovum that lacked the woman’s DNA.  

In 1990, an international team of researchers launched The Human Genome Project (HGP) to sequence and map all of the genes (the genome) of humans. The project was completed in 2003 and gave experts the ability to read nature’s complete genetic blueprint for building a human being for the first time.  

But the genome still had gaps and sections with redundancies that made their mapping impossible. Some of the gaps were on telomeres, while others were on centromeres.  

Therefore, the newly discovered genome will become a reference guide to genetic variations seen in human beings, especially as more genomes from diverse populations worldwide become fully sequenced and build out the library of blueprints, researchers said.  

“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,” said Karen Miga, a geneticist at the University of California at Santa Cruz and co-founder of the T2T consortium. “If we didn’t have these regions, we wouldn’t have life as we know it.” 

And the new unique cell line represents no person that has ever lived, stated Adam Phillippy, a co-founder of the consortium and head of the Genome Informatics Section of the National Human Genome Research Institute.