Scientists have updated the human genome to make it more equal and comprehensive.. How?

Scientists have updated the human genome to make it more equal and comprehensive.. How?
Scientists have updated the human genome to make it more equal and comprehensive.. How?

Dubai, United Arab Emirates (CNN) — Scientists have compiled a new draft of the human genome that better captures humanity’s genetic diversity.

The new pangenome included the DNA of 47 individuals from every continent, except Antarctica and Oceania. Participating scientists said this would improve our ability to diagnose disease, discover new drugs, and understand genetic variants that lead to poor health or a particular physical trait.

Until now, geneticists have used a single human genome, largely based on a single individual, as a standard reference map for discovering genetic changes that cause disease. This may have missed some of the genetic diversity between individuals and different populations around the world.

“This reference pangenome represents a remarkable scientific achievement, providing an expanded view of the DNA blueprint of humanity, with much greater human diversity than previous reference sequences,” Eric Green, director of the US National Human Genome Research Institute, which funded the project, said at a news conference.

“Having a high-quality human pangenome repertoire that increasingly reflects human diversity, enables scientists and healthcare professionals to better understand how genetic variants affect health and disease, and move us toward a future in which genomic medicine benefits everyone,” Green said.

The Pangenome, a digital fusion of sequences that can be used to compare, construct and study other human genome sequences, is still in draft form. The researchers hope to have 350 people on board by the middle of 2024. The scientific achievement is detailed in several papers published in Nature and its partner journals on Wednesday.

Benjamin Schwessinger, assistant professor at the Australian National University, who was not involved in the project, explained that you can imagine this achievement as a new roadmap for getting your kids to school. Instead of taking the same route every day, your neighbor might take a slightly different route on a side street.”

“This new, pan-genome approach “maps out these alternative pathways that make us humans so distinct from one another,” Schwessinger said in a statement.

Genetic variation

While each person’s genome varies slightly, by about 0.4% compared to the next person on average, the human genome is huge, consisting of 3.2 billion pairs. This means that there are still many important genetic differences between individuals and populations around the world.

The four building blocks of DNA – adenine (A), cytosine (C), guanine (G) and thymine (T) – form specific pairs and the association of these base pairs forms the structure of DNA.

Genomic variation may be small, consisting of differences in one or a few DNA bases, or it can be large structural variants of 50 base pairs or greater. These larger structural variables can have important health implications, such as the functioning of the immune system.

The new reference includes more diverse genetic sequences and adds 119 million base pairs to a library of 3.2 billion base pairs previously known to make up the human genome, deepening and making our understanding of human genetic diversity more complete.

“The pangenome reveals the structure of diversity and how it affects genes and will have a huge impact on genome research,” said Benedict Patten, associate professor of biomolecular engineering at the University of California, Santa Cruz, and associate director of the University of California, Santa Cruz Genomics Institute.

“It also reveals new biology,” he said. “We get a better picture of how some of the more complex regions of the genome differ. Until now, the composition of these rapidly evolving regions has been largely invisible to us.”

The first draft of the human genome was released in 2001, and it was only fully completed in 2022. “It’s been a great tool,” said Karen Mega, associate professor in the Department of Biomolecular Engineering at the University of California, Santa Cruz, and associate director of the Genomics Institute at UC Santa Cruz. invaluable to researchers, and ushered in a new era of scientific discovery, technological innovation, and genomic medicine.”

“Understanding and cataloging these differences between genomes will allow us to understand how cells function and their biology, as well as understanding genetic differences and how they contribute to understanding human diseases,” Megha added.

Credit: From Darryl Leja/NHGRI

Eliminate bias

The original human reference genome was mostly based on anonymous volunteers who responded to an advertisement in the Buffalo Evening News on March 23, 1997, with a donor accounting for 70% of the sequence, according to NHGRI.

The 47 anonymous individuals included in the first draft of the pangenome project were among those who participated in the 1000 Genomes Project, a catalog of shared human genetic diversity completed in 2015. The team is in the process of recruiting new individuals to represent some of the populations not included in the 1000 Genomes Project, particularly people Of Middle Eastern and African descent.

Other projects aimed at expanding genomic databases “often miss the mark in showing respect” to communities in low-income countries and indigenous peoples, who say their samples and data are used to further the goals of scientists and institutions in rich countries, notes the paper published in Nature this year. Past about the pangenome project.

The team made sure to avoid such mistakes. Barbara Koenig, professor emeritus of medical anthropology and bioethics at the University of California, San Francisco, said ethical considerations and “the principle of fairness” were a key part of our endeavor.