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The first human "pangenome" is intended to catalog genetic diversity

Scientists have published draft results from a comprehensive research effort underway to capture all human genetic variation

The human genome represents a collection of genetic sequences from a diverse group of people. Illustration: depositphotos.com
The human genome represents a collection of genetic sequences from a diverse group of people. Illustration: depositphotos.com

More than twenty years after the first draft genome from the groundbreaking Human Genome Project was published, researchers have released a draft of the human "pangenome" - a picture of what will be a new reference genome in genetic research that captures more of human diversity than was previously available. Geneticists welcomed the milestone, but also noted important ethical considerations associated with the effort to make genome research more inclusive.

"It's like going from a black and white TV to 1080p," says Kyolu Fox, a genome scientist at the University of California, San Diego.

"It's something we've all been waiting for," says Ayme Lomke, a geneticist who holds a joint position at the University of Liege in Belgium and the University of Kinshasa in the Democratic Republic of Congo. "In the current reference genome, not only is part of the genomic information missing, but also, and this is most important, it lacks diversity," he says.

The draft genome, published in Nature on May 10, was created by the Human Pangenome Consortium for Attribution. The goal of the international project that began in 2019 is to map all human genetic variation, to create a comprehensive reference genome against which geneticists can compare other sequences. Such a reference genome would help studies investigating potential links between genes and diseases.

The Pangenome draft follows the publication in 2022 of the first complete sequence of the human genome, which filled in gaps left by the original Human Genome Project. But unlike the original draft human genome and the 2022 genome, both of which were produced primarily from the DNA of just one person, the draft Pangenome represents a collection of sequences from a diverse selection of 47 people from around the world, including people from Africa, the Americas, Asia and Europe.

Aymir Kenny, a geneticist at the Icahn School of Medicine at Mount Sinai in New York City, and her colleagues computationally arranged all these sequences and created a "panganome graph" - conceptually similar to a map of the London Underground, where branching paths indicate genetic variation. The researchers found that Pangenome allowed them to identify twice as many structural variants – large genomic changes such as duplications or deletions of genes – per person than was possible using the original, linear reference genome. The team intends to analyze sequences from 350 people by mid-2024.

Many of the samples being analyzed are from people who participated in the 1000 Genomes Project, a sequencing effort that began in 2008 to map genetic variation in 26 diverse populations. The participants' frozen DNA samples are thawed and reanalyzed by the Panganome Project using a more detailed technique called "long read sequencing." It analyzes longer pieces of DNA each time compared to older sequencing methods, and can differentiate between pairs of chromosomes from the same person. "It's an approach with a much higher resolution," says Fox.

For the article in NATURE

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