Scientists on Wednesday published the first human ‘pangenome’, cataloging the complete range of genes in the human race to date, with the hope that it could help explain a wide range of diseases.
David Adelson, a geneticist at the University of Adelaide in Australia, hailed the announcement as “the harbinger of a new era in genetic diagnostics.”
The first human genome, which combines all the genetic material unique to a human, was sequenced in 2003. It has been released as a reference point for other human genomes.
Above all, it has made it possible to identify the genes responsible for specific diseases, launch research towards more personalized medicine, and shed light on the mechanism of human evolution.
But 70% of the sequences of this first genome came from one individual – who answered an ad in a newspaper in the US city of Buffalo in 1997 – from twenty other individuals. This has limited its use to other ethnic groups.
The first Pangenome Series of Scientific Articles was presented in the journal Nature by a group of scientists assembled in the Human Pangenome Reference Consortium (HPRC).
It compiles the genomes of 47 individuals of various origins, and aims to collect the genomes of 350 individuals by mid-2024.
Of these 47, who remain anonymous, more than half are from Africa, a third from the Americas, six individuals from Asia and only one Ashkenazi Jew from Europe. Oceania is not mentioned.
Genome is the genetic map of any organism. It contains all the DNA elements that contain the instructions to live and grow.
Two people’s genome is more than 99% the same, but the remaining differences can make certain diseases easier for one person to develop than for another.
The reference genome may help explain these differences in genetic patterns, explained Benedict Baden, a University of California researcher and co-author of the study.
“This will improve genetic testing and at the same time provide a better understanding of the contribution of all types of genetic variation to health and disease,” he told a news conference.
Another co-author of the study, Erich Jarvis of Rockefeller University in the US, gave the example of groups of genes known as the major histocompatibility complex (MHC), which are involved in the functioning of the immune system.
“Studying the heterogeneity of MHCs has so far been impossible” because it is best between individuals, the researcher pointed out.
Advances in this area would benefit organ transplants to avoid rejection.
According to Australian geneticist David Adelson, the first version of this pangenome has already increased the accuracy of detecting genetic mutations by about 34%.
He explained to AFP that the project would “benefit people of all origins, unlike the current reference genome, which does not reflect the diversity of humanity”.
The pangenome represents “a milestone in human genetics” but also a challenge, recalled two American experts, Arya Masseret and Melissa Zimrek, quoted in Nature.
Beyond adding sequences from underrepresented groups, adoption of this new repository will require training from scientists.
In any case, they estimate, “this will help identify genetic variants that affect physical and physiological traits and – hopefully – lead to health improvements for many people.”