When one is not enough, go for 47. That’s the takeaway from a huge international team of researchers creating the ‘pangenome’ – genomic sequences from 47 people from diverse ancestries – to be able to better understand the breadth of the human race.
According to geneticists, this pangenome set of studies is a step forward in mapping the diversity of the human genetic code.
“There is no such thing as ‘normal’ genes,” says QUT clinical geneticist, Associate Professor Michael Gabbett.
“Humans are wonderfully diverse creatures, with each individual having their own unique collection of genetic variants.
“A single reference sequence cannot and does not capture the extraordinary genetic diversity of people around the globe.”
The first human genome was mapped – as part of the Human Genome Project – in the early 2000s.
The first genome, painstakingly put together at a cost of over $3 billion dollars – was not actually one individual’s genome, but a mix of a handful of genomes, all smooshed into one. This single genome was an absolute triumph at the time, but it didn’t reveal everything. One of the biologists who helped lead the effort suggested that the genome could be summed up with “bought the book; hard to read.”
Genetics has moved on since 2003, and a much wider variety of humans were required to allow the genome to continue to be useful.
A series of papers in Nature have now released the ‘pangenome’ – mapping the genomes of 47 ancestrally diverse individuals, which adds 119 million base pairs and 1,115 gene duplication mutations to the original reference human genome.
“With the pangenome we can now look for genetic changes across many individuals and ultimately the pangenome will grow to include information from thousands and perhaps millions of genome sequences. This means our ability to use genetic information for diagnosis will increase enormously,” says University of Adelaide bioinformatician Professor David Adelson.
“With the current pangenome from only 45 humans, the accuracy of detection to find genetic changes has gone up by 34 percent and the number of large, difficult-to-detect changes we now know about has gone up by over 100 percent!”
You can see the summary paper of the research published in Nature.