Human DNA map now includes ancestry-related genetic variations

A draft of a new map of the human genome, collated from multiple individuals, has enabled the identification of new genetic variants that had been previously difficult, or impossible, to find.

The map, named the human 'pangenome', was published in Nature alongside papers describing its initial applications and resources for use by researchers. This latest version of the human reference genome has the potential to transform medical research by leading to the development of new drugs and treatments for a broader range of people.

'The human pangenome reference will enable us to represent tens of thousands of novel genomic variants in regions of the genome that were previously inaccessible', said Wen-Wei Liao, the co-first author of the paper, a PhD student in molecular genetics and genomics at Washington University in St Louis who is currently conducting research at Yale University, Connecticut. 'With a pangenome reference, we can accelerate clinical research by improving our understanding of the link between genes and disease traits.'

Genetics research relies on reference genomes, which are 'standard' genetic sequences to which new genomes are compared in order to find alterations which may shed light on various traits such as diseases. A draft of the first human reference genome was completed over twenty years ago and its current version is widely applied.

However, this reference genome was developed using genetic sequences from only twenty people, with 70 percent of it based on only one individual, an American man with European-African ancestry. Consequently, this introduced biases due to how specific the current reference genome is.

This has a particular effect on African populations since this is where there is the greatest amount of genetic diversity, thereby making subsequent findings less applicable in these populations.

The new human pangenome was developed using the full genomes of 47 individuals, with 24 from Africa and 16 from the Americas, which were integrated using advanced computational graph-building techniques. These results have been made publicly available, along with resources that enable researchers to use it in a similar way to the current linear reference genomes.

'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' said David Adelson, a professor of bioinformatics and computational genetics at the University of Adelaide, Australia.

He added, 'This paper heralds a new age of genetic diagnosis, that will benefit people from all ancestries, unlike our current reference genome that does not reflect all the diversity of humanity.'