A new genome reference index could save the genetic diversity of all humans

It’s time for an update.

Derya Ozdemir
A new genome reference index could save the genetic diversity of all humans
The DNA molecule.Dr_Microbe/iStock

A team of scientists from all over the world has launched a new endeavor to develop a reference genome that captures the genetic diversity of all humans.

Called the Human Pangenome Project, the initiative aims to gather, organize, and make accessible a representation of all genetic diversity found in people.

Over the next five years, the scientists will work to sequence the genomes of 350 people from various populations. Eventually, they want to reach a point where they’ve sequenced thousands of genomes and captured as much human genetic diversity as possible, which could allow patients to undergo a DNA test in the future to reveal information about their genetic risk for different diseases and conditions.

On a quest to document the genomic diversity of the world  

In case you didn’t know, your genome is made up of 3.1 billion DNA molecules in sequence. While all human genomes are fairly similar in general, small differences in the sequences play a significant role in determining what makes each of us unique, and that can include susceptibility for disease.

A reference genome aids in describing those variations by mapping the location of genes and other genomic elements, which means it can be used by scientists to discover new genes, variations of existing genes, and other functional elements. It can also be used to communicate and compare findings with other scientists, which is what makes it so important.

However, most studies of the human genome have relied on samples from people of European ancestry, which complicates matters.

For example, a team of scientists announced a few weeks ago that they were able to finish decoding the last eight percent of a genome reference that represents a comprehensive map of a human genome. However, this reference genome is based on 20 individuals, with the majority of the sequence coming from a single person, which is why it doesn’t reflect the wonderful diversity of the world’s population.

While the human reference genome is the most widely used resource in human genetics, the researchers think it’s due for a big update.

Mapping a complete genome, error-free, from end to end

“We don’t want to have a (single) reference; we want to have many references that will capture human diversity,” Evan Eichler, a professor of genome sciences at the University of Washington School of Medicine in Seattle and a co-author of the paper, said. The Human Pangenome Project will attempt to overcome this hurdle by obtaining consent from groups who might be wary of efforts by Western scientists to sequence their population’s DNA and creating numerous complete reference genomes that represent hundreds of people from all around the world.

Some groups have rejected the proposal, while others have shown interest. However, they have stated that they want to do their own genome sequencing and make the data available as they see fit. The project is currently seeking to provide these communities with the technology required to do this research. 

Over the next five years, the researchers will utilize a painstaking procedure known as “long read” sequencing to map one full genome from end to end, error-free. 

This is just a beginning step with many obstacles littered along the way. However, the scientists’ laborious efforts may one day allow anyone on the globe to walk into a doctor’s office and have a DNA sample collected and sequenced to see their genetic risk for cardiovascular disease, diabetes, and other conditions, bringing us close to the future of human genetics.

The paper was published on April 20 in the journal Nature.

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