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Scientists have compiled a new draft human genome which better captures the genetic diversity of humanity.
The 'pangenome,' a new DNA sequence that combines the DNA of 47 people from all continents except Antarctica and Oceania, is now available. Scientists say that it will help us diagnose diseases, find new drugs and better understand genetic variations that cause ill health.
Geneticists used to use a single genome, which was based largely on one person, as the standard reference map when detecting genetic changes that lead to disease. It is likely that some genetic diversity has been missed between individuals and populations.
The director of the US National Human Genome Research Institute (which funded the project) Eric Green said at a press briefing that the pangenome represents a scientific achievement. It provides broader views of humanity's genetic blueprint and reveals remarkably more human diversity than the previous reference sequences.
Green stated that a high-quality human pangenome will help scientists and health professionals better understand the impact of genomic variants on health and disease. This will lead to a future where genomic medicine is beneficial for everyone.
Pangenome is still in draft form. It's a digital amalgamation that can be used for comparison, construction and study of other human genomes. Researchers aim to include 350 individuals by the middle 2024. Nature and its partners published several papers detailing the scientific milestone on Wednesday.
You can think of this as a road map for dropping off your children at school. Benjamin Schwessinger is an associate professor from The Australian National University, who was not involved in the project.
Schwessinger stated in a press release that 'this new approach of a "pan-genome" maps out these alternate routes that make humans so different from one another.
The human genome, which is 3.2 billion pairs long, is huge. Each person's DNA varies by only 0.4% on average. There are still many genetic differences that exist between people and populations.
The four base pairs of DNA - adenine, cytosine, guanine and thymine - form specific pairs. Their binding forms the DNA structure.
The genomic variation can be very small and consist of only a few base pairs of DNA, or large structural variants that are at least 50 base pair. These structural variants, which are larger in size, can have significant health implications. For example, they may affect the immune system's functioning.
The new reference includes more diverse genetic sequences, and adds 119 millions base pairs to a library of 3.2 milliards previously known base pair that makes up the human genome. This deepens our understanding of genetic diversity in humans and makes it more complete.
The pangenome reveals how variation affects genes, said Benedict Paten. He is an associate professor of Biomolecular Engineering at the University of California Santa Cruz and the associate director of the UC Santa Cruz Genomics Institute.
It also reveals a new biology...we're getting an improved picture of how some of most complex regions of genome vary. Paten explained that until now, we were largely unaware of the composition and rapid evolution of these regions.
The first draft of human genome was published in 2001, and it was not completed until 2022. The human genome has proven to be a valuable tool for researchers. It launched a new era of scientific discovery, technological innovations and genomic medicine. Karen Miga is an assistant professor at the University of California Santa Cruz's biomolecular Engineering department and the associate director of the UC Santa Cruz Genomics Institute.
Miga stated that 'understanding and cataloguing these differences will allow us understand how cells function, their biology, and how they work, as well understanding genetic differences, and how they contribute towards understanding human diseases'.
According to the NHGRI, the original human reference genome was primarily based on anonymous donors who responded to a Buffalo Evening News ad in March 23, 1997. One donor accounted for 70% of sequence.
The 47 anonymous individuals who were included in the pangenome first draft project are among the participants of the 1000 Genomes Project. This was a catalog of human genetic variations that was completed in 2015, and which includes a list of all the common ones. The team is currently recruiting individuals to represent populations that were not part of the 1000 Genomes Project. This includes people with Middle Eastern or African ancestry.
A Nature article published last year about the pangenome project stated that other projects to broaden genomic databases had 'often failed the mark' in showing respect for communities and indigenous people in low-income countries. They claim their samples and data were being used by scientists and institutions from richer countries.
The team wanted to avoid making any mistakes similar. Barbara Koenig said that ethical considerations, and the principle of justice, were key parts of the project.