[A] single string of As, Ts, Cs and Gs eventually became the first human reference genome. Since its publication in 2003, the reference has revolutionised genome sequencing and helped scientists find thousands of disease-causing mutations. Yet at its core is a somewhat ironic problem: the code meant to represent the human species is mostly based on just one man from Buffalo, New York.
Though humans are very similar, “One person is not representative of the world,” says Pui-Yan Kwok, a specialist in genome analysis based at University of California, San Francisco and Academia Sinica in Taiwan. As a result, most genome sequencing is fundamentally biased.
This bias limits the kind of genetic variation that can be detected, leaving some patients without diagnoses and potentially without proper treatment. What is more, people who share less ancestry with the man from Buffalo will probably benefit less from the incoming era of precision medicine, which promises to tailor healthcare to individuals.
To combat this, researchers have started to assemble reference genomes for specific countries, including South Korea, Japan, Sweden, Denmark and the United Arab Emirates. They hope this will serve their populations better, but critics worry it could turn migrants into second-class citizens in their healthcare systems. Now, a huge new project is offering a different solution with the aim to represent global diversity: a human pangenome.
