8,000-Year-Old Mutation Helps Tibetans Survive Low-Oxygen Conditions

A single DNA base pair change, which dates back 8,000 years, explains how Tibetans manage to survive in thin air some 14,000 feet above sea-level.

The study was conducted by the University of Utah researchers and included over 90 participants from Tibet.

The researchers found that around 88 percent of Tibetans have a genetic variant of the gene EGLN1. The mutation is uncommon in populations living in lowland areas, according to the Sydney Morning Herald.

Oxygen at the Tibetan plateau is only about 60 percent of that at sea level. Related research has shown that a variant of EPAS1 gene variant has helped Tibetans survive at the roof of the world. A recent study had even suggested that the gene that helps Tibetans survive in the inhospitable conditions of the plateau came from ancient human cousin - Denisovan.

The current study found that a key mutation in the gene EGLN1 occurred some 8,000 years ago. Today, in a short interval of time, a majority of Tibetans carry this variant. Close relatives of the Tibetans who live at lower altitudes lack this mutation, suggesting that the variation is unique to people living in Tibet.

"These findings help us understand the unique aspects of Tibetan adaptation to high altitudes, and to better understand human evolution," said Josef Prchal, M.D., senior author and University of Utah professor of internal medicine, according to a news release.

According to researchers, people who do not carry the gene variation tend to suffer from heart problems at high altitudes as blood becomes thick in low-oxygen conditions. The EGLN1 variation along with other genetic changes helps Tibetans survive in thin air.

The study, "A genetic mechanism for Tibetan high-altitude adaptation", is published in the journal Nature Genetics.