Less is more: Tibetans thrive on 'roof of the world' due to missing genome, study suggests

Tibetan highlanders may have adapted to their high altitude environment by breeding out parts of the genetic code over thousands of years, according to a new Chinese study.

This genetic mutation stabilised their red blood cell count, thus keeping altitude sickness, and more deadly side effects linked to great heights, at bay, the scientists believe.

Tibetans have lived on the roof of the world for thousands of years, an extreme environment where snow capped peaks tower over 7,000 metres, and Himalayan Sherpas earn a living by ferrying loads up mountains.

Usually, red blood cells spike at higher elevations, an emergency response that increases the lungs’ ability to absorb oxygen from the air.

But most Tibetans have “normal” readings, and now scientists think a mutation dubbed TED, short for Tibetan-enriched deletion, is the key. 

Data analysis showed that the mutation caused the deletion of a specific genome section near the gene EPAS1.

“TED might have played a critical role in the high altitude adaptation of Tibetans,” said professor Xu Shuhua, lead scientist of the study.