Genetic evolution seen in peoples living at high altitudes

People living at some of the world's highest elevations seem to have evolved to cope with the thinner air, a U.S.-led genetics study suggests.

A team of researchers led by scientists at the University of California, Berkeley, has pinpointed a gene, BHLHE41, that appears responsible for high-altitude Ethiopians' ability to adapt to low-oxygen environments, the Los Angeles Times reported Monday.

People not acclimatized to high elevations can experience shortness of breath and other symptoms of "hypobaric hypoxia" due to low pressure and oxygen, the researches said.

"Fertility levels drop and birth weights are low in individuals who are not genetically adapted to high elevations," Berkeley postdoctoral researcher Emilia Huerta-Sanchez said.

But people long settled in places at extremely high altitude like the Tibetan and Andean plateaus and the Ethiopian highlands seem not to suffer the same effects, she said.

A study of Ethiopians living at high altitudes found a version of one gene, BHLHE41, at a higher frequency than in populations living lower down, the researchers said, strongly suggesting a genetic adaptation to living up high.

BHLHE41 interacts with a key protein to regulate the body's response to low oxygen, researchers said.