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Neanderthal gene variant lowers muscle enzyme activity in modern humans

The enzyme AMPD1 plays a key role in muscle energy production and normal muscular function. Loss of AMPD1 activity due to genetic mutations is the most common cause of metabolic myopathy in Europeans, occurring at a frequency of 9% to 14%.

In a study in Nature Communications, researchers compared ancient Neanderthal DNA with modern human genomes and found that all Neanderthals carried a specific AMPD1 variant absent in other species. Laboratory-produced enzymes with this variant showed a 25% reduction in AMPD1 activity. When introduced into genetically engineered mice, the reduction reached 80% in muscle tissue, impairing enzyme function.

The study also revealed that modern humans inherited this variant through interbreeding with Neanderthals, who inhabited Europe and Western Asia before encountering modern humans about 50,000 years ago. Today, individuals of non-African descent carry roughly 1% to 2% Neanderthal DNA.

The Neanderthal AMPD1 variant is carried by 2% to 8% of Europeans today, suggesting that it is generally tolerated.

"Strikingly, most individuals who carry the variant do not experience significant health issues. However, the enzyme appears to play an important role in athletic performance," explains Dominik Macak, the study's first author. An analysis of more than 1,000 elite athletes across various sports revealed that individuals who carry a non-functional AMPD1 are less likely to become top-level athletes.

"Carrying a broken AMPD1 enzyme, the likelihood of reaching athletic performance is reduced by half," Macak adds.

In summary, although AMPD1 activity appears to have only moderate relevance in contemporary Western societies, it is important under extreme physical conditions, such as those experienced by athletes. The researchers emphasize the importance of studying genetic variants in their physiological and evolutionary contexts in order to understand their biological effects.

"It's possible that cultural and technological advances in both modern humans and Neanderthals reduced the need for extreme muscle performance," says senior author Hugo Zeberg.

Understanding how ancient gene variants affect human physiology today can provide valuable insights into health, performance, and genetic diversity.