Surviving the last Ice Age may have come with more than just a shorter stature, it could have also increased the risks of developing osteoarthritis. This was all reportedly brought about by a single gene mutation.
Shorter Stature, Higher Osteoarthritis Risks
Modern humans are believed to have migrated out of Africa and towards Asia and Europe sometime in between 50,000 to 100,000 years ago, during the last Ice Age. As they did so, they had to face colder temperatures.
This latest research suggests that they were able to survive and conquer these temperature changes thanks to a single mutation, one that led to two changes. A resulting genetic modification led to shorter limbs and, in turn, to smaller people. However, the other result was a higher risk of suffering from osteoarthritis as one ages.
The study team explains that the shorter limbs presented several advantages in the colder weather. They are believed to withstand frostbite better, as fewer extremities and less skin are exposed to the cold. The stouter stature also seemingly reduces the risks of breaking bones by slipping on ice or from similar actions.
However, the GDF5 gene mutation also brought with it a higher incidence of osteoarthritis. GDF5 is a gene involved in joint formation and bone growth. Osteoarthritis is a condition that causes stiffness and pain in joints. In humans, this GDF5 mutation was tied to a 1.2 to 1.8 times higher risk of developing this condition.
“[…] even though it only increases each person’s risk by less than twofold, it’s likely responsible for millions of cases of arthritis around the globe,” states David Kingsley, a Stanford professor of developmental biology part of the study.
The research team considers that the risks of developing arthritis must have still been lower than the immediate ones brought by frostbite and the cold weather. Half of the people in Asia and Europe seemingly present this mutation, while in Africa, it is relatively rare.
Prof. Kingsley and his colleagues believe that their findings may have practical implications in the world of medicine as they could show a genetic component to the installation of arthritis.
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