• The 40,000-year-old genetic inheritance bestowed on us by the Neanderthals was highlighted by a new study.
• Interbreeding with Homo sapiens helps to explain why millions can’t straighten their fingers.
• There is also a Neanderthal gene variant that increases the risk of somebody dying from COVID-19.

The 40,000-year-old genetic inheritance bestowed on us by the Neanderthals has been highlighted by a new study.

The new findings suggest that the risk of developing Dupuytren’s disease, sometimes called “Viking disease,” increases when a person has inherited DNA from Neanderthal ancestors. 

Researchers analyzed more than 7,000 people with Dupuytren’s disease —  a common condition particularly in northern Europe where people’s fingers are permanently bent — to examine genetic risk factors.

Also called Dupuytren’s contracture, it occurs when nodules appear in the ligaments beneath the skin of a person’s palm, according to The British Society for Surgery of the Hand, and it is more commonly developed by men than women later in life. 

The study found that three important genetic risk factors were inherited from Neanderthals, after conducting research with clinical groups in the US, the UK and Finland. 

“Since Dupuytren’s contracture is rarely seen in individuals of African descent, we wondered whether gene variants from Neanderthals can partly explain why people outside of Africa are affected,” Hugo Zeberg, who lead the study and a professor at the Karolinska Institute in Sweden, said in a statement. 

Up to about 30% of men over 60 years old suffer from this condition in northern Europe, the study published in the journal Molecular Biology and Evolution said. It is estimated to affect as many as two million people in the UK, per The Times. 

Just 7% of the human genome is unique to our species

Neanderthals lived in Europe and western Asia until about 40,000 years ago, when they were replaced by modern humans, according to the Karolinska Institute. The study evidences that “intermingling” from Neanderthals and our Homo sapiens ancestors is consequential in examining the prevalence of certain diseases, researchers said.

“This is a case where the meeting with Neanderthals has affected who suffers from illness,” Zeberg said. 

A similar study, for example, showed that a Neanderthal-inherited gene variant in modern humans may increase the risk of getting COVID. 

Other research has suggested the shape of a person’s nose may indicate whether they share DNA with our Neanderthal cousins, The Times recently reported. 

Scientists believe modern-day humans share a significant portion of genetic material with other human ancestors like Neanderthals and Denisovans, Insider previously reported. No more than 7% of the human genome is unique to Homo sapiens, according to a study published in the journal Science Advances.

Brain development and function are what sets Homo sapiens apart, experts explained. 

Anthropologists and scientists have previously also found evidence that Neanderthal and Denisovan relatives may have overlapped and mixed with modern human species across Europe and Asia.