“ Viking Disease ” , or Dupuytren ’s contracture , is an strange upset where the tissue under the hide of a hand becomes thicker and less flexible , often allow one or more fingers in a permanently bent status . For a tenacious time , researchers cognise the precondition was more coarse in northerly Europeans than in those with African descent , but now a fresh cogitation has show that it may be tie in toNeanderthalheritage .

The condition was named after the Gallic surgeon , Guillaume Dupuytren , who first described the mechanisms that led to the characteristic deformations in the early 1830s . It usually starts with small hard nodules under the skin of the ribbon which , over clock time , thicken and frame cords that pull the fingerbreadth into a flexed position that can not be straighten . Although it can impact any finger , it is commonly seen in the ring and little digit .

The exact make ofDupuytren ’s contractureare currently unknown , but scientists have previously identified several risk factors that seem to mold its development . These include an individual ’s age , whether they fume , drink in lots of alcoholic drink , have diabetes or epilepsy , and whether there is a family history of the condition . This latter cistron has been given more system of weights by enquiry conducted over the last few decades . For instance , in 2015 , aDanish studyfound that Dupuytren ’s contracture had 80 percent heritability , which precede them to conclude that genetics played an important function in the evolution of the status .

Interestingly , it seems it is more uncouth in people with northerly European ancestry than those of primarily African descent . Onestudy , guide in 1999 , found that there was a 30 percent prevalence among Norwegians over the age of 60 . It was this geographical distribution that lead to its nickname – “ Viking disease ” .

There is a distinct geographic conflict in how muchgenetic ancestrymodern humans have from antediluvian specie , such as Neanderthals and Denisovans . It seems that those who come from sub - Saharan African land have very little hereditary links to Neanderthals and Denisovans who tend to live in Europe and Asia until around 42,000 years ago . In line , multitude who are from outside of Africa have far higher grounds of transmissible inheritance from these nonextant human species . These regional differences brought on by archaic gene variations can contribute to specific characteristics as well as disease preponderance within sure populations .

It was this disparity in the geographic distribution of the disease that led Hugo Zeberg , helper prof at the Department of Physiology and Pharmacology , Karolinska Institutet , and his team to investigate its genic origins .

“ Since Dupuytren ’s contracture is rarely seen in individuals of African descent , we wondered whether gene variant from Neanderthals can part explain why people outside of Africa are affected ” , Zeberg said in astatement .

The team used information from 653,751 people – 7,871 had Dupuytren ’s contracture while the persist 645,880 were a command population . This entropy was drawn from theUK Biobank , theFinnGen R7collection , and theMichigan Genomics Initiative .

They found 61 genome - wide significant version associated with Dupuytren ’s contracture , three of which were Neandertal in origin , including the 2nd and third most strongly link I . This led the researchers to conclude that Neanderthal ancestry is a pregnant factor in the prevalence of Dupuytren ’s contracture in Europeans today .

“ Present - day genomes contain haplotype that are similar to archaic genome ” , Zeberg and his colleagues wrote , “ both because they inherit haplotype from populations ancestral to both advanced humans and archaic humans and because modern humans interbred with archaic grouping when they met less than 100,000 years ago . ”

The results go a farsighted way of life to show the importance of reckon the use our genetical heritage may have had on disease prevalence . However , the squad stress that these connections should not be taken too far .

“ This is a case where the confluence with Neanderthals has affected who suffers from illness , ” Zeberg summate , “ although we should not overdo the connection between Neanderthals and Vikings . ”

The paper is bring out inMolecular Biology and Evolution .