Hereditary hemochromatosis is a deadly, but easily treatable disease that affects individuals of Northern European ancestry. It is caused by the excess absorption of iron from the diet. This iron can’t be excreted, and builds up in the body eventually leading to organ damage.
A common mutation in the HFE gene
Defective versions of the HFE gene are the leading cause of hereditary hemochromatosis. About 1 in 9 people of European ancestry carry at least one defective copy of HFE. Approximately 1 in 200 carry two defective copies of HFE, and are at increased risk of hemochromatosis.
The most common HFE variant associated with hemochromatosis is the C282Y mutation. Almost 85 to 90% of clinically affected individuals test positive for this mutation.
Following the Vikings
The striking prevalence of this mutation in people of European ancestry, led researchers to investigate the origin and spread of the C282Y mutation. Population studies show a very interesting and distinct distribution pattern for the C282Y mutation.
Established Viking settlements in Northern European regions have the highest frequencies of this mutation. Up to 9.1% of individuals in these regions carry the C282Y mutation, with the highest frequencies detected in the coastal populations.
The allele frequencies are lower at 3.1 to 4.8% in central Europe, and significantly lower (less than 3.1%) in regions of Europe that the Vikings did not conquer or inhabit for extended periods (such as the Mediterranean).
The “Viking Hypothesis”
These frequency studies estimate that the C282Y mutation appeared approximately 60 to 70 generations ago.
Assuming that each generation is 20 to 25 years, that would place the origin of this mutation at approximately 1200 to 1750 years ago. It then appears to have rapidly spread along the coastline of Europe, and out from Northern and Western Europe.
The timing and pattern of this spread has a very close correlation to the migration of Vikings. Hence, the development of “Viking Hypothesis”. This hypothesis proposes that the C282Y mutation first occurred in a Viking, and spread via his descendants throughout Europe, as the Vikings conquered and settled in different areas.
Are you at risk?
Does your Viking ancestry put you at risk of hemochromatosis? Take the DNA Hemochromatosis Test to find out if you have inherited the “Viking gene” and are at risk of developing this common disease.