Hereditary hemochromatosis is a deadly but treatable disease, found predominantly in individuals of European descent. The gene mutation most commonly associated with hemochromatosis is the C282Y mutation in the HFE gene. Almost 85 to 90% of all individuals who are clinically affected with hemochromatosis, test positive for the C282Y mutation. The strong genetic association of hemochromatosis with the C282Y mutation, and the striking prevalence of this mutation in individuals of European ancestry, has led researchers to investigate the origin and spread of the C282Y HFE mutation.
The population studies show a very interesting and distinct distribution pattern for the C282Y mutation across Europe. Regions in Northern Europe, that were established Viking homelands and settlements, have the highest frequencies (5.1-9.1%) of the C282Y mutation. The coastal populations, within each of these areas, typically have the highest C282Y allele frequencies. In Central Europe, the C282Y allele frequencies are lower at 3.1-4.8% and significantly lower (0-3.1%) in regions of Europe that the Vikings did not conquer or inhabit for extended periods (including the Mediterranean and Russia).
Based on these C282Y allele frequency studies, it has been estimated that the C282Y mutation appeared approximately 60-70 generations ago. Assuming that each generation is 20 to 25 years, that would place the origin of this mutation to approximately 1200 to 1750 years ago, with subsequent rapid spread along the coastline of Europe and disseminating from Northern and Western Europe. The timing and pattern of spread of this mutation has a very close correlation to the migration of Vikings, resulting in the “Viking hypothesis” for the C282Y mutation. This hypothesis is that the C282Y HFE mutation first occurred in a Viking and spread via his descendants throughout Europe as the Vikings conquered and settled in different areas.
Milman N and Pedersen P (2003). Evidence that the Cys282Tyr mutation of the HFE gene originated from a population in Southern Scandinavia and spread with the Vikings. Clinical Genetics, 64(1): 36-47. DOI: 10.1034/j.1399-0004.2003.00083.x