Which mutation occurs in 80-85% of most hemochromatosis cases?

The C282Y mutation is the most prevalent mutation associated with hereditary hemochromatosis, accounting for 80-85% of cases. This mutation involves a substitution of tyrosine for cysteine at position 282 of the HFE protein, which is involved in iron regulation in the body. Individuals who are homozygous for the C282Y mutation have a significantly higher risk of developing iron overload and related complications due to impaired regulation of dietary iron absorption.

Given the high prevalence of this particular mutation in affected individuals, it reflects the genetic basis of the disease and its commonality in specific populations, particularly those of Northern European descent, where the mutation is more frequently observed. The other mutations listed, while they may contribute to hemochromatosis, do not occur with the same frequency or have as significant an impact on the overall disease presentation.