Incidence of a clinically relevant H63D syndrome in carriers of a homozygous mutation of HFE gene H63D

H63D syndrome is a phenotype of a homozygous mutation of the HFE gene H63D, which is otherwise known to cause at most mild classical hemochromatosis. H63D syndrome leads to an iron overload in the body (especially in the brain, heart, liver, skin and male gonads) in the form of non-transferrin bound iron (NTBI) poisoning. Hallmark symptoms and causal factor for H63D syndrome is a mild hypotransferrinemia with transferrin saturation values >50%. H63D syndrome is an incurable multi-organ disease, leading to permanent disability. Our objective was to find out how many carriers of a homozygous H63D mutation develop H63D syndrome. For this purpose, we systematically evaluated the medical records of homozygous carriers of the mutation. We found the syndrome in about 10% of patients with a homozygous mutation. Since a homozygous mutation on the HFE gene H63D is relatively common, the results of our study suggest many undetected or misdiagnosed cases.