Haemochromatosis in patients with beta-thalassaemia trait.

Severe iron overload has been reported in patients with the beta-thalassaemia trait. Studies performed before the discovery of the haemochromatosis gene (HFE) have yielded conflicting results: some suggest that iron overload might arise from the interaction of the beta-thalassaemia trait with heterozygosity for haemochromatosis, some with homozygosity for haemochromatosis and others that it was unrelated to haemochromatosis. We have studied the clinical phenotype, iron indices and HFE genotypes of 22 unrelated patients with the beta-thalassaemia trait and haemochromatosis, the inheritance of chromosome 6p and 1q haplotypes in families of non-homozygous C282Y probands and serum measures of iron status in relatives heterozygous for C282Y with or without the beta-thalassaemia trait. We demonstrate that the beta-thalassaemia trait aggravates the clinical picture of C282Y homozygotes, favouring higher rates of iron accumulation and the development of severe iron-related complications. We suggest that the coexistence of the beta-thalassaemia trait might also increase the risk of iron overload in patients with HFE genotypes at a mild risk of haemochromatosis. Our findings do not support the hypothesis that the association of the beta-thalassaemia trait with a single C282Y or H63D allele might lead to iron overload and suggest that other non-HFE-related inherited factors are present in haemochromatosis patients with incomplete HFE genotypes.