Over 80%, of Caucasian patients with hereditary haemochromatosis are homozygotes for a C282Y mutation in the HFE gene on chromosome 6. Recent evidence suggests that a genetic factor may also be involved in the pathogenesis of African iron overload, although the locus has not been described. PCR analysis of DNA from 25 southern Africans, identified by segregation analysis as having a high probability of carrying the putative African iron-loading gene, failed to identify any subjects with the C282Y mutation. The possible genetic defect in African iron overload appears to be different from that described in most cases of hereditary haemochromatosis in Caucasians.