Significance of linkage disequilibrium between mutation C282Y and a MseI polymorphism in population screening and DNA diagnosis of hemochromatosis

An increasing number of studies demonstrate a lack of phenotypic expression in subjects found to be homozygous for the common hereditary hemochromatosis (HH) mutation, C282Y In this study the impact of possible overestimation of C282Y homozygosity, as a consequence of a MseI polymorphism identified in intron 4 of the HFE gene, was investigated in South African subjects. Utilization of a modified polymerase chain reaction (PCR)-based assay highlighted the potential implications with respect to genotype/phenotype correlation studies, particularly in the general population. Mistyping rather than lack of disease association provides a plausible explanation for the phenomenon of C282Y homozygosity without iron overload. Reassessment of C282Y mutation status in such cases may result in justified population screening in HH.