Prevalence of HFE mutations in upper Northern Italy: study of 1132 unrelated blood donors.

BACKGROUND: In the Italian general population, prevalence of C282Y is lower than in Northern European countries. We hypothesised a higher prevalence of C282Y in Northern than in Central and Southern Italy. We previously identified a nonsense mutation (W169X) in haemochromatosis probands originating from a Northern Italian region (Brianza). AIM: To define the prevalence of HFE mutations in that region. Subjects and methods. A total of 1132 unrelated blood donors from the Blood Banks of Monza and Merate were investigated for C282Y, H63D, S65C and W169X mutations by PCR-restriction assays. A total of 300 were also tested for rare HFE and TFR2 mutations by reverse-hybridization test strips. RESULTS: Two C282Y homozygotes, eight C282Y/H63D compound heterozygotes, 27 H63D homozygotes and one W169X heterozygote were found. The allele frequencies of C282Y, H63D, S65C, and W169X were 3.2, 13.4, 1.3, and 0.04%, respectively. CONCLUSIONS: Our results confirm the existence of a decreasing frequency of C282Y allele from upper to lower Northern Italy. This difference is probably related to the larger Celtic component of upper Northern Italian populations in which screening studies for haemochromatosis may even be cost effective. W169X, due to its severity, should be looked for in all haemochromatosis patients of Northern ancestry with an incomplete HFE genotype.