HFE gene mutations an Apulian population: allele frequencies

Hereditary hemochromatosis (HH) is an autosomal recessive trait regarding iron metabolism frequently found in Caucasian populations. The C282Y mutation of the HFE gene, held responsible for HH, has been identified as the major genetic basis for the phenotypic expression of HH whereas two additional mutations of the HFE H63D and S65C gene appear to be associated with a milder form of HH. A high allele frequency of C282Y and H63D has been reported in Northern European populations. In Italy, the overall allele frequency was 0.5% for the C282Y mutation, 12.6% for the H63D mutation and 1.1% for the S65C mutation. In this study, we evaluated the allele frequency of the three principal HFE mutations (C282Y, H63D, S65C) together with eight additional mutations (V53M, H63H, Q127H, E168Q, E168stop, W169stop, V59M, Q238P) in 500 healthy Apulian subjects. No subject homozygous for the C282Y mutation was found while 3% of subjects were heterozygous for this mutation. Heterozygosity and homozygosity for the H63D mutation were 26 and 1%, respectively. Only five subjects were heterozygous for the S65C mutation. Overall, the allele frequency was 1.5% for C282Y, 14% for H63D, 0.5% for S65C and 0% for the other mutations. The transferrin saturation (TS) was significantly higher in subjects heterozygous for the H63D mutations with respect to subjects with a normal genotype, though all were within the normal range. No statistically significant difference in the allele frequency was noted in the Apulian population compared to that in Northern and Southern Italy.