Hereditary hemochromatosis (HH) is an autosomal recessive disease characterized by excess iron. People with polymorphisms in the HFE gene (H63D and C282Y) may develop inflammatory processes resulting from changes in iron metabolism. The ability of the HFE protein to make connections with transferrin receptors, located on cell membranes, allows it to help control the absorption of iron in the body. This work sought to investigate the frequency of HFE gene variants in a sample from the city of São José do Rio Preto, SP, Brazil.

DNA samples from 105 people were subjected to molecular analysis to confirm mutations in the HFE gene (H63D and C282Y), using PCR-RFLP. The group was separated by male and female gender, age group of 10 in 10 years, and ethnic groups. Statistical analyzes were performed using the IBM SPSS Statistics 20 software and data were presented as percentages, with a significance level of 0.05. The associations between the wild-type homozygote, heterozygote, and mutant homozygote genotypes for each mutation were tested by the Chi-Square test. Then, the allele frequencies in the genotypes were calculated. Fisher's exact test was performed to verify the association between gender, age group, and ethnicity with mutations in the HFE gene.

The sample included: 55 men (52.38%) and 50 women (47.62%), with ages ranging from 18 to 62 years, with an average of 30 years. A total of 210 alleles were evaluated and for the H63D mutation, 78 wild-type homozygotes, 26 heterozygotes, and 1 mutant homozygote were found. For the C282Y mutation, 99 wild-type homozygotes, 6 heterozygotes and no mutant homozygote were found. Allelic frequency analysis indicated the occurrence of significant differences between wild-type homozygous, heterozygous, and mutant homozygous genotypes for the mutations (p < 0.05). Fisher's exact test indicated no association between gender, age, and ethnicity for the H63D and C282Y polymorphisms (p > 0.05). The heterozygous genotype for H63D was more frequent in men (15-14%) than women 11 (10%). For C282Y equal frequencies (3-3%) were found for heterozygosity between men and women. H63D heterozygosity was more frequent in Caucasians (22-21%). In African-derived, only one individual was heterozygous for H63D.

The frequency of HH genotypes varies among different populations. The low incidence or absence of homozygous alleles is due to the different degrees of miscegenation in the formation of the Brazilian population. The H63D mutation is an important marker for the Brazilian population, being frequent in Africa, although it has low phenotypic expression. The C282Y is predominantly associated with homozygosity for clinical cases, however, it is rare in African populations and frequent in Caucasians. Our results corroborate the data in the literature, with a predominance of the H63D mutation in Caucasians, African-derived, and Afro-descendants, and C282Y in Caucasians.

The frequency of H63D and C282Y polymorphisms in the HFE gene showed a higher occurrence of heterozygotes for H63D in this population group. Studies to characterize HH are needed to devise strategies for effective support to patients and, therefore, improve quality of life.