Phenotype and HFE genotype in a population with abnormal iron markers recruited from an Endocrinology Department

The aim of this study was to describe HFE genotype in a population of patients with altered iron markers recruited in an Endocrinology Department and to define the possible phenotype-genotype relationships.

A total of 156 patients with high serum ferritin concentrations (>300 ng/ml) or transferrin saturation (>45%) (I group), and a control group of 106 healthy subjects (C group) underwent HFE genotyping (classical C282Y and H63D mutations). We also examined the main genetic features of subgroups in I according to the presence (D) or the absence (ND) of diabetes.

(1) The genotypes were significantly different in the I and C groups (P<0.001), with an increased frequency of major 282Y allele in the I group (35% vs 7.5%), but not of minor 63D allele (17 vs 18.5%). (2) The genotype of D and ND groups also differed (P<0.0001), with a lower frequency of C282 heterozygosity (P<0.0001) in the D group, and a higher prevalence of H63D heterozygosity in the D vs ND groups (P<0.01). (3) The phenotypic comparison of D and ND groups also showed a higher mean body mass index, age, and serum ferritin concentration, as well as an increased proportion of males with increased liver enzymes in the D group.

This population harboring abnormal iron markers had a different HFE genotype and a higher 282Y allele frequency than the control population. This suggests that blood iron markers could be checked in etiological investigations of metabolic disturbances to identify patients who should undergo genotyping, since approximately 20% were diagnosed with C282Y homozygosity.