Hepcidin, transferrin (exon 7), and hemochromatosis genotyping suggests that haplotype block analysis is the best strategy for predicting iron deficiency phenotype in women

Abstract

Strategies to draw associations between disease, genes and nutrients include the investigation of mutations and/or haplotypes. We studied the relationship between certain mutations in hepcidin (HAMP, exon 1, 2 and 3), transferrin (Tf, exon 7), and hemochromatosis (HFE, H63D and C282Y) genes,aswellastheirassociationsinhaplotypes,andirondeficiency,withorwithoutanemia,inyoung women. One hundred and sixty-two young, menstruating women were recruited. Hemoglobin (Hb [g/ dL]), ferritin (Ft [μg/L]), total iron binding capacity, Tf saturation, hematocrit, and mean corpuscular volume were determined, and subjects were divided in 3 iron status groups: sufficient (Hb ≥12, Ft ≥20; n = 63), deficient (Hb ≥12, Ft b20 or Hb b12, Ft ≥20; n = 77), and deficient-anemic (Hb b12, Ft b20; n = 22). Mutations in the HAMP gene were detected by means of single strand conformational polymorphism analysis, in exon 7 of the Tf gene using DNA sequencing, whereas C282Yand H63D mutations in theHFEgene were detected using restriction enzymes. Among the iron-deficient women, 8 were G277S/L247L-heterozygous (except 1 L247L homozygote), and 1 was I7V-heterozygous for the mutation in the HAMP gene. Three iron-deficient, anemic women were G277S/L247L/H63Dheterozygous (except 1 H63D homozygote), and1 was I7V-heterozygous. Two iron-sufficientfemales were G277S/L247L/H63D-heterozygous, 1 was G277S/L247L/H268H-heterozygous, and 2 were G277S/L247L-heterozygous. In conclusion, (1) the iron-deficient anemic group presented the highest proportion of subjects carrying mutations; (2) there are 3 possible haplotypes: G277S /L247L, G277S/ L247L/H63D, and G277S/L247L/H268H, nonrestricted to any iron status; and (3) analysis of haplotype blocks is the best strategy to associate genes and iron deficiency. © 2007 Elsevier Inc. All rights reserved.