Effect of HFE Gene Mutations on Iron Metabolism of Beta-Thalassemia Carriers

The human hemochromatosis protein HFE is encoded by the HFE gene and participates in iron regulation. The aim of this study was to detect the most frequent HFE gene mutations in a control population and in β-thalassemia trait (BTT) carriers, and to study their relationship with iron metabolism. Total blood count, hemoglobin electrophoresis at alkaline pH, HbA2 quantification, iron (Fe), total Fe binding capacity and ferritin were assayed. HFE gene mutations were analyzed by real-time PCR. A total of 119 individuals (69 normal and 50 BTT) were examined. In the control group, 9% (6/69) presented a codon 282 heterozygous mutation (C282Y), and 19% a codon 63 mutation (H63D) (13/69, 11 heterozygotes and 2 homozygotes). In the BTT group, 3 carriers (6%) were heterozygous for C282Y, 14 (28%) for H63D, 1 (2%) for a codon 65 mutation and 1 (2%) was H63D and C282Y double heterozygous. Control group Fe metabolism did not show significant differences (p > 0.05) according to whether or not they carried an HFE gene mutation; while the BTT group with and without HFE mutation showed higher Fe and ferritin than the control group (p < 0.05). However, no increases in iron parameters were detected in BTT carriers that simultaneously exhibited an H63D mutation compared to BTT subjects without a mutation. Therefore, the iron metabolism alterations observed in BTT carriers could not be attributed to the presence of HFE gene mutations. It is likely that BTT individuals have other genetic modifiers that affect their iron balance.

Investigation of correlation between H63D and C282Y mutations in HFE gene and serum Ferritin level in beta-thalassemia major patients

INTRODUCTION

Mutations in the HFE gene have been shown to be associated with hemochromatosis which is observed in beta-thalassemia major. In this study, we determined the HFE gene mutations (C282Y and H63D) among b-thalassemia major patients to investigate the effect of these mutations on serum Ferritin levels.

MATERIAL AND METHODS

In this cross-sectional study, a total of 105 b-thalassemia subjects with a history of regular blood transfusion were selected. They divided into two distinct groups according cut off 1000ng/ml of serum Ferritin levels. The HFE gene mutant allele detected by RFLP-PCR.

RESULTS

Of 105 thalassemia patients, 29 patients (14 male and 15 female) were heterozygote for H63D mutation, and just one male was homozygote, but for C282Y mutation just one heterozygote and one homozygote was detected, and overall 31% had coexistence of b-thal and HFE gene mutations. As expected, Ferritin levels significantly differed between groups (P=0.001).

CONCLUSION

The impact of detection of HFE mutations could prognosis the likelihood of iron overload in multi-transfused patients, and allowing early diagnosis and proper management to overcome complications of iron overload in beta-thalassemia patients.

Late-onset Hemochromatosis: Co-inheritance of β-thalassemia and Hereditary Hemochromatosis in a Chinese Family: A Case Report and Epidemiological Analysis of Diverse Populations

Hereditary hemochromatosis and β-thalassemia can both result in the inappropriately low production of the hormone hepcidin, which leads to an increase in intestinal absorption and excessive iron deposition in the parenchymal cells. To the best of our knowledge, there have been no reports on the coexistence of the two disorders in China. We herein report a case in a Chinese who presented with late-onset hepatic cirrhosis with hereditary hemochromatosis and β-thalassemia. We analyzed the pedigree of the two disorders and the iron status in his family members. Our case supports that a heterozygous H63D mutation can interact with β-thalassemia, leading to late-onset hemochromatosis.

The Correlation of Cardiac and Hepatic Hemosiderosis as Measured by T2*MRI Technique with Ferritin Levels and Hemochromatosis Gene Mutations in Iranian Patients with Beta Thalassemia Major

Objectives

Organ-specific hemosiderosis and iron overload complications are more serious and more frequent in some patients with beta thalassemia major (BTM) compared with others. We investigated whether coinheritance of HFE H63D or C282Y gene mutations in patients with BTM contributes to the phenotypic variation of iron overload complications and assessed the correlation of cardiac and hepatic hemosiderosis with plasma ferritin levels.

Methods

We studied 60 patients with BTM with a mean age of 17.5±9.1 years from the Northwest of Iran. HFE gene mutations were analyzed using the polymerase chain reaction-restriction fragment length polymorphism method. Cardiac and hepatic hemosiderosis was assessed using T2*magnetic resonance imaging (MRI). Ferritin levels were measured using the enzyme immunoassay method.

Results

Ferritin levels showed a strong inverse correlation with hepatic T2*MRI values (r = -0.631, p = 0.001) but a poor correlation with cardiac T2*MRI values (r = -0.297, p = 0.044). The correlation between cardiac T2*MRI values and hepatic T2*MRI values was poor and insignificant (r = 0.287, p = 0.058). Genotype and allele distribution of HFE H63D and C282Y mutation did not differ significantly between patients with and without hepatic or cardiac hemosiderosis (p > 0.050). However, carriers of HFE 63D allele had significantly higher ferritin levels compared with non-carriers (1 903±993 vs. 992±683, p < 0.001).

Conclusions

Cardiac T2*MRI values showed a poor correlation with hepatic T2*MRI values and ferritin levels. Accurate assessment of cardiac iron overload in patients with BTM can only be done using the T2*MRI technique. Additionally, HFE H63D is a significant determinant factor for elevated ferritin levels in BTM patients.