Haemochromatosis gene mutation H63D is a risk factor for iron overload in Egyptian beta- thalassemic children

Abstract

Introduction: Iron overload is the main cause of morbidity and mortality in
patients with β-thalassemia. The Aim: The aim of this study was to evaluate the prevalence of genetic markers (HFE mutations C282Y and H63D) among Egyptian β-thalassemic
Children and its effect on their iron status. Patients and Methods: 59 β-thalassemic children attending the pediatric hematology clinic in Menoufiya University Hospital (23 thalassemia major, 23 thalassemia intermedia and13 thalassemia trait) with 50 apparently healthy,
Egyptian children (control group) were screened for the prevalence of these two mutations by digestion of PCR products (RFLP). Serum ferritin level was measured by ELISA.
Results: Neither carrier status for the C282Y allele nor homozygous status for the H63D allele were detected in any of the thalassemic children or the 50 controls. The H63D heterozygous state was detected in 15 (25.4%) thalassemic patients with an allele frequency of 12.71% and in 11 (22%) controls with an allele frequency of 11%. with no significant difference between the thalassemic groups and the controls. The prevalence of carriers for the H63D mutation was 26.1% with an allele frequency of 13.04% in patients with either β- thalassemia major or intermedia, while in β- thalassemia trait the prevalence of this mutation was 23.1% with an allele frequency of 11.54%. There were significant higher levels of the mean yearly serum ferritin in both β-thalassemia major and intermedia patients who are heterozygotes for the H63D mutation compared to those without this mutation. The mean serum ferritin levels were positively correlated with the age of the patients. On the other hand, the prevalence of iron -induced complications was not statistically different between patients carrying or not carrying this mutation (among TM and TI). Conclusions: There is no difference in the prevalence of H63D mutation between β-thalassemic patients and the normal children and the presence of a heterozygous H63D status and older age are two risk factors for iron overload in Egyptian β-thalassemic children
Abbreviations: RFLP= Restriction Fragment Length Polymorphism, HCV=Hepatitis C Virus, ALT = Alanine aminotransferase, AST =Aspartate aminotransferase

Keywords: Thalassemia, iron overload, hereditary hemochromatosis, HFE gene

Egyptian Journal of Medical Human Genetics Vol. 9 (2) 2008: pp. 149-160