Impact of Genotype of Beta Globin Gene on Hepatic and Myocardial Iron Content in Egyptian Patients with Beta Thalassemia.

Abstract

Iron overload causes most of the mortality and morbidity associated with thalassemia. Excess iron deposits primarily in the liver, but once a threshold level is reached, iron loading may occur in other tissues such as the heart. Magnetic resonance imaging is a well established technique to noninvasively quantify myocardial and liver iron content. More than 300 disease-causing mutations have been identified. We aimed to determine the impact of genotype on liver iron content in patients with beta thalassemia. Cross sectional study was carried on 73 patients with beta thalassemia. MRI liver and heart was performed to determine hepatic and myocardial iron overload. Genotyping was determined by DNA sequencing technique. The mean liver iron content was 17.4mg/g dw and mean cardiac T2* was 25.5ms in our patients. Patients with β0β0 were associated with significantly higher liver and myocardial iron content compared to those with β0β+ and β+β+ genotypes. There was a clear association between genotype and both hepatic and myocardial iron overload. Patients with β0β0 had significantly higher liver and heart iron content compared to those with β0β+ and β+β+ genotypes. Liver iron content was strongly correlated to serum ferritin levels and myocardial iron overload.