الفهرس 
Beta-thalassemiaOnly 14 pages are availabe for public view
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Abstract
Beta-thalassemia is an inherited disorder caused by mutations in the beta-globin genes leading to a total lack or reduction in the synthesis of normal beta-globin chains. Patients with beta-thalassemia major present clinically with severe transfusion-dependent anemia together with other related complications.
Accelerated oxidative damage is one of the hallmarks in thalassemia major where the elevation in serum ferritin due to continuous blood transfusions promotes peroxidative damage in thalassemia patients. A decreased antioxidant level is found.
Single nucleotide polymorphism (SNP) is a variation of the DNA sequence in which a single nucleotide of the sequence has been altered. These highly abundant SNPs occur in every 1000 bases in the human genome.
MTHFR is the most critical enzyme in folate-metabolizing pathway, plays a key role in the remethylation process of homocysteine, also in de novo thymidine synthesis.
A C to T missense mutation at nucleotide 677 (C677T SNP) produces a thermolabile form of the enzyme associated with reduction in its activity due to alanine is converted to valine. This can lead to elevated homocysteine which acts as a prooxidant, generating free radicals by auto-oxidation, inducing lipid peroxidation, decreasing endothelial NO and causing endothelial cell damage. Several studies have demonstrated a relationship between the MTHFR C677T polymorphism and abnormal levels of oxidative stress markers.
polymorphism and oxidative changes among beta-thalassemia major patients.
This study was carried out on 80 subjects divided into two groups. Group1 include 60 thalassemic children patients. group 2 include 20 age and sex-matched healthy children as controls.
All studied individuals were subjected to the following: complete history taking as onset of transfusion, frequency of transfusion and complete blood count, serum ferritin, total antioxidant capacity, Genotyping for MTHFR C677T was done by (PCR-RFLP) technique and Hemoglobin electrophoresis by High Performance Liquid chromatography (HPLC) in patient group.
The results of this study can be summarized as follow:
There was no significant differences between cases compared to controls as regards age and sex (p>0.05).
There was significant differences between cases compared to controls as regards family history which was 70% in patients (p<0.05).
In beta-thalassemia major patients, Hb, RBCs, MCV, MCH were significantly lower, while platelets counts were significantly higher than the control subjects (p<0.05).
The mean serum ferritin level was significantly higher in thalassemia group than control group (p<0.05).
There was significant decrease in total antioxidant capacity in beta-thalassemia major patients as compared with the healthy controls (p value< 0.05).
The results of MTHFR genotyping showed that homozygous mutant genotype TT and heterozygous CT was significantly higher in patients with beta thalassemia major than in controls (p< 0.05).
The T allele frequency is significantly higher in beta thalassemia group than in controls (p< 0.05).
In this study total antioxidant capacity was significantly lower in TT group than both of CC and CT groups (p< 0.05).