Abstract

One hundred blood samples of clinically thalassaemic patients were collected from three thalassaemia centers in Iraq, Ibn Al-Baladi hospital, Al- Karama hospital both in Baghdad and Hiwa hospital for cancer diseases and thalassemia unit in Sulaymaniyah. Besides, blood samples were taken from 45 apparently healthy individuals (without Hemoglobinopathy disorders) as a control group. Ethological distribution of the samples revealed that the collected samples from thirteen governorates that represent various parts of Iraq. Blood samples were subjected to DNA isolation and molecular detection of seven types of β-thalassaemia mutations (IVS1 nt.5, codon 8/9, codon 15, codon 8, codon 30, -88, codon41/42) using a PCR -ARMS technique. It was found that two of the diagnosed mutations were reported for the first time within Iraqi population were codon 15 and -88 with the frequency 7 (18.4%) and 4(10.5%), respectively and the most frequent β- thalassaemia mutations were codon 8/9 and IVS1 nt.5 with the frequency 15 (39.5.%) and 10(26.3%), respectively. The study also reveals that codon 30 and codon 41/42 were not found within the studied samples. The geographical distribution of positive diagnosed mutations of thalassaemic patients observe in the map of Iraq, the results revealed the heterogeneity of diagnosed mutations within the Iraqi regions. As can be seen from the distribution of mutations presenting on the Iraqi map, IVS-?-5 and codon 15 were more occurred in the middle and south of Iraq, whereas codon 8/9 and codon 8 mutations were more obvious in the middle and north of Iraq. In addition, -88 mutation was found in the nearby cities of western of Iraq. levels of Serum malondialdehyde (MDA), Iron, ferritin and erythrocyte superoxide dismutase (SOD) and glutathione peroxidase (GPX) activities were significantly increased in β-thalassemia patients compared with healthy controls. A significant decrease in the levels of vitamin E and C, in addition to the values of Total Iron Binding Capacity (T.I.B.C) were not changed in thalassemic patients against healthy control. Ferritin levels showed a significant positive correlation with MDA values (r2 = 0.794), while Serum levels of vitamin E was negatively correlated with ferritin and MDA values (r2 = 0.6815, 0.552, respectively) . The apoptotic response shown by thalassemic cells was evaluated using three methods, (comet assay, DNA fragmentation assay and Annexin V-FITC(Fluorescein isothiocyanate) apoptosis). Comet assay result was demonstrated as comet index which represent a mean of the scored which calculate from the ratio of cell diameters (L/W) of total cells in each sample. These results revealed that lymphocytes cells exhibited an increase apoptosis percentage (48.2%) compare with percentage of control (6.5%). This revealed that there was DNA damage in β-thalassemic patients. The results obtained by DNA fragmentation assay reveal in severe DNA damage of the thalassemic patients according to the molecular weight of the ladder. The smear shape pattern on gel electrophoresis indicating double strand breakage of the DNA was detected of 43.3% in studied thalassemic samples. . Compared to the control and MW of ladder, the thalassemic patients had higher prevalence of DNA double-strand breaks in their leukocytes.The final experiment of apoptosis study involved the utilization of Annexin-V- FITC kit to monitor apoptotic and necrotic induction in thalassemic cells. The results showed high apoptotic percentages in thalassemia's patients (50.89%) for patients who exposed repeated transfusion for long periods and who take irregularly chalation therapy and they have complication due to transfusion compared to healthy people. The percentage of apoptosis for mutations samples in thalassemic patients: 78.9% for comet assay, 76.3% for DNA fragmentation analysis and 86.8% for labeling Annexin V assay.