Molecular genetic study of B-thalassemia major syndrome in Baghdad.+CD

number: 
1932
English
Degree: 
Imprint: 
Biotechnology
Author: 
Ro'ya Hadi Kazal Al-Hadad
Supervisor: 
Dr. Mohammed A. Ibrahim
Dr.Abdul Basit N. Jassim
year: 
2007
Abstract:

In this work, seventy of ?-thalassemia patients were subjected to pedigree analysis, hematological analysis of peripheral blood smears, hemoglobin electrophoresis and molecular analysis of ?-globin gene in comparison with normal people. The conventional hematological procedures were made for patients with ?-thalassemia major who were attending Central Public Health Lab/Ministry of Health from different regions of Baghdad, the hematological tests were PCV, MCV, MCH and the results showed that PCV percentages were in the range 18-27% for patients and 36-43% for carriers (parents) while for normal 37-54%, MCH values were 20.7-26 pg for patients and 16.6-19.1 pg for carriers and for normal 27-31 pg, MCV values were 67.2-79.3 fl for patients and 61.5-66.6 fl for carriers in comparison with normal people 80-94 fl. On the other hand, it was found in blood samples which were collected from the patients that there were abnormalities in the morphological appearance of RBCs which showed severe degree of microcytes, hypochromia, anisocytosis and variation in shape which included target cells, tear-drop cells, in comparison for normal people the morphological appearance of RBCs are normochromic and normocytic. HbA2, Hb F, HbA were determined by three electrophoresis techniques which were cellulose acetate electrophoresis, agarose gel electrophoresis and hemoglobin testing system (variant), the result showed that most of the patients with ?-thalassemia syndrome had low level of HbA due to the absence of either one or both of ?-globin gene, whereas, most of the patients carrier had a high ratio of HbF and HbA2 comparison with normal people. The results of pedigree analysis of ?-thalassemia for four families showed that the syndrome is transmitted as an autosomal recessive pattern, which suggest that the condition generate from the intermarriage between relatives. The molecular analysis of genomic DNA for Iraqi families with ?-thalassemia by using specific primer for PCR amplification and Restriction analysis with Bsu361. The result showed the presence of point mutation (Frameshift 6 mutation) in ?-globin gene in ?-thalassemia major which cause a complete depression in the expression of ?-globin genes. Fragment sizes obtained from PCR amplification were 616 bp and the presence of fragment (616 bp) from Restriction analysis. The results were good indication for the type of mutation causing ?-thalassemia, thus it was possible to conclude that point mutation is causing inactivation of ?-globin gene.