Prevalence of α-Thalassemia 3.7 and 4.2 kb Deletion in Microcytic Hypochromic Anemia Patients from Gaza Strip –Palestine

Abstract

α-Thalassemia results from impaired α-globin chain synthesis that usually comes about through deletion of α-globin genes. This study was conducted to detect and investigate the prevalence of -α^3.7 and -α^4.2 deletion mutations in a cohort of microcytic hypochromic anemic patients from Gaza Strip-Palestine. 200 unrelated adult patients, 18 to 48 years old, were recruited from the Hematological departments of the three major Gaza strip hospitals (Al-Shifa, Gaza-European and Nasser). The study participants proved negative upon β-thalassemia carrier screening. Serum iron and total iron binding capacity (TIBC) were tested to exclude iron deficiency. Multiplex-PCR was used for the molecular detection of -α^3.7 and -α^4.2 deletion mutations. Thirty-one (15.5%) of the investigated cases have α-thalassemia, of which 27 (13.5%) harbored a heterozygous genotype (-α^3.7/αα) and three (1.5%) wee homozygotes (-α^3.7/-α^3.7). -α^4.2 deletion was evident in one (0.5%) case only and in a heterozygous state. The frequency of -α^3.7 and-α^4.2 alleles were 8.25% and 0.25% respectively. Comparison of hematological parameters between microcytic hypochromic patients with normal genotype and those harboring mutations showed that the -α^3.7/-α^3.7 subjects have lower Hb level and statistically significant difference in the MCV (p =0.006) and MCH (p =0.007). Further studies should be done on normocytic normochromic individuals, since α-thalassemia silent and trait cases may have normal red blood cells indices.