Alpha-globin gene mutation spectrum in patients with microcytic hypochromic anemia from Mazandaran Province, Iran

Abstract

Background: It is estimated about 7 of the world population is carriers of hemoglobin diseases. Alpha-thalassemia is one of the most common hereditary hemoglobin disorders in the world. This study investigated alpha-globin mutations in potential carriers with hypochromic and microcytic anemia from Mazandaran, in northern Iran. Methods: A total of 859 subjects were selected; genomic DNA was extracted and examined for the presence of mutations in the alpha-globin genes. Results: Mutation analysis of alpha-globin genes revealed 27 different mutations. Seven variants were seen in 91.45 of all alpha-1 and alpha-2 mutations among patients in this study. The 3.7 kb deletion is the most frequent mutation with a frequency of 49.53, followed by PolyA2 (15.19), â��4.2 deletion (8.76), —MED (5.84), IVSI-5nt deletion (5.49), Hb constant spring (3.62), and Cd 19 (â��G; 3.04), respectively. There are also seven new variants which were reported for the first time either in alpha-1 or alpha-2 genes, including codon 9 (C > A; α2), deletion of codon 60 (AAG deletion; α2), duplication of codon 94-100 plus 3 base pairs of intron 2 (IVSII + 3; α1), codon 99 (C > A; α2), codon 108 (A > G; α2), codon 128 (A > T; α2), and codon 129 (T > G; α2), respectively. The MLPA method also revealed three rare and novel deletions in alpha-cluster region with about 30 kilobases long. Conclusion: This study showed an efficient identification of α-thalassemia can be achieved using standard hematological indices in our population. The details of these variations will help local genetic services for diagnostic and prenatal diagnosis services. © 2019 The Authors. Journal of Clinical Laboratory Analysis published by Wiley Periodicals, Inc