Frequency of Beta-globin gene mutations in beta-thalassemia patients from east of Mazandaran

Background and Beta-thalassemia is the most common inherited disorder in the world, especially in Iran. According to Iranian thalassemia society registry, 18616 thalassemia patients now living in Iran, which Mazandaran and Fars provinces have the most patients. Previous reports have shown that the frequency of b-thalassemia carriers is more than 10% in Mazandaran province. Although b-thalassemia is very heterogenous in the molecular level, but in each population, 5 to 10 mutations are more common. In this research common mutation in eastern area of Mazadaran province was investigated. 5 to 10 ml peripheral blood samples were collected from volunteer patients who were referred to Boali Sina Hospital in Sari. DNA was extracted from blood, then 20 different mutations were screened and detected using two different methods, ARMS-PCR and Reverse-Dot Blot in Thalassemia Research Center in Sari and Amir Kola Thalassemia Center. From 240 chromosomes investigated in 120 b-thalassemia patients in total, 96.25% mutations were identified. 13 different mutations were identified from 231 chromosomes. Among different mutations investigated, IVSII-1G>A was detected as the most common with frequency of 68/3%, which was homozygous in 64 individuals (53/3%) and compound heterozygous with other mutations in 34 individuals (28/3%) respectively. Mutations C8(-AA), codon22(G>A)/ FSC 22/23/24(-7bp), codon 30(G>A), and IVSII-1G>A were identified in 83% of chromosomes which were studied (200 chromosomes from 240). Mutation IVSII-1G>A is the most common mutation in northern provinces (Gilan, mazandaran, Golestan) in recent study. Also, comparison of these results with the similar finding from other provinces showed that the distributions of mutations in the northern area are different with northwest, south or southeast of the country.