Thalassemia Gene Mutations in Kohgiluyeh and Boyer-Ahmad Province

Thalassemia is the most common hereditary anemia which has a relatively high prevalence in Iran. In most cases, more than 300 mutations have been identified, which affect genes of alpha and beta globin chains and lead to lack of production or reduction of chains. Iran’s population is composed of different ethnic groups, thus, determining the frequency and distribution of these mutations is essential in different parts of the country. We aimed to assess Thalassemia gene mutations in Kohgiluyeh and Boyer-Ahmad province.

In this cross-sectional study, 656 couples were selected and their Genomic DNA was extracted by DNA extraction kit method and tested using multiplex gap-polymerase chain reaction (gap-PCR), amplification refractory mutation system-PCR (ARMS-PCR), and DNA sequencing. Finally all data were analyzed using the SPSS version 17 software.

More than 13 mutations were found on α-globin genes. Based on gene frequency, the most common mutant allele was –α3.7/αα (rightward) (71.3%) followed by the two gene deletion −α3.7/−α3.7 (2.5%). Other common mutations were polyA2 (2.1%), αcodon 19α/αα (1.7%), –α3.7/αα/–α3.7/αα (1.5%), – (α) 20.5 (0.6%), α−5 nt/αα (0.5%), and other mutations. In this study, more than 21 mutations were identified on beta thalassemia gene. The most common mutation was CD36- /37 (-T) (19.8%). Other common reported mutations included IVSII-1 (G>A) (9.5%), IVS I-110 (G>A) (4.7%), IVSII-745 (C>G) (4.4%), codon 82/83(-G) (3.7%), FSC 8/9 (+G) (1.7%), Codon19(1.5%), 25 bp deletion (beta0) (1.5%), IVS-I-116 (T>G) (1.4%), IVSI-6 (G>C) (1.1%), codon 5 (-CT) (0.9%), codon 88 (-C) (0.5%), and IVSI-1(G>A) (0.3%).

The frequencies of these mutations were different in various parts of the country. Therefore, defining thalassemia mutations is necessary to establish prenatal diagnosis programs leading to lower medical cost in Kohgiluyeh and Boyerahmad province.