Evaluation of Α-Globin Gene Mutations Among Different Ethnic Groups in Khuzestan Province, Southwest Iran Publisher Pubmed



Khosravi A¹ ; Jalalifar M² ; Saki N² ; Hosseini H² ; Galehdari H² ; Kianighalesardi O² ; Paridar M³ ; Azarkeivan A⁴ ; Magajihamid K^{5, 6} Show Affiliations
Source: Hemoglobin Published:2016

Abstract

α-Thalassemia (α-thal) is one of the most common inherited hemoglobin (Hb) disorders in the world. In addition to large deletions, over 50 different α-thal point mutations were detected around the world, thus, patients showed different phenotypes with regard to genotype. This study evaluated the genetic frequency of α-thal in Khuzestan Province, Southwest Iran, to help implement premarital and prenatal screening programs. The study was conducted on couples proposing to get married and parents who were referred to the genetic center of Shafa Hospital, Ahvaz, Iran, for prenatal diagnosis (PND) in 2012. Genomic DNA was purified by the salting-out method and tested using multiplex gap-polymerase chain reaction (gap-PCR), amplification refractory mutation system-PCR (ARMS-PCR), reverse hybridization test strips and DNA sequencing. Overall, 11 mutations were found on the α-globin genes. Based on gene frequency, the most common mutant allele was -α3.7 (rightward) (71.3%) followed by the two gene deletion - -MED (9.7%). Other common mutations were αcodon 19α (GCG>GC-, α2) (8.4%), the polyadenylation (polyA1) site αpolyA1α (AATAAA>AATAAG) (2.8%), and α-5 ntα (-TGAGG) (2.0%). In addition, an extremely rare mutation at αcodon 21α [Hb Fontainebleau, HBA2: c.64G > C (or HBA1)] was also found. The results of this study are critical for correct diagnosis of α-thal carriers, premarriage counseling and PND. This study suggests that the distribution of mutations on the α-globin genes differs among the ethnic groups in Khuzestan Province as well as in other provinces. © 2016 Taylor & Francis.