Prevalence and genetic analysis of α- And β-thalassemia and sickle cell anemia in southwest Iran

Abstract

This prospective study assessed the prevalence and genetic analysis of a- and b-thalassemia and sickle cell anemia (SCA) in Southwest Iran. Hematological indices were measured in 17,581 couples living in Khuzestan Province, Southwest Iran. Individuals with mean corpuscular volume <80, mean corpuscular hemoglobin <27, hemoglobin A2 ≥3/5 were considered as b-thalassemia traits. Prevalence of minor b-thalassemia, a-thalassemia, SCA, iron deficiency anemia, and silent thalassemia were respectively identified in 995 (5.6%), 1169 (6.65%), 1240 (7.05%), 911 (5.18%), and 1134 (6.45%) individuals using a multiplex amplification refractory mutation system, and direct DNA sequencing of globin genes. Three codons IVS-II-1 (G ® A; 26%; n = 13), IVS-I-1 (G ® T; 16%; n = 8), and IVS-I-110 (G ® A; 14%; n = 7) were the most frequent mutants and IVS-II-1 was the most common b-thalassemia mutation. Also, based on a gap-polymerase chain reaction assay, genotype frequencies of a-globin mutations were −a3.7 kb (50%; n = 25), Med/aathal (12%; n = 6), and −a4.2/aa (10%; n = 5), which were the most frequent deletion mutants (72% in total). The most common deletion (50%) was −a3.7 kb. Our data suggest that the population of Southwest Iran is at high risk of a- and b-thalassemia caused by these deletion mutants and SCA. Our findings will be useful for developing an efficient control program and genetic counseling.