Study of type and frequency of Alfa-thalassemia mutations in a cohort of 3,823 patients from Isfahan Province, Iran

Introduction: Alpha-thalassemia (α-thalassemia) is caused by a range of mutations in the α-globin gene resulting in the complete reduction or absence of α-globin chain production. Material and methods: This study assessed the presence of α-thalassemia in 3,823 patients referred to Al-Zahra Hospital, Isfahan, Iran during a 10-year period (from 2012 to 2022). These patients experienced anaemia for more than ten years but had not the full indication for β-thalassemia or iron deficiency. Results: Based on the present assessment, 3,483 cases out of 3,823 suspicious cases had an α-Thalassemia-involved mutation (91.1%). According to the results, the most common detected mutation in the α-thalassemia carriers of Isfahan province was –α 3.7 with a frequency of 81.58% (3,119 individuals), followed by α 5nt (–TGAGG) (3.71% in total or 39.01% between 364 patients), polyadenylation signal mutations (polyA2) (14.28% between 364 patients), α codon 19 (GCG4GC–, a2) (11.53%), –α 3.7 /–α 3.7 (11.53%), –α 20.5 (7.69%), Hb Constant Spring [Hb CS, a142, Stop →Gln; HBA2: c.427T4C] (5.7%), α 4.2 (5.49) and – – MED (4.67%). Conclusion: The results of this investigation may be valuable for designing a program for carrier screening, premarital genetic counselling, and prenatal diagnosis in the Isfahan province.