The Spectrum of α-Thalassemia Mutations in Kermanshah Province, West Iran

Thalassemia is a hereditary blood disorder that results from genetic defects causing deficient synthesis of hemoglobin (Hb) polypeptide chains. Although thalassemia mostly affects developing countries, there is limited knowledge of its accurate frequency and distribution in these regions. Knowing the prevalence of thalassemia and the frequency of responsible mutations is therefore an important step in the prevention and control program as well as treatment strategies. alpha-Thalassemia (alpha-thal) is prevalent in Middle East Asian populations, including Iran. In this study, 678 unrelated alpha-thal carriers, attending the Kermanshah Medical Genetics Laboratory, Kermanshah, Iran, were investigated for alpha-globin gene mutations by multiplex polymerase chain reaction (PCR) and direct sequencing. The most common mutation among our patients was -alpha(3.7) (rightward) (60.9%) deletion, which is also known to occur in high frequencies in other parts of Iran, in Southeast Asia and Mediterranean countries. Other prevalent alpha-thal mutations were alpha(-5) (nt) (10.6%), alpha(polyA4) (9.9%), alpha(polyA6) (3.7%), - -(MED) (3.2%), -alpha(4.2) (leftward) (3.1%) deletion and codon 59 (Hb Adana; HBA1: c.179 G>A) (2.5%). These comprehensive new data are useful for establishing a screening strategy for the effective control of alpha-thal in Kermanshah Province.