Rare and unexpected beta thalassemic mutations in Qazvin province of Iran

About 13 beta-globin mutations encompass 70 - 90% of mutation spectrum in Iran. These mutations are called common beta-globin mutations. The rest are rare or unknown mutations. The objective of this study was to identify and describe rare or unknown beta-globin mutations in Qazvin province. EDTA-containing venous blood samples were collected from 100 patients with transfusion-dependent beta-thalassemia from the department of pediatrics of Qods hospital of Qazvin. Screening for causal mutations was carried out on DNA isolated from WBC's of the patients by using Amplification Refractory System (ARMS) technique. 14.1% of alleles which were not discovered by ARMS, were uncovered by direct sequencing that include 9 different rare mutations. Thirty-seven combinations of alleles (genotypes) were recognized in all affected patients. The frequency of mutations of nt-30, IVS I-6, Cd5, IVS II-745, 5' UTR, Cd15, Cd39, IVS I-130, Cd24, Cd74/75, HbS and Hb Monroe were about 1% or less. We have revealed and described the existence of 9 rare mutations from Qazvin, two of which (Cd74/75 and Hb Monroe) are the first reported in Iran.