co-inheritance of sickle cell trait and thalassemia mutations in south central iran

background: we aimed to determine the incidence of co-inheritance as well as interaction of sickle cell trait (sct) and α thal /β thal mutations in south and south central of iran. method: we employed a pcr and restriction fragment length polymorphism techniques to confirm diagnosis of sickle cell trait. all subjects were screened for any α/β -thalassemia mutations using a gap-polymerase chain reaction and amplification refractory mutations system. results: our results showed combination of sickle cell trait and β-globin mutation results in a severe clinical course of similar to sickle cell disease, while coinheritance of α-globin gene defects usually modulates the clinical course. a coexistence of sickle cell trait and α-globin gene mutation was the frequent genotype in overall samples (57. 5%). conclusion: sickle cell trait mainly co-inherits with α-globin gene mutation in the south and south central region of iran. this combination modulates hematological indices and interferes with the sct diagnosis.