ABSTRACT
We aimed to determine the incidence of co-inheritance as well as interaction of sickle cell trait [SCT] and alpha [that]/beta[that] mutations in south and south central of Iran. We employed a PCR and restriction fragment length polymorphism techniques to confirm diagnosis of sickle cell trait. All subjects were screened for any alpha/beta-thalassemia mutations using a gappolymerase chain reaction and amplification refractory mutations system. Our results showed combination of sickle cell trait and beta-globin mutation results in a severe clinical course of similar to sickle cell disease, while coinheritance of beta-globin gene defects usually modulates the clinical course. A coexistence of sickle cell trait and beta-globin gene mutation was the frequent genotype in overall samples [57. 5%].Sickle cell trait mainly co-inherits with alpha-globin gene mutation in the south and south central region of Iran. This combination modulates hematological indices and interferes with the SCT diagnosis