The genotype and phenotype correlation between coinheritance of heterozygous
beta-thalassemia with the
alpha-globin triplication is unclear. In this study we have investigated and reviewed alpha triplication frequency in
beta-thalassemia carriers,
sickle cell trait, and healthy individuals and its effect on hematological and phenotypical changes. In this study, 4005
beta-thalassemia carriers, 455
sickle cell trait, and 2000 healthy individuals were included. Molecular characterization of beta and
alpha-thalassemia was performed. The frequencies of
alpha-globin triplication in
beta-thalassemia carriers,
sickle cell trait, and healthy individuals were 67 (1.67%), 4 (0.88%), and 18 (0.9%), respectively. In total, the frequency of alpha-triplications is approximately 89 (1.39%) in Khuzestan province, South of Iran population. We have compared the average hematological parameters of
beta-thalassemia carriers,
sickle cell trait, and healthy individuals with and without alpha gene triplication. This mutation did not show any significant effect on the change of blood indices, neither in healthy individuals nor in
sickle cell trait and
beta-thalassemia carriers. Therefore, there is no need to take more notice of anti 3.7 mutation in
beta-thalassemia carriers is opposed with some studies reported that the presence of excess
alpha-globin genes in
beta-thalassemia carriers can lead to the phenotype of
beta-thalassemia intermedia. Therefore, not every individual with triplicated
alpha globin coinherited with
beta-thalassemia trait will have a significantly lower Hb than normal, and it is highly likely that none of them will need transfusion.