Relationship between Bipolar I disorder and β thalassemia minor

Background and Previous studies indicate an important genetic factor in the etiology of β-Thalassemia and bipolar mood disorder. There has been several case reports implicating a possible association between the two conditions. But the results of a cross sectional study was not reconfirming. Regarding different patterns of mutations in different geographical areas, this study was performed to evaluate the genetic association between these two conditions in Mazandaran province in which β–Thalassemia is prevalent. This case-control study was conducted on 110 patients with bipolar I disorder and 118 persons without any history of mood disorders in them and their family. Hemoglobin electrophoresis was performed in all cases and controls that showed microcytosis in their CBC. Hemoglobin A2 between 3.4 to 7 was considered for diagnosis of β-Thalassemia minor. 8.18% of cases and 4.24% of controls were diagnosed to be heterzygote for β-Thalassemia, the difference was not statistically significant. The reported genetic relationship between Bipolar disorders and heterozygous β-Thalassemia probably has been a “false association”. However, as there are different mutations for minor thalassemia in different populations, the authors are aware of low external validity of this study, and suggest farther studies on different populations.