Family history. Thalassemia is a genetic disease of the hemoglobin molecule and so only occurs through inheritance. A mutation in this gene is especially prevalent in persons of african, asian, middle eastern or mediterranean descent. Individuals with only one mutation of the gene will be asymptomatic, so genetic screening is necessary to precisely determine risk.
High risk ethnicity. Thalassemia is one of the most common gene mutations in the world. Overall, an estimated 20-25 million people are carriers (1/300) (about 1/1000 in low-risk peoples, and about 1/30 in high-risk peoples). Low risk: japanese, korean, n. European caucasians, native canadians, native americans. High risk: mediterranean, middle eastern, south asian, south-east asian (western pacific rim), caribbean.