How common is thalassemia?

Millions of carriers: 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.

Depends : Worldwide incidence: 30 out of 1000 people the highest incidence is: 150-300 out of 1000 in italy, greece, and among americans of italian or greek descent. https://www.clinicalkey.com/topics/hematology/thalassemia.html.