GSTM1 and thalassemia: For example, HbS is prevalent in Africa and India, thalassemias are common in the Mediterranean, Middle East, and Southeast Asia, HbC is common in West Africa, HbD-Punjab has been found in the Indian subcontinent, HbE is highly prevalent in Southeast Asia, Hb Lepore is prevalent in Southern Italy and Mediterranean populations, Hb Constant Spring (Hb CS) is common in Southeast Asia, Hb Bart’s (γ4) has been found in individuals with α-thalassemia, prevalent in Saudi Arabia and Thailand.