A total of 23 common variants are included in the test: α‐thalassemia deletions including –SEA (Southeast Asia): −α3.7 and −α4.2: α‐thalassemia point variants including Hb Constant Spring (Hb CS) (HBA2: c.427 T > C), Hb WS (HBA2: c.369C > G) and Hb Quong Sze (Hb QS) (HBA2: c.377 T > C): and 17 β‐thalassemia point variants [21]. Here, GSTM1 is linked to alpha thalassemia spectrum.