PGAP6 and thalassemia: In the 2SLS IV analysis for the direction and causality of α-thalassemia-related erythrocyte indices and cardiometabolic traits, the association of PGAP6 rs375498857 genotypes with cardiometabolic traits remained significant even after adjustment for multiple parameters associated with MCV or MCH (Table 5): the association between the rs375498857 genotype and LDL cholesterol levels and DM subsided after adjustment for MCH.