In particular, two African ancestry-specific variants, <i>HBB-</i>rs334 and <i>G6PD</i>-rs1050828, which are causal mutations for sickle cell disease and <i>G6PD</i> deficiency, respectively, had ∼10 times larger effect sizes on HbA<sub>1c</sub> levels (β = -0.31% [-3.4 mmol/mol]) and -0.35% [-3.8 mmol/mol] per minor allele, respectively) compared with other HbA<sub>1c</sub>-associated variants (0.03-0.04% [0.3-0.4 mmol/mol] per allele).