Of the patients with haemoglobinuria, 3.0% (1/33) had reduced CYP2D6 activity, and 5.0% (1/20) had G6PD deficiency, and the difference in the prevalence between CYP2D6 (x2 = 1.29, p = 0.257) or G6PD (x2 = 0.10, p = 0.751) status was not statistically significant. Here, CYP2D6 is linked to G6PD deficiency.