We addressed this question in the largest cohort analyzed to date, including 29,612 ALS/MND patients and 122,656 controls, and found that MND patients were significantly enriched with the APOE ε3/ε3 haplotype but depleted of the ε2/ε2 and the ε4/ε4 haplotypes. Here, APOE is linked to mild neurocognitive disorder.