Of these 22 pairs, 20 (90.9%) had a significant (IVW P < 0.05) association to the same trait as predicted by single-cell MR, including GPNMB-PD (IVWbrain protein—P = 2.48 × 10−8, β = 0.39), SCFD1-amyotrophic lateral sclerosis (IVWbrain protein—P = 1.14 × 10−13, β = 1.61) and ICA1L-WMH (IVWbrain protein—P = 2.51 × 10−13, β = 1.27; Fig. 5e, Supplementary Table 11 and Supplementary Fig. 16). The gene discussed is ICA1L; the disease is amyotrophic lateral sclerosis.