GDNF (glial cell line-derived neurotrophic factor; Beta = −0.083, 95% CI: −0.134 to −0.031, p=0.002), IL5 (Beta = 0.115, 95% CI: 0.031–0.198, p=0.007), TRAIL (TNF-related apoptosis-inducing ligand; Beta = −0.054, 95% CI: −0.099 to −0.009, p=0.018), and LIFR (Beta = 0.069, 95% CI: 0.002–0.135, p=0.043) were causally associated with LS. The gene discussed is GDNF; the disease is Leigh syndrome.