In comparison to pathogenic gene variants in nuclear or mtDNA, children with Leigh syndrome as a result of pathogenic recessive variants in the SURF1 gene were significantly associated with poorer survival (χ2[2] = 41.8, p < 0.001; see Fig 5C) and were associated with a 3.1‐fold increased risk of death (risk ratio = 3.1, 95% CI = 1.0–10.1). This evidence concerns the gene SURF1 and Leigh syndrome.