biostudies-literatureKistol DMinistry of Science and Higher Education of the Russian FederationRussian Science Foundation1597https://www.ebi.ac.uk/biostudies/studies/S-EPMC9865855biostudies-literatureUnknown24(2)Leigh syndrome (LS), also known as infantile subacute necrotizing encephalopathy, is the most frequent mitochondrial disorder in children. Recently, more than 80 genes have been associated with LS, which greatly complicates the diagnosis. In this article, we present clinical and molecular findings of 219 patients with LS and give the detailed description of three cases with rare findings in nuclear genes <i>MORC2, NARS2</i> and <i>VPS13D</i>, demonstrating wide genetic heterogeneity of this mitochondrial disease. The most common cause of LS in Russian patients are pathogenic variants in the <i>SURF1</i> gene (44.3% of patients). The most frequent pathogenic variant is c.845_846delCT (66.0% of mutant alleles; 128/192), which is also widespread in Eastern Europe. Five main LS genes, <i>SURF1International journal of molecular sciencesLeigh Syndrome: Spectrum of Molecular Defects and Clinical Features in Russia.PMC98658550517-2019-000823-45-10010Migiaev OSumina MItkis YZakharova EPechatnikova NBychkov ITsygankova PKrylova TKurbatov SMikhailova SNikolaeva EKistol DBostanova FfalseLeigh Syndrome: Spectrum of Molecular Defects and Clinical Features in Russia.Leigh syndrome (LS), also known as infantile subacute necrotizing encephalopathy, is the most frequent mitochondrial disorder in children. Recently, more than 80 genes have been associated with LS, which greatly complicates the diagnosis. In this article, we present clinical and molecular findings of 219 patients with LS and give the detailed description of three cases with rare findings in nuclear genes <i>MORC2, NARS2</i> and <i>VPS13D</i>, demonstrating wide genetic heterogeneity of this mitochondrial disease. The most common cause of LS in Russian patients are pathogenic variants in the <i>SURF1</i> gene (44.3% of patients). The most frequent pathogenic variant is c.845_846delCT (66.0% of mutant alleles; 128/192), which is also widespread in Eastern Europe. Five main LS genes, <i>SURF12023-01-01T00:00:00Z2023 Jan2025-04-04T10:19:39.213Z2025-02-19T00:12:37.087ZS-EPMC98658553667512110.3390/ijms24021597