MYORG and mitochondrial disease: Of the 24 index patients, 8 had monogenic IBGC (variants in SLC20A2 in 5 cases, MYORG in 1 case, PDGFB in 2 cases), 4 had a mitochondrial disease phenotype and MT-TL1 m.3243A > C variants, and 2 had monogenic stroke conditions related to MAP3K6 and GAL. Three of the detected variants were novel (Table 1).