has material basis in germline mutation in SDHC mitochondrial respiratory chain complex deficiency SDHC-related Mitochondrial Disease https://github.com/monarch-initiative/mondo/issues/9178 GARD:0028021 SDHC-related Mitochondrial Disease MONDO:0700347 Mitochondrial complex II deficiency due to pathogenic variants in the SDHC gene, resulting in a variety of clinical manifestations, including neurological and muscular symptoms.