SDHA protein, encoded by the SDHA gene, is a crucial component of the succinate dehydrogenase complex, which is involved in the mitochondrial respiratory chain and the citric acid cycle. This protein acts as a catalytic subunit, facilitating the conversion of succinate to fumarate and transferring electrons to the oxidative phosphorylation pathway. It contains a covalently attached flavin adenine dinucleotide (FAD) cofactor, which is essential for its enzymatic activity. Mutations in the SDHA gene can lead to various disorders, including mitochondrial complex II deficiency, Leigh syndrome, and paraganglioma-pheochromocytoma syndrome. These mutations may result in impaired mitochondrial function, reduced ATP production, and the accumulation of succinate, which can disrupt cellular metabolism and contribute to disease development.