Pediatric Mitochondrial Disease: Clinical and Genetic Insights From a Single-Center Cohort

Background: Mitochondrial diseases are a heterogeneous group of inherited metabolic disorders characterized by dysfunction in oxidative phosphorylation, leading to impaired cellular energy metabolism. These disorders present with a broad clinical spectrum, often involving the nervous system, muscles, heart, and liver, making diagnosis complex. Methods: This retrospective study evaluates the clinical, laboratory, and genetic characteristics of 19 pediatric patients diagnosed with mitochondrial diseases at the pediatric metabolism clinic. Results: The most common clinical findings were hypotonia (52.6%), lactic acidosis (26.3%), and seizures (21.1%), followed by neuromotor delay (10.5%) and bilateral optic atrophy (10.5%). These findings reflect the multisystemic involvement and neurological predominance typical of mitochondrial disorders. Biochemical analyses frequently revealed abnormal metabolic profiles supportive of mitochondrial dysfunction. Conclusions: Genetic analyses identified various mitochondrial DNA and nuclear DNA mutations, underscoring the importance of comprehensive molecular diagnostics. Molecular testing improved diagnostic accuracy and facilitated more tailored patient management, including early initiation of supportive treatments and genetic counselling.