The SUCLA2 gene is located on chromosome 13 (13q14.2). Biallelic mutations in this gene cause a deficiency of the enzyme succinyl-CoA synthase in the Krebs cycle. The reaction catalysed by the enzyme also represents a distal step of the methylmalonic acid pathway. The SUCLA2 defect is an inborn error of metabolism (MIM #612073). The defect leads to an early infantile Leigh-like encephalopathy and a mitochondrial depletion syndrome with dystonia and deafness. Patients with the SUCLA2 defect have been reported from various parts of the world. Inheritance is autosomal recessive.