Other patients with neonatal-onset epilepsy, encephalomyopathy, muscular hypotonia, lactic acidosis, and defects in pyruvate and glycine metabolism were also reported to have genetic mutations in LIAS. These severe symptoms were linked to a homozygous single-nucleotide polymorphism c.746 G > A in the LIAS gene, resulting in the replacement of Arg249 with His45. The gene discussed is LIAS; the disease is mitochondrial DNA depletion syndrome, encephalomyopathic form with methylmalonic aciduria.