Cellosaurus Disease Terminology mCode Terminology mCode Elixhauser Dementia Value Set Rare Non-Neoplastic Disorder Leigh Disease Disease or Syndrome Cellosaurus Leigh's Disease NICHD mCode Leigh Disease Leigh's disease Leigh Syndrome Leigh Disease C4229116 C84814 An inherited disorder affecting the nervous system, caused by genetic mutations in the mitochondrial DNA or deficiency of pyruvate dehydrogenase. Signs and symptoms appear in infancy and include loss of the motor abilities, poor sucking abilities, irritability, lack of muscle tone, and seizures. NICHD Terminology Neonatal Research Network Terminology