A rare inborn error of metabolism disorder with early-onset acute encephalopathic episodes (frequently triggered by viral infections) associated with lactic acidosis and alpha-ketoglutaric aciduria which typically manifest with variable degrees of ataxia, generalised developmental regression (which deteriorates with each episode) and dystonia. Other manifestations include spasticity, seizures, truncal hypotonia, limb hypertonia, brisk tendon reflexes and reversible coma. Caused by homozygous or compound heterozygous mutation in the TPK1 gene on chromosome 7q35.

A rare inborn error of metabolism disorder with early-onset acute encephalopathic episodes (frequently triggered by viral infections) associated with lactic acidosis and alpha-ketoglutaric aciduria which typically manifest with variable degrees of ataxia, generalized developmental regression (which deteriorates with each episode) and dystonia. Other manifestations include spasticity, seizures, truncal hypotonia, limb hypertonia, brisk tendon reflexes and reversible coma. Caused by homozygous or compound heterozygous mutation in the TPK1 gene on chromosome 7q35.