It typically presents as a severe encephalopathy with myoclonic seizures, is rapidly progressive and eventually results in respiratory arrest. Standard evaluation for inborn errors of metabolism and other causes of this presentation does not reveal any abnormality (no acidosis, no hypoglycaemia, or hyperammonaemia and no other organ affected). Pronounced and sustained hiccups in an encephalopathic infant have been described as a typical observation in non-ketotic hyperglycinaemia.
Glycine encephalopathy
Toxic encephalopathy
Ethylmalonic encephalopathy
Wernicke encephalopathy
Post-encephalitic parkinsonism
Early myoclonic encephalopathy
Carbamate poisoning
Viral encephalitis