Three instances of neonatal death with hyperammonaemia, each resulting from a different cause.

We report here the results of a study of three unrelated patients, K., M. and R., each of whom died in the neonatal period in St Sophia's Children's Hospital, Athens, Greece, after a normal pregnancy and delivery. Liver functions tests and blood cultures gave normal results in each case and autopsy did not reveal any specific findings. All had gross hyperammonaemia and were considered to have possible urea cycle defects.