Neonatal type of nonketotic hyperglycinemia.

Two infants with the neonatal type of nonketotic hyperglycinemia that had manifested as early neonatal consciousness disturbance are presented. Transient hyperammonemia had been detected in both initially. High levels of glycine in plasma and cerebrospinal fluid disturb the nervous system, causing variable manifestations of this disease. Both cases were complicated by intracranial hemorrhage, which has never before been reported. After treatment with sodium benzoate and dextromethorphan, some neurologic improvement was observed, although the glycine levels did not lower. Recent clinical trials are reviewed, and because of the unfavorable outcomes, the special need for prenatal diagnosis is highlighted.