Idiopathic Hyperglycinemia and Hyperglycinuria: A New Disorder of Amino Acid Metabolism. I

Observations are reported of a patient afflicted with a disease previously unknown to us. The outstanding features of the syndrome are: onset in the neonatal period of episodes of vomiting, lethargy and ketosis; neutropenia; periodic thrombocytopenia; hypogammaglobulinemia; hyperglycinemia and hyperglycinuria; developmental retardation; and intolerance of protein of more than approximately 0.5 gm/kg of body weight/day and of protein hydrolysate and of leucine.