Abstract Dibasicaminoaciduria with hyperammonemia was observed in a mentally and physically retarded patient. Oral loading test results revealed diminished capacity to absorb lysine compared to five normal controls and served to distinguish this patient from those with familial protein intolerance. Fasting plasma arginine and lysine concentrations were decreased to 10% to 50% of normal values, presumably because of decreased intestinal absorption and increased renal excretion. The severe postprandial hyperammonemia may be due to a lack of substrate (arginine) for urea cycle activity. Arginine and lysine deficiency may impair protein synthesis and this factor may be involved in the observed physical and mental retardation. The patient is an example of a previously unrecognized syndrome characterized by dibasicaminoaciduria with defective intestinal absorption of lysine, severe postprandial hyperammonemia with seizures, mental retardation, and subnormal growth and physical development. References 1. Kekomaki M, Visakorpi JK, Perheentupa J, et al: Familial protein intolerance with deficient transport of basic amino acids . Acta Paediat Scand 56:617-630, 1967.Crossref 2. Oyanagi K, Miura R, Yamanouchi T: Congenital lysinuria: A new inherited transport disorder of dibasic amino acids . J Pediat 77:259-266, 1970.Crossref 3. Whelan DT, Scriver CR: Hyperdibasicaminoaciduria: An inherited disorder of amino acid transport . Pediat Res 2:525-534, 1968.Crossref 4. Kekomaki M: Intestinal absorption of l-arginine and l-lysine in familial protein intolerance . Ann Paediat Fenn 14:18-22, 1968. 5. Pellizzari ED, Brown JH, Talbot P, et al: An evaluation of the gas chromatographic analysis of plasma amino acids . J Chromatogr 55:281-289, 1971.Crossref 6. Lamkin WM, Gehrke CW: Quantitative gas chromatography of amino acids: Preparation of n-butyl n-trifluoroacetyl esters . Anal Chem 37:383-389, 1965.Crossref 7. Rosenberg LE, Scriver CR: Disorders of amino acid metabolism , in Bondy PK (ed): Duncan's Diseases of Metabolism , ed 6. Philadelphia, WB Saunders Co, 1969, vol 1. 8. Hopkins IJ, Connelly JF, Dawson AG, et al: Hyperammonaemia due to ornithine transcarbamylase deficiency . Arch Dis Child 44:143-148, 1969.Crossref 9. Cabello J, Basilio C, Prajoux V: Kinetic properties of erythrocyte and liver arginase . Biochim Biophys Acta 48:148-152, 1961.Crossref 10. Archibald RM: Colorimetric determination of urea J Biol Chem 157:507-518, 1945. 11. Reichard H: Determination of ornithine carbamoyl transferase in serum . J Lab Clin Med 63:1061-1064, 1964. 12. Freeman JM, Nicholson JF, Masland WS, et al: Ammonia intoxication due to a congenital defect in urea synthesis . J Pediat 65:1039-1040, 1964.Crossref 13. Kirkman HN, Kiesel JL: Congenital hyperammonemia , Pediat Res 3:358-359, 1969. 14. Sherlock S: Diseases of the Liver , ed 4. Philadelphia, FA Davis Co, 1968, p 40.
American Journal of Diseases of Children – American Medical Association
Published: Jul 1, 1972