hyperammonemia

hyperammonemia

 [hi″per-am″mo-ne´me-ah]

elevated levels of ammonia or its compounds in the blood. A congenital form occurs in two types: Type 1, due to deficiency of the enzyme ornithine carbamoyltransferase, is marked by vomiting, lethargy, coma, and hepatomegaly; symptoms are aggravated by protein ingestion. Type 2, due to deficiency of the enzyme carbamoyl phosphate synthetase (ammonia), is marked by vomiting, lethargy, and flaccidity and by elevated plasma and urinary levels of glycine. Hyperammonemia may also occur in nongenetic diseases such as severe liver disease.

Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.

am·mo·ne·mi·a

, ammoniemia (am'ō-nē'mē-ă, am'ō-ne-ē'mē-ă),

The presence of ammonia or some of its compounds in the blood, thought to be formed from the decomposition of urea; it usually results in subnormal temperature, weak pulse, gastroenteric symptoms, and coma.

Synonym(s): hyperammonemia

[ammonia + G. haima, blood]

Farlex Partner Medical Dictionary © Farlex 2012

hyperammonemia

Metabolism A heterogeneous group of five largely AR inborn errors of metabolism; each has a defect in a urea cycle enzyme–arginase, argininosuccinase, argininosuccinic acid synthetase, carbamyl phosphate synthetase, ornithine transcarbamylase; all begin in late infancy or childhood, except arginase deficiency, which is neonatal Clinical Accumulation of urea precursors–eg, ammonia, glutamine causes progressive lethargy, hyperthermia, apnea, hyperammonemia Diagnosis may be established in utero by restriction fragment–RFLP analysis Treatment Restrict dietary protein; activate alternate pathways of waste nitrogen excretion–eg, sodium benzoate or dietary supplementation with arginine

McGraw-Hill Concise Dictionary of Modern Medicine. © 2002 by The McGraw-Hill Companies, Inc.