The Urea Cycle Disorders section contains posts that cover the biochemistry, pathology, and molecular biology of the disorders that result due to mutations in genes encoding the enzymes of the urea cycle.
Last Updated: August 3 2026 Introduction to NAGS Deficiency N-acetylglutamate synthase deficiency (NAGSD) is most commonly the result of the inheritance of pathogenic variants in the NAGS gene which encodes N-acetylglutamate synthase. NAGSD manifests in two forms...
Last Updated: July 13, 2026 Introduction to Arginase Deficiency Arginase deficiency (AD) represents one of the disorders that result from defects in the processes of the urea cycle. Arginase deficiency is a rare autosomal recessive disorder. Arginase deficiency is the...
Last Updated: July 13, 2026 Introduction to Argininosuccinate Lyase Deficiency As the name implies, argininosuccinate lyase deficiency (ALD) is a disorder resulting from pathogenic variants in the gene (ASL) encoding the urea cycle enzyme, argininosuccinate lyase....
Last Updated: July 13, 2026 Introduction to Argininosuccinate Synthetase Deficiency Arginosuccinate synthetase (also identified as argininosuccinate synthase) deficiency (ASD) is an autosomal recessive disorder of the urea cycle that also affects the synthesis of...
Last Updated: July 13, 2026 Introduction to OTC Deficiency Deficiencies in each of the enzymes of the urea cycle have been identified. Collectively, these enzyme deficiencies lead to a family of disorders referred to as the urea cycle disorders (UCD). The most...
Last Updated: July 13, 2026 Introduction to CPS1 Deficiency Carbamoyl phosphate synthetase 1 deficiency (CPSD) is an autosomal recessive disorder that, as the name implies, is due to pathogenic variants in the gene (CPS1) encoding the urea cycle enzyme, carbamoyl...
Last Updated: July 13, 2026 Introduction to the Urea Cycle Disorders (UCD) A complete lack of any one of the enzymes of the urea cycle is associated with an significant increase in the likelihood for death shortly after birth. Nonetheless, deficiencies in each of the...