Trial Parameters
Brief Summary
Urea cycle disorders (UCD) are a group of rare inherited metabolism disorders. Infants and children with UCD commonly experience episodes of vomiting, lethargy, and coma. The purpose of this study is to perform a long-term analysis of a large group of individuals with various UCDs. The study will focus on the natural history, disease progression, treatment, and outcome of individuals with UCD.
Eligibility Criteria
Inclusion Criteria: * Diagnosis of NAGS deficiency, defined as the detection of a pathogenic mutation, and/or decreased (less than 20 % of control) NAGS enzyme activity in liver ,and/or hyperammonemia and first degree relative meets at least one of the criteria for NAGS deficiency * Diagnosis of CPS I deficiency, defined as decreased (less than 20 % of control) CPS I enzyme activity in liver, and/or an identified pathogenic mutation, and/or hyperammonemia and first degree relative meets at least one of the criteria for CPS I deficiency * Diagnosis of OTC deficiency, defined as the identification of a pathogenic mutation, and/or less than 20% of control of OTC activity in the liver, and/or elevated urinary orotate (greater than 20 uM/mM) in a random urine sample or after allopurinol challenge test, and/or hyperammonemia and first degree relative meets at least one of the criteria for OTC deficiency * Diagnosis of AS deficiency (Citrullinemia), defined as a greater than or equal to 10-fo