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All Diseases > Argininosuccinate Synthetase Deficiency
Argininosuccinate Synthetase Deficiency (ASSD)
Alternative Names: Citrullinemia I
Disease Category: Urea Cycle Disorders
An inherited, metabolic, urea cycle disorder characterized by hyperammonemia (high blood ammonia levels) due to deficiency or absence of an enzyme needed to convert nitrogen from protein metabolism (break down) into urea (a waste product). Symptoms include vomiting, feeding and growing problems, fatigue, seizures, hypotonia (low muscle tone), hepatomegaly (enlarged liver), liver failure, respiratory distress, cerebral edema (fluid accumulation increasing pressure around the brain), coma, ataxia (lack of coordination), developmental delay, intellectual disability, and behavioral changes.
Research groups studying this disease
Urea Cycle Disorders
Urea Cycle Disorders Consortium (UCDC)View Disease Definition
5101: Longitudinal Study of Urea Cycle Disorders
Long-term observation of the impact of UCDs on physical and neurological functioning, the relationship between health indicators and disease severity and the eﬃciency of UCD therapies.
5113: Biomarkers of Neurological Injury and Recovery in Urea Cycle Disorders
Study of how UCDs aﬀect thinking, body chemistry and brain structure using magnetic resonance imaging (MRI) and behavioral testing.
5119: Electrographic Seizures in Hyperammonemia
The purpose of this research is to determine if silent seizures (electrographic seizures) occur during a hyperammonemic (HA) episode in patients with urea cycle disorders (UCD). Urea cycle disorders lead to accumulation increased ammonia due to problems breaking down protein. The symptoms of UCD may present at birth, childhood or adulthood (milder deficiencies) and are associated with cognitive deficits, changes in behavior, brain swelling and seizures. Sometime the seizures are not clinically obvious, but can be picked up if a video recording and concurrent EEG (video EEG is used, cVEEG). cVEEG is used in many intensive care units across the country to pick up seizures. We want to determine if having seizures due to HA leads to any adverse cognitive outcomes, and want to use the EEG to identify any changes that may be associated with that.
5120: Noninvasive Biomarkers of Hepatic Fibrosis in Urea Cycle Disorders
The purpose of this study is to measure liver stiffness and chemicals in the blood that test liver injury and function in four urea cycle disorders. Sometimes the seizures are not clinically obvious, but can be picked up if a video recording and concurrent EEG (video EEG is used, cVEEG). cVEEG is used in many intensive care units across the country to pick up seizures. We want to determine if having seizures due to HA leads to any adverse cognitive outcomes, and want to use the EEG to identify any changes that may be associated with that.
5121: Neurodevelopmental Assessments in the Longitudinal Study of Urea Cycle Disorders: Comparison of Standard (Traditional) Neuropsychological Battery and NIH Toolbox
We are doing this study to see how the results of two sets of tools used to measure developmental progress relate to one another and how acceptable completing each of these measures is to children and families of children with Urea Cycle Disorders. We are anxious to make longitudinal assessment (repeated observations over time) of cognition easier, quicker and more accessible for families of children with urea cycle disorders. In order to do so we want to understand the relationship between the 2 sets of measures.
5123: Novel food photography method to measure dietary intake in patients with UCDs
The purpose of this research study is to test a new method to measure food intake using smart phone photos of your food before and after meals. We will compare the smart phone food photos to a 3-day diet record and we will measure how many calories you burn.
National Urea Cycle Disorders Foundation
Leads the fight to conquer urea cycle disorders (UCD) and drive critical research to improve outcomes while supporting families.