Diseases Studied

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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
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Urea Cycle Disorders Consortium (UCDC)

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Recruiting

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.

Study of how UCDs affect thinking, body chemistry and brain structure using magnetic resonance imaging (MRI) and behavioral testing.

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.

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.

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.

Leads the fight to conquer urea cycle disorders (UCD) and drive critical research to improve outcomes while supporting families.