Urea Cycle Disorders
Conditions
Brief summary
Urea cycle disorders (UCD) are genetic disorders caused by the liver's inability to break down ammonia from proteins; ammonia then accumulates and is toxic to the brain. UCD cause brain damage and intellectual and developmental disabilities and even death. Treatment for UCD is either conservative management which involves a low-in-protein diet, drugs, and amino acid supplements or liver transplantation; each carries their own risks. This study aims to help patients to make the decision about different management alternatives by providing them with scientific information that is currently lacking. Aim 1 of this study will compare survival, neurocognitive function, and patient-reported quality of life.
Detailed description
Urea cycle disorders (UCD) are genetic disorders caused by the liver's inability to break down ammonia from proteins; ammonia then accumulates and is toxic to the brain. UCD cause brain damage and intellectual and developmental disabilities and even death. Treatment involves a special diet low in protein, drugs that help metabolize ammonia and amino acid supplements (conservative management). Many patients and families choose liver transplantation rather than conservative treatment; both alternatives are effective in reducing or normalizing blood ammonia. While liver transplantation eliminates the ammonia problem, conservative management does so only temporarily and in many patients, blood ammonia can rise during an infection. The long-term objective of this study is to help patients make decisions about management alternatives (conservative vs. liver transplantation) by providing them with scientific information that is currently lacking. The questions the investigators will address are: 1. What is the disease's risk of mortality and illness in the two treatment approaches? 2. What can parents expect in terms of the development of their child and his/her school performance? 3. What are the expected effects of each treatment on short-term and long-term quality of life? The investigators will use statistical methods to compare numbers or percentages of survival, illness, psychological testing for IQ, executive function, memory, behaviors, and quality of life among patients that choose conservative management and those who have chosen liver transplantation. Some of this information is already being collected by the Urea Cycle Disorders Consortium (UCDC) in 14 metabolic clinics (11 of them in the US) as part of its long-term follow-up study. To ensure that the information the investigators analyze is representative of the UCD patient population in the US, the investigators will also obtain data from the Studies of Pediatric Liver Transplantation (SPLIT) registry, which collects information about children who undergo liver transplantation for many different diseases (including UCD). The National Urea Cycle Disorders Foundation (NUCDF) and the Patients' Research Working Group collaborated with the clinical investigators to design this research and to ensure that it that it covers the questions that are most important to patients and their families. The results of this study will be disseminated to patients, their doctors, and clinical staff so they receive current, validated information before making a decision about the best treatment for them.
Interventions
Sponsors
Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)
National Center for Advancing Translational Sciences (NCATS)
Patient-Centered Outcomes Research Institute
George Washington University
The National Urea Cycle Disorders Foundation
Studies of Pediatric Liver Transplantation
Children's National Research Institute
Study design
Observational model
COHORT
Time perspective
PROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
No minimum to 18 Years
Healthy volunteers
Yes
Inclusion criteria
Aim 1 (UCD patients): * Age 18 and under * Diagnosed with the following Neonatal-type urea cycle disorders: * CPSD, OTCD, ASD or ALD, as defined as follows: * 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-fold elevation of citrulline in plasma, and/or decreased (less than 20% of control) AS enzyme activity in cultured skin fibroblasts or other appropriate tissue, and/or identification of a pathogenic mutation in the AS gene, and/or hyperammonemia and first degree relative meets at least one of the criteria for AS Deficiency * Diagnosis of AL deficiency (Argininosuccinic Aciduria, ASA), defined as the presence of argininosuccinic acid in the blood or urine, and/or decreased (less than 20% of control) AL enzyme activity in cultured skin fibroblasts or other appropriate tissue, and/or identification of a pathogenic mutation in the AL gene, and/or hyperammonemia and first degree relative meets at least one of the criteria for AL Deficiency * Willing to participate in at least 1 neurocognitive assessment and 1 quality of life assessment * Permit access to medical records and medical providers
Exclusion criteria
Aim 1: * Rare and unrelated comorbidities (e.g., Down's syndrome, intraventricular hemorrhage in the newborn period, and extreme prematurity)
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Mortality | 436 person years in the Liver Transplant Group and 386 person-years in the Without Transplant Group | This aspect of Aim 1 is prospective by design based on selection by exposure (liver transplant or medical managed) evaluating the clinical outcomes of subjects with urea cycle disorders. |
| Neurocognitive Function: Full-Scale IQ | Neuropsychological testing was conducted once for each patient at baseline during the study on age-matched norms for the specific test used. | Neuropsychological tests were based on age-matched norms for the specific test used. All neurocognitive scores have been standardized to the following: norm, mean of 100, and sd of 15. In all tests higher scores are interpreted as higher functions. The WPPSI and WASI were combined to create a single measure of Full-Scale IQ. Full-Scale IQ * Wechsler Preschool and Primary Scales of Intelligence, 4th edition (WPPSI-IV: Children 3-5 years of age) * Wechsler Abbreviated Scales of Intelligence, 1st and 2nd editions (WASI-I & II: Persons 6+ years of age) |
| Total Quality of Life | Quality of life testing was conducted and reported at baseline for each patient during the study. | Quality of life assessments are self-reported by participating patients or by their parent/caretaker using the following reports: Pediatric Family Impact (PedsQL), Version 4 is reported as a total score All were scored on a 0-100 scale. Higher scores indicated a better health-related quality of life |
Countries
United States
Participant flow
Recruitment details
Patients were recruited from the Urea Cycle Disorder Consortium registry study and were recruited from UCDC member hospitals. Recruitment began in April 2016 and ended in April 2019.
Pre-assignment details
No pre-assignment details, this was not an intervention study.
Participants by arm
| Arm | Count |
|---|---|
| Urea Cycle Disorder With Liver Transplant * Age 18 and under
* Diagnosed with the following Neonatal-type urea cycle disorders: CPSD, OTCD, ASD or ALD, as defined as follows:
No Intervention Given
History of liver transplant | 101 |
| Urea Cycle Disorder Without Transplant * Age 18 and under
* Diagnosed with the following Neonatal-type urea cycle disorders: CPSD, OTCD, ASD or ALD, as defined as follows:
No Intervention Given
No history of liver transplant | 86 |
| Total | 187 |
Baseline characteristics
| Characteristic | Urea Cycle Disorder Without Transplant | Urea Cycle Disorder With Liver Transplant | Total |
|---|---|---|---|
| Age, Customized >10 Years | 3 Participants | 4 Participants | 7 Participants |
| Age, Customized 1-5 Years | 35 Participants | 38 Participants | 73 Participants |
| Age, Customized 5-10 Years | 10 Participants | 10 Participants | 20 Participants |
| Age, Customized 6-12 Months | 10 Participants | 29 Participants | 39 Participants |
| Age, Customized <6 Months | 28 Participants | 20 Participants | 48 Participants |
| Ethnicity (NIH/OMB) Hispanic or Latino | 11 Participants | 17 Participants | 28 Participants |
| Ethnicity (NIH/OMB) Not Hispanic or Latino | 62 Participants | 77 Participants | 139 Participants |
| Ethnicity (NIH/OMB) Unknown or Not Reported | 13 Participants | 7 Participants | 20 Participants |
| Sex: Female, Male Female | 33 Participants | 34 Participants | 67 Participants |
| Sex: Female, Male Male | 53 Participants | 67 Participants | 120 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 0 / 101 | 0 / 86 |
| other Total, other adverse events | 0 / 101 | 0 / 86 |
| serious Total, serious adverse events | 0 / 101 | 0 / 86 |
Outcome results
Primary
Mortality
This aspect of Aim 1 is prospective by design based on selection by exposure (liver transplant or medical managed) evaluating the clinical outcomes of subjects with urea cycle disorders.
Time frame: 436 person years in the Liver Transplant Group and 386 person-years in the Without Transplant Group
Population: Treatment-related effects on mortality
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| Urea Cycle Disorder With Liver Transplant | Mortality | 18.4 participant per 1000 person-years |
| Urea Cycle Disorder Without Transplant | Mortality | 20.7 participant per 1000 person-years |
Primary
Neurocognitive Function: Full-Scale IQ
Neuropsychological tests were based on age-matched norms for the specific test used. All neurocognitive scores have been standardized to the following: norm, mean of 100, and sd of 15. In all tests higher scores are interpreted as higher functions. The WPPSI and WASI were combined to create a single measure of Full-Scale IQ. Full-Scale IQ * Wechsler Preschool and Primary Scales of Intelligence, 4th edition (WPPSI-IV: Children 3-5 years of age) * Wechsler Abbreviated Scales of Intelligence, 1st and 2nd editions (WASI-I & II: Persons 6+ years of age)
Time frame: Neuropsychological testing was conducted once for each patient at baseline during the study on age-matched norms for the specific test used.
Population: * Full Scale IQ~* WPPSI - Children 3-5 years of age~* WASI - Persons 6+ years of age
| Arm | Measure | Value (MEAN) |
|---|---|---|
| Urea Cycle Disorder With Liver Transplant | Neurocognitive Function: Full-Scale IQ | 80.1 score on a scale |
| Urea Cycle Disorder Without Transplant | Neurocognitive Function: Full-Scale IQ | 82 score on a scale |
Primary
Total Quality of Life
Quality of life assessments are self-reported by participating patients or by their parent/caretaker using the following reports: Pediatric Family Impact (PedsQL), Version 4 is reported as a total score All were scored on a 0-100 scale. Higher scores indicated a better health-related quality of life
Time frame: Quality of life testing was conducted and reported at baseline for each patient during the study.
Population: Patient/family reported quality of life using PedsQL quality of life measuremet tool (version 4)
| Arm | Measure | Value (MEAN) |
|---|---|---|
| Urea Cycle Disorder With Liver Transplant | Total Quality of Life | 69.8 score on a scale of 0-100 |
| Urea Cycle Disorder Without Transplant | Total Quality of Life | 55.6 score on a scale of 0-100 |