Biological Variation of Phenylalanine in Patients With Hyperphenylalaninemia (NCT01869972) | Clinical Trial Compass
CompletedNot Applicable
Biological Variation of Phenylalanine in Patients With Hyperphenylalaninemia
Canada32 participantsStarted 2013-05
Plain-language summary
Phenylketonuria (PKU) is a rare disease where the level of phenylalanine (one of the amino acids) in the body is greatly increased. High levels can cause brain damage, especially in babies and children. This brain damage can be prevented if a special low phenylalanine diet is started soon after birth. A new drug, sapropterin, can also lower phenylalanine levels in some patients. PKU therapy is monitored by measuring the blood phenylalanine every week, with the goal to keep the level within a target range. Recently, studies have suggested that the variation in the blood phenylalanine may be just as important as the absolute blood phenylalanine level for brain outcome.
The investigators will look at the variation in blood phenylalanine level over 24 hours to see how much the level changes. The investigators will measure this in patients with typical PKU who are compliant with the diet and in patients who are not compliant with the diet. The investigators will also measure this in patients with "mild" PKU who do not usually have as high levels of phenylalanine. Finally, the investigators will see if patients on sapropterin have lower variation.
Who can participate
Age range
4 Years
Sex
ALL
See this in plain English?
AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.
Inclusion Criteria:
• Subjects ≥4 years of age with hyperphenylalaninemia. Must have at least 1 documented blood phenylalanine level \>600 µmol/L for study groups (Wide PHE, Target PHE, Kuvan groups) or \>120 µmol/L for control group.
Exclusion Criteria:
* Significant cognitive impairment (IQ \<70 or clinical judgment).
* Pregnancy
* Other specific PKU therapies, including enzyme replacement therapy or any amino acid supplement designed to block uptake or transport of phenylalanine (i.e. large neutral amino acid mixtures)
* Any intercurrent illness within the previous 5 days (any of fever, vomiting, diarrhea, decreased intake, upper respiratory tract infection).
Questions worth asking your doctor
Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.
1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?
Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.
Questions for the trial coordinator
The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.
1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?
A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.
What they're measuring
1
Standard deviation of blood phenylalanine level (sdPHE)