ClinicalTrials.gov record NCT05128149

Metabolic Control and Patient Well-being in Phenylketonuria: do Guidelines Make a Difference?

Record copied from ClinicalTrials.gov: Oct 10, 2026AI summaries generated: Sep 6, 2026

About this page. This page shows the study's official ClinicalTrials.gov record ↗, with added help to make it easier to understand. We explain medical terms, highlight key details in plain language, and suggest questions you may want to ask the study team.

The record is periodically copied from ClinicalTrials.gov and may lag behind changes. AI summaries are checked by software, not a clinician.Read moreShow less

The official record is written by the study sponsor and published on ClinicalTrials.gov. It may not always reflect the latest changes. Before making any decisions, please confirm important information with the study team and your own healthcare team.

Where you see "AI summary", AI was used to create a plain-language explanation and software checked it against the source. It has not been reviewed by a clinician, so it may contain mistakes or leave out important details.

StatusRecruitingThe study is currently enrolling participants. Only the study team can say whether a particular person can join.

Study typeObservationalA study in which researchers do not assign participants to a treatment or other intervention. They observe or measure what happens, which may include study visits, tests, questionnaires or a review of medical records.

Age10 years old and older

SexAll

LocationSwitzerland

AI summaryWhat this study is about, in plain languageShow ▾Hide ▴

AI-written from the registry record, not the study's own wording. May contain errors or omissions. Check the registry text on this page and the original record ↗ before acting on it.

This observational study looks at metabolic control, treatment adherence, and well‑being in people with phenylketonuria (PKU). It uses past Phe lab results and questionnaires about quality of life, self‑efficacy, and family burden. The study involves people with PKU aged 10 and older and parents of children with PKU.

What it is studying. The study is examining relationships between metabolic control (phenylalanine levels), adherence to PKU treatment, patients' health‑related quality of life, self‑efficacy for managing PKU, and the burden on families. It compares these measures among patients treated at centres that follow different local guidelines.

What the researchers hope to learn. To describe and compare metabolic control, adherence, health‑related quality of life, self‑efficacy, and family burden in people with PKU treated under different local guidelines.

What this study is about

The study's own summary, as published on ClinicalTrials.gov. Underlined terms have a short explanation.

Treatment of PKU implies for most patients that with strict adherence to dietary treatment they can achieve excellent neurocognitive outcome. Dietary treatment, though, is hard to comply to every day and with every single meal. Unsurprisingly, health-related quality of life (HrQol) is negatively affected if patients have to follow a dietary regime of this kind. Adherence to treatment in PKU is very variable. Factors of significant impact on adherence to treatment and well-being in chronic disease such as self-efficacy or parenting stress have not yet been widely investigated in PKU patients. The ideal treatment prescription (and guideline) recommends as much as necessary and as little as possible, based on the best evidence available. Patients should neither be deprived of treatment options nor be exposed to overtreatment. This study investigates adherence, metabolic control, HrQol in PKU patients treated by centres which follow different guidelines

Interventions being studied

Being studied in this trial does not mean the treatment or procedure is approved or available for this condition.

Other: no intervention

Eligibility

The criteria exactly as listed on ClinicalTrials.gov. Only the study team can say whether they apply to you.

Inclusion criteria

Patients with PKU from age 10 years requiring dietary and / or pharmacological treatment according to locally applied guidelines
Parents of patients with PKU aged 10 to 18 years requiring dietary and / or pharmacological treatment according to locally applied guidelines
Ability and willingness to answer the questionnaires and follow the study procedures
Informed consent as documented by signature

Exclusion criteria

for patients and parents :
Inability to follow the procedures of the study, e.g. due to language problems or severely reduced health status
Pregnant patients or patients who have disclosed to their physician that they are planning a pregnancy in the near future
Hyperphenylalaninaemia or mild forms of PKU or other inborn errors associated with elevated Phe but not requiring dietary and / or pharmacological treatment according to locally applied guidelines
No inform

Study description and what participation involves

The registry record has no detailed description beyond the summary above.

AI summaryWhat participation may involve, in plain languageShow ▾Hide ▴

AI-written from the registry record, not the study's own wording. May contain errors or omissions. Check the registry text on this page and the original record ↗ before acting on it.

You would give informed consent and allow the study team to collect your phenylalanine (Phe) lab results from the past 24 months (as reported in medical records). You (and parents of 10–18-year-olds) will complete questionnaires: the PKU‑QoL, a 10‑item self‑efficacy scale, and — for parents of minors — the Revised Impact on Family Scale; each questionnaire is listed with about a one‑hour time frame. The study is observational and does not provide an experimental treatment; it collects existing clinical data and questionnaire responses at a single time point. The registry record does not describe any additional procedures, extra visits, or participant services.

How the study is structured. This is an observational, cross‑sectional cohort study with no treatment given (no intervention). Researchers will collect participants' reported phenylalanine (Phe) measurements from the past 24 months and ask participants to complete questionnaires: the PKU‑QoL questionnaire, a 10‑item self‑efficacy scale, and for parents of 10–18 year‑olds the Revised Impact on Family Scale. The registry lists each questionnaire with a time frame of about one hour.

Questions you could ask

These questions are suggestions for a conversation with the study team or your own clinician, not advice.

This is an observational study, so the study itself gives no treatment. What would taking part involve for me, and would it change my usual care?
The listed sites are in Switzerland. Is any of them reachable for me, and does the study help with travel?
Which of the eligibility criteria would need to be checked with tests before I could join?

More on phenylketonuria

Clinical trials38 trials listed for phenylketonuriaEvery trial the registry lists for phenylketonuria, with recruitment status, phase and sites, updated from ClinicalTrials.gov.See all trials →Research updatesWhat changed in phenylketonuria researchLatest monthly update: September 2026. Includes: Diet supply gaps. New research summarized each month in plain language, with links to every source paper.Read the latest update →

Important dates

Study start: Nov 15, 2021
Primary completion: Mar 30, 2025
Study completion: Dec 31, 2025 (estimated)
Target enrollment: 200 participants (estimated)
Last updated on registry: Apr 13, 2025
Data verified: Oct 10, 2026

Sponsor and research team

The lead sponsor funds and oversees the trial. A pharmaceutical or biotech company sponsor typically means the study is testing that company's drug or device; a hospital, university, or government agency usually indicates investigator-initiated or publicly funded research.

Lead sponsor: University Children's Hospital, Zurich
Collaborators: UChildrenVienna
University Children's Hospital Basel
Insel Gruppe AG, University Hospital Bern

Central study contact

If you're interested in participating, the central contact can answer general questions about the study — including eligibility requirements and how to find a recruiting site near you. Actual eligibility is determined by the site's medical team.

Martina Huemer, Prof 📞 +41 44 2660 ✉ martina.huemer@kispi.uzh.ch

Participating sites (1)

University Childrens Hospital ZürichRecruiting
Zurich, 8032 · Switzerland
- Martina Huemer, Prof · +41442667593 · martina.huemer@kispi.uzh.ch

Terms used on this page · explanations by MedicalUpdates.ai

Informed consent: The process of explaining a study, including its risks and what participation involves, so that a person can decide freely whether to take part. Consent is usually documented in writing, and a participant can choose to leave the study later.
Inclusion Criteria: The conditions a person must meet to be considered for the study, for example a confirmed diagnosis, an age range or a test result.
Exclusion criteria: The conditions that rule a person out even if they meet the inclusion criteria, for example other illnesses, certain medicines or pregnancy.

The study record on this page is reproduced from ClinicalTrials.gov, a database of the U.S. National Library of Medicine, where it was submitted by the study sponsor. MedicalUpdates.ai does not own this content, is not affiliated with or endorsed by ClinicalTrials.gov, NIH, or the U.S. Government, and does not verify the record. Plain-language notes, the glossary and the questions above are added by this site; text in the boxes marked "AI summary" was written by an AI model and may contain errors. Registry records change over time. Check the original record for the current version and discuss eligibility or participation with a qualified healthcare professional.

← Back to clinical trials