An observational study in Inborn Errors of Metabolism and Epilepsy (Treatment Refractory), sponsored by University Children's Hospital, Zurich. Not yet recruiting. Open to participants aged 4 Years and older, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-08-12.
Sponsored by University Children's Hospital, Zurich · Observational
In patients with inborn errors of metabolism (IEM) and in those requiring a ketogenic diet for the treatment of medical conditions, relevant biochemical analytes are routinely and regularly measured in venous or capillary blood samples. Repeated venipuncture for blood collection is invasive, burdensome, and resource-intensive. As an alternative, capillary blood sampling can provide some relief for the measurement of a limited number of metabolites. Nevertheless, the frequent finger pricks required to obtain capillary blood samples can still be uncomfortable for patients. Therefore, patients could benefit if non-invasive breath measurements were to replace the currently invasive biochemical monitoring methods in the future.
In this study, the usability of metabolite measurements across matrices (venous blood, capillary blood, breath captured by a handheld sensor and breath in a collection bag) in IEM patients, individuals prescribed special health-related diets, and healthy volunteers will be investigated. The usability of a handheld breath sensor for remote monitoring of patients will also be tested. Lastly, exploratory investigations will be performed to identify new disease biomarkers in breath.
152 studies on the registry are indexed under Metabolism, Inborn Errors; 22 are open to participants now.
This study's planned enrollment of 100 is above the median of 65 across 45 observational studies indexed under Metabolism, Inborn Errors.
Browse Metabolism, Inborn Errors studies →University Children's Hospital, Zurich is the lead sponsor of 95 studies on the registry; 23 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Patients who are routinely cared for at the study site will be invited to participate. Healthy volunteers will be recruited through communication with healthy family members accompanying patients to hospital visits and the general population through flyers.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Relapsed: the illness came back after treatment had worked. Refractory: it did not respond to treatment, or stopped responding while still on it.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Relapsed and refractory
Relapsed: the illness came back after treatment had worked. Refractory: it did not respond to treatment, or stopped responding while still on it.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Other: Observational Study
no intervention
Concentration (μmol/L) of metabolites of clinical interest in venous blood, capillary blood and breath of participants.
1. Concentration of beta-hydroxybutyrate in venous and capillary blood 2. Concentration of acetone in exhaled breath 3. Concentration of ammonia in venous blood and exhaled breath 4. Concentration of amino acids (alanine, arginine, asparagine, aspartic acid, citrulline, cysteine, glutamine, glutamic acid, glycine, histidine, isoleucine, leucine, lysine, methionine, ornithine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine and valine) in venous blood, capillary blood and exhaled breath.
Time frame: Baseline
Correlation of metabolite concentrations in different matrices
1. Correlation between concentration of beta-hydroxybutyrate in venous and capillary blood and concentration of acetone in exhaled breath captured directly by a handheld device with a chemiresistor sensor and breath captured in a collection bag and measured by mass spectrometry 2. Correlation between concentration of ammonia in venous blood and exhaled breath captured directly by a handheld device with a chemiresistor sen 3. Correlation between concentration of amino acids in venous and capillary blood and in exhaled breath captured directly by a handheld device with a chemiresistor sensor and breath captured in a collection bag and measured by mass spectrometry
Time frame: Baseline
Participant self-report questionnaire on a 4-point Likert scale on the burden of each sampling method
Likert scale: 1, Strongly Agree. 2, Agree. 3, Disagree. 4, Strongly Disagree. The lower the score, the lower the burden of sampling method.
Time frame: Baseline
Participant self-report questionnaire on a 4-point Likert scale on the usability of the handheld breath sensor for remote measurements of metabolites
Likert scale: 1, Strongly Agree. 2, Agree. 3, Disagree. 4, Strongly Disagree. The lower the score, the higher the acceptance of using the handheld breath sensor.
Time frame: Baseline
Untargeted SESI-based mass spectrometry analysis of exhaled breath captured in a bag
abundance (parts per million) of all detectable and identifiable metabolites in exhaled breath
Time frame: Baseline
No study locations are listed for this record.
Plan to share: Undecided
No publications or documents are linked to this record.
Start is estimated for Oct 2026; primary completion for Oct 2036, 120 months later.
How these figures are worked out, and which studies are left out of them.
This study is not yet recruiting, as verified in Aug 2026. You cannot join it, but the record below documents what was studied.
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University Children's Hospital, Zurich