Phenylalanine hydroxylase deficiency
Conditions
Interventions
13C-Pheylalanine breath test
Sponsors
Universitair Medisch Centrum Groningen
Eligibility
Age
2 Years to 64 Years
Inclusion criteria
Inclusion criteria: Part A (healthy adult volunteers) In order to be eligible to participate in this study, a subject must meet all of the following criteria: - At least 16 years old. Part B (adults with PKU) In order to be eligible to participate in this study, a subject must meet all of the following criteria: - At least 16 years old. - Diagnosed with PKU. - Known genetic mutation of the PAH gene. - Able to comply with the study protocol as assessed by their treating physician (e.g. being able to comply with fasting overnight and remain rested during the 13C-PBT). - For females: a regular menstrual cycle (of approximately 4 weeks) OR post-menopausal. To be able to reach our secondary objective, it is necessary to include patients with different phenotypes. Phenotypes of PKU patients can be expressed by their genotypic phenotype values (GPV), which is a numerical representation of PAH activity (and thus disease severity) that depends on the genotype of the patient. An online database (http://www.biopku.org) provides GPVs for almost all different genotypes (15). Of the 10-20 patients to be included in part B, we aim to include >= 2-5 patients with classic PKU (GPV: 0-2.7), >= 2-5 patients with mild PKU (GPV: 2.8-6.6), and >= 2-5 patients with mild hyperphenylalaninemia (GPV: 6.7-10.0). Part C (children with PKU) In order to be eligible to participate in this study, a subject must meet all of the following criteria: - >= 6 years and <16 years old. - Diagnosed with PKU. - Known genetic mutation of the PAH gene. - Able to comply with the study protocol as assessed by their treating physician (e.g. being able to comply with fasting overnight and remain rested during the 13C-PBT). - For females: a regular menstrual cycle (of approximately 4 weeks) OR pre-menarchic. Similar to part B, we aim to include >= 2-5 patients with classic PKU (GPV: 0-2.7), >= 2-5 patients with mild PKU (GPV: 2.8-6.6), and >= 2-5 patients with mild hyperphenylalaninemia (GPV: 6.7-10.0).
Exclusion criteria
Exclusion criteria: Part A, B and C A potential subject who meets any of the following criteria will be excluded from participation in this study: - Pregnancy or wishing to become pregnant. - Known liver and/or kidney dysfunction. - Use of medication that may influence liver and/or kidney function.
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| The test-retest reliability of the 13C-PBT for measuring Phe hydroxylation, expressed as the intraclass correlation coefficient (ICC). | — |
Secondary
| Measure | Time frame |
|---|---|
| - The relationship between Phe hydroxylation as measured by the 13C-PBT and the genotypic phenotype values (GPV), as a measure of disease severity. - A description (mean with 95% confidence interval) of the outcomes of the 13C-PBT in healthy persons. | — |
Countries
Netherlands
Contacts
Public ContactS Haitjema
Universitair Medisch Centrum Groningen
Outcome results
None listed