The reliability of the 13C-phenylalanine breath test for phenylketonuria patients: a pilot study

• Conditions: Phenylalanine hydroxylase deficiency; phenylketonuria; PKU.; 10027424

• Registration Number: NL-OMON52773
• Lead Sponsor: niversitair Medisch Centrum Groningen

Brief Summary

Not available

Detailed Description

Not available

Study Timeline

• Last Update Posted: 15 April 2024

Recruitment & Eligibility

• Status: Pending
• Sex: Not specified
• Target Recruitment: 50

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.
- Not receiving pharmacological treatment with BH4.
- 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 20 patients to be included in part B, we
aim to include >= 5 patients with classic PKU (GPV: 0-2.7), >= 5 patients with
mild PKU (GPV: 2.8-6.6), and >= 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.
- Not receiving pharmacological treatment with BH4.
- 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 >= 5 patients with classic PKU (GPV:
0-2.7), >= 5 patients with mild PKU (GPV: 2.8-6.6), and >= 5 patients with mild
hyperphenylalaninemia (GPV: 6.7-10.0).

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.

Study & Design

• Study Type: Observational invasive
• Study Design: Not specified