SNAP: Study Nutrients in Adult PKU (SNAP)

An Exploratory Matched Case-control Study to Measure Blood Nutrient Levels of Adult PKU Patients on a Protein Substitute.

Phenylketonuria (PKU) is a rare inherited metabolic disorder, where subjects are born with a genetic deficiency in the phenylalanine hydroxylase enzyme (PAH), which leaves them unable to convert Phenylalanine (Phe) into Tyrosine (Tyr). PKU patients have specific dietary needs and must follow a restrictive diet in the aim of preventing toxic levels of the amino acid phenylalanine (Phe) accumulation.

Study Overview

• Status: Completed
• Conditions: Phenylketonuria

Detailed Description

The aim of this explorative cross-sectional study is to gain quantitative insights on blood nutrient levels of adult PKU patients on a protein substitute.

• Study Type: Observational
• Enrollment (Actual): 71

Contacts and Locations

• Study Contact: Name: Nutricia Research; Phone Number: +31 30 295000; Email: Register.clinicalresearchnutricia@danone.com

Study Locations

• Belgium
  • Gent, Belgium
    • UZ Gent
• Denmark
  • Copenhagen, Denmark
    • Rigshospitalet
• Spain
  • Santiago De Compostela, Spain
    • University Clinical Hospital
  • Sevilla, Spain
    • Hospital Universitario Virgen Del Rocio

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes

• Sampling Method: Non-Probability Sample

Study Population

PKU subjects (18 years and olders) and non PKU comparisons.

Description

- Inclusion Criteria:

Both PKU and Non-PKU comparison subjects:

1. Age ≥18 years
2. Willing and able to provide signed informed consent PKU specific inclusion criteria
3. PKU patients identified by newborn screening and started low Phe diet before 1 month age

4. Usage of at least one Phe-free protein substitute (i.e. an amino acid mixture including micronutrients) on a daily basis for at least 26 consecutive weeks up to Visit 1

   Non-PKU comparison subjects specific inclusion criteria:

5. Same age- (±3 years) and sex as an included PKU subject

   • Exclusion Criteria:

Both PKU and Non-PKU comparison subjects:

1. For women: Currently pregnant or lactating
2. Current psychiatric disorders
3. Current Substance Use Disorders (as described in DSM V)
4. Current use of psychotropic and/or inotropic medication
5. Omega-3, antioxidant, (multi)vitamin and/or (multi)mineral supplement use within six weeks prior to entry in the study
6. Severe hepatic, thyroid or renal dysfunction
7. No acute illnesses like flu, diarrhea, or vomiting (subjects should be symptom free for a week prior to V1)
8. Participation in any other clinical intervention studies involving test products concomitantly or within six weeks prior to entry into the study

9. Other family members taking part in this study

   PKU subject specific exclusion criteria:

10. Use of BH4, or drugs that may interfere with main outcomes

    Non-PKU comparison subjects specific exclusion criteria:

11. Any condition or special diet (e.g. vegan or vegetarian diet) that effects the metabolism and/or normal dietary pattern/intake
12. A first or second degree relative with inborn errors of metabolism
13. Living together with someone with inborn errors of metabolism (e.g. partner, spouse or roommate)

Study Plan

How is the study designed?

Design Details

• Observational Models: Other
• Time Perspectives: Cross-Sectional

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort
PKU subjects
Age and sex-matched non-PKU comparison subjects

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Blood nutritional status	Micro-and macronutrients and amino acid levels [in a.o. mg/L]	day 1

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Blood nutritional status	Phe/Tyr ratio [µmol/L]	day 1
Nutrient intake	measured by three-day food diary. Nutrients in [mg/day]	day 1 - day 7
Subjective cognitive well-being	measured by FACT-Cog questionnaire: [four domains [score-range): 1) patients' perceived cognitive impairments [0-80]; 2) perceived cognitive abilities [0-36]; 3) noticeability or comments from others [0-16]; 4) impact of cognitive changes on quality of life [0-16]. A summary score is obtained by summing all item scores [0-148].	day 1 - day 7

Collaborators and Investigators

• Sponsor: Nutricia Research

Study record dates

Study Major Dates

• Study Start (Actual): April 15, 2019
• Primary Completion (Actual): March 3, 2023
• Study Completion (Actual): May 15, 2023

Study Registration Dates

• First Submitted: February 27, 2019
• First Submitted That Met QC Criteria: February 27, 2019
• First Posted (Actual): February 28, 2019

Study Record Updates

• Last Update Posted (Actual): June 2, 2023
• Last Update Submitted That Met QC Criteria: June 1, 2023
• Last Verified: September 1, 2021

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Metabolic Diseases; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Genetic Diseases, Inborn; Metabolism, Inborn Errors; Brain Diseases, Metabolic; Brain Diseases, Metabolic, Inborn; Amino Acid Metabolism, Inborn Errors; Phenylketonurias
• Other Study ID Numbers: MBB16TA10778

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No