Dwarfism, Growth Hormone Deficiency, Healthy Volunteers, Hypotonia-Cystinuria Syndrome, Muscle Hypotonia, Obesity, Prader-Willi Syndrome
Conditions
Brief summary
Evaluation of PREPL activity in healthy controls and known or possible PREPL deficient patients
Detailed description
PREPL is defective in hypotonia cystinuria syndrome and in isolated PREPL deficiency. The investigators have constructed a blood test to evaluate PREPL activity in patients with possible PREPL deficiency. The study will determine normal values for age (0-18) for PREPL activity in blood. Also, patients with a clinical phenotype that overlaps with PREPL deficiency (including patients with known primary PREPL deficiency and Prader-Willi syndrome) will be evaluated for PREPL activity in blood. A last part of the study will involve muscle biopsies during elective anesthesia/surgery for other reasons. There will be 2 groups: patients without signs of PREPL deficiency undergoing surgery (controls) and patients with Prader-Willi syndrome undergoing anesthesia or surgery (patients). The control group will be age-matched to the hypotonia group. In the muscle biopsies, PREPL activity and expression will be evaluated.
Interventions
PROCEDUREBlood draw
Blood draw
PROCEDUREmuscle biopsy
Muscle biopsy during planned anesthesia/surgery
Sponsors
KU Leuven
Universitaire Ziekenhuizen KU Leuven
Study design
Allocation
NON_RANDOMIZED
Intervention model
PARALLEL
Primary purpose
DIAGNOSTIC
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
No minimum to 40 Years
Healthy volunteers
Yes
Inclusion criteria
* According to group * Control group: children seen at a postinfectious consultation
Exclusion criteria
* Control group: symptoms overlapping with PREPL deficiency, genetic or syndromic disease, atypically developing children * other groups: contraindication for blood draw * group with muscle biopsy: contra-indication for muscle biopsy
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| PREPL activity (ng active PREPL/g protein) normal values in blood | 3 months | normal values for PREPL activity |
| PREPL activity in patients with Prader Willi syndrome compared to activity in normal controls | 3 months | Comparison of PREPL activity in blood and muscle between above mentioned groups |
| PREPL activity in patients with primary PREPL deficiency compared to activity in normal controls | 3 months | Comparison of PREPL activity in blood between above mentioned groups |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| PREPL activity in patients with muscle weakness/obesity/growth hormone deficiency compared to activity in normal controls | 3 months | exploratory evaluation |
Countries
Belgium
Outcome results
None listed