Neurocognitive Outcomes in Mild Hyperphenylalaninemia Study
Phenylketonuria is a genetic disorder known to cause severe reduction in intelligence and deficits in cognitive function; it is associated with an elevated level of Phenylalanine (Phe) in blood. Newborn screening and early treatment with restricted protein diet supplemented by a formula of amino-acids will preserve intelligence. In those with the severe form treated from birth, some deficits that affect higher functions of the brain are seen. Given this, there is disagreement about how milder forms of this disease should be managed and what level of Phe is safe to be left untreated. We seek to assess whether higher levels, between 360 and 600µmol/L, are safe with respect to preservation of intelligence and higher cognitive functions.
|Study Design:||Observational Model: Case Control
Time Perspective: Prospective
|Official Title:||Neuropsychological and Quality of Life Outcomes in Untreated Adults With Mild Hyperphenylalaninemia With Phenylalanine Levels Between 360 and 600 µmol/L.|
- Executive function [ Time Frame: Day 1 ] [ Designated as safety issue: No ]As measured by subtests in Weschler-IV test, and supplemented with assessments from BRIEF-A and CANTAB
- Quality of Life [ Time Frame: Day 1 ] [ Designated as safety issue: No ]
- Presence of anxiety and depression [ Time Frame: Day 1 ] [ Designated as safety issue: Yes ]As measured by Beck Anxiety and Depression Inventories
- IQ [ Time Frame: Day 1 ] [ Designated as safety issue: No ]As measured by Wechsler-IV
|Study Start Date:||September 2013|
|Estimated Study Completion Date:||July 2014|
|Estimated Primary Completion Date:||July 2014 (Final data collection date for primary outcome measure)|
With Phe between 360 and 600 micromoles/L
With normal Phe levels
The following personal/medical information will be collected and reviewed:
- Evaluation of current and past medical history, including psychological treatment such as medication and counseling/therapy.
- Mutational analysis for each MHP subject
- Detailed history of educational, employment, relationship, and socioeconomic status/achievements as a measure of successful transition to adulthood
- Diet history, including past treatment with medical food or Sapropterin (Kuvan) for pre-conceptual and pregnancy Phe management
- All available untreated Phe levels, including newborn screening results (where possible) will be collated to calculate lifetime mean Phe level. Age at collections will be recorded separately for each MHP subjects to ensure inclusion of Phe levels beyond infancy
The following clinical investigations will be administered:
- Measurement of Phe and Tyr after an overnight fast, via blood spot using tandem mass spectrometry analysis. Blood spot collection will be done at the same time of day for all subjects.
- Physical exam, height and weight measurements
- Food Frequency Questionnaire assessment to estimate typical daily intake of natural protein.
- Beck Anxiety Inventory
- Beck Depression Inventory
- Quality of Life questionnaire
Neuropsychological Tests assessed by a trained psychologist:
- Wechsler-IV IQ test (Canadian Version)
- Choice Reaction Time (CRT)
- Rapid Visual Information Processing (RVP)
- Spatial Span (SSP)
- Spatial Working Memory (SWM)
- Stockings of Cambridge (SOC)
An informant BRIEF-A report will be completed for each subject. To ensure consistency in rating, the same informant will be used where possible for the MHP subject and their sibling control (i.e. parents). These questionnaires will be mailed to the informants and returned to the study site via FedEx.
|Contact: Komudi Siriwardena, MDfirstname.lastname@example.org|
|Contact: Ashley Orton||416-813-7654 ext email@example.com|
|The Hospital for Sick Children||Not yet recruiting|
|Toronto, Ontario, Canada, M5G 1X8|
|Principal Investigator: Komudi Siriwardena, MD|
|Principal Investigator:||Komudi Siriwardena, MD||The Hospital for Sick Children|