ArticleJIMD reports2017
Improved Measurement of Brain Phenylalanine and Tyrosine Related to Neuropsychological Functioning in Phenylketonuria.
Article in JIMD reports, 2017. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 8 papers, 1 of them a synthesis that pooled it.
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Who cites it
8 citing papers in PubMed, 1 synthesis or guideline pooled it, 21 citations in OpenAlex.
- Characterisation and differential diagnosis of neurological complications in adults with phenylketonuria: literature review and expert opinion.Journal of neurology · 2023Pooled it
- Treatment goals for adults with early treated PKU should be determined by evidence-based shared decision making between patients and their medical team.Orphanet journal of rare diseases · 2026Article
- Two adult sisters with untreated phenylketonuria: Strikingly discordant clinical phenotype.Molecular genetics and metabolism reports · 2026Article
- Diffusivity alterations related to cognitive performance and phenylalanine levels in early-treated adults with phenylketonuria.Journal of neurodevelopmental disorders · 2025Article
- Cognition and wellbeing in middle-aged early treated people with phenylketonuria: Preliminary results and methodological lessons.Molecular genetics and metabolism reports · 2024Article
- Blood phenylalanine reduction reverses gene expression changes observed in a mouse model of phenylketonuria.Scientific reports · 2021Article
- The rs113883650 variant ofMolecular genetics and metabolism reports · 2021Article
- New protein structures provide an updated understanding of phenylketonuria.Molecular genetics and metabolism · 2017Review
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Authors and funding
10 authors at 4 institutions in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
introductionResearchers hypothesized that in phenylketonuria (PKU) high brain phenylalanine (Phe) levels and low brain tyrosine (Tyr) levels affect neuropsychological functioning. However, traditional magnetic resonance spectroscopy (MRS) yielded uncertain results of brain Phe and could not adequately measure brain Tyr. This pilot study examined the potential of correlated spectroscopy (COSY) to quantify these biomarkers and explain variability in neuropsychological functioning.
methodsNine adults with early treated classic PKU received magnetic resonance imaging (MRI) with COSY and a battery of neuropsychological tests. Brain Phe and Tyr in parietal white matter (PWM) were compared to results in gray matter of the posterior cingulate gyrus (PCG).
resultsBrain Phe ranged from 101 to 182 (mean = 136.76 ± 23.77) μmol/L in PCG and 76 to 185 (mean = 130.11 ± 37.88) μmol/L in PWM. Brain Tyr ranged from 4.0 to 7.4 (mean = 5.44 ± 1.01) μmol/L in PCG and 4.1 to 8.4 (mean = 5.90 ± 1.48) μmol/L in PWM. Correlation coefficients were largest for brain Phe PWM and measures of auditory memory (rho = -0.79), anxiety (rho = 0.79), and executive functioning (rho = 0.69). Associations were in the expected direction, with higher brain Phe and lower brain Tyr related to poorer functioning. The two participants with severe structural MRI abnormalities had low brain Tyr levels in PCG and 3/5 of the participants with moderate to severe MRI abnormalities had higher than average brain Phe levels.
conclusionCOSY has the potential to quantify brain Phe and Tyr at low concentrations and in specific brain regions. In this pilot study, these biomarkers were associated with indices of neuropsychological functioning. Additional studies are needed to validate the COSY results.
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