Publications by authors named "Roelineke J Lunsing"

28 Publications

  • Page 1 of 1

Homozygous UBA5 Variant Leads to Hypomyelination with Thalamic Involvement and Axonal Neuropathy.

Neuropediatrics 2021 Apr 14. Epub 2021 Apr 14.

Department of Child Neurology, Amsterdam Leukodystrophy Center, Emma Children's Hospital, Amsterdam UMC, and Amsterdam Neuroscience, Vrije Universiteit, Amsterdam, The Netherlands.

The enzyme ubiquitin-like modifier activating enzyme 5 (UBA5) plays an important role in activating ubiquitin-fold modifier 1 (UFM1) and its associated cascade. is widely expressed and known to facilitate the post-translational modification of proteins. Variants in and are involved in neurodevelopmental disorders with early-onset epileptic encephalopathy as a frequently seen disease manifestation. Using whole exome sequencing, we detected a homozygous variant (c.895C > T p. [Pro299Ser]) in a patient with severe global developmental delay and epilepsy, the latter from the age of 4 years. Magnetic resonance imaging showed hypomyelination with atrophy and T2 hyperintensity of the thalamus. Histology of the sural nerve showed axonal neuropathy with decreased myelin. Functional analyses confirmed the effect of the Pro299Ser variant on UBA5 protein function, showing 58% residual protein activity. Our findings indicate that the epilepsy currently associated with variants may present later in life than previously thought, and that radiological signs include hypomyelination and thalamic involvement. The data also reinforce recently reported associations between variants and peripheral neuropathy.
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http://dx.doi.org/10.1055/s-0041-1724130DOI Listing
April 2021

Consensus guidelines for the diagnosis and management of pyridoxine-dependent epilepsy due to α-aminoadipic semialdehyde dehydrogenase deficiency.

J Inherit Metab Dis 2021 Jan 1;44(1):178-192. Epub 2020 Dec 1.

Department of Child Health, Faculty of Medicine, Universitas Indonesia, Jakarta, Indonesia.

Pyridoxine-dependent epilepsy (PDE-ALDH7A1) is an autosomal recessive condition due to a deficiency of α-aminoadipic semialdehyde dehydrogenase, which is a key enzyme in lysine oxidation. PDE-ALDH7A1 is a developmental and epileptic encephalopathy that was historically and empirically treated with pharmacologic doses of pyridoxine. Despite adequate seizure control, most patients with PDE-ALDH7A1 were reported to have developmental delay and intellectual disability. To improve outcome, a lysine-restricted diet and competitive inhibition of lysine transport through the use of pharmacologic doses of arginine have been recommended as an adjunct therapy. These lysine-reduction therapies have resulted in improved biochemical parameters and cognitive development in many but not all patients. The goal of these consensus guidelines is to re-evaluate and update the two previously published recommendations for diagnosis, treatment, and follow-up of patients with PDE-ALDH7A1. Members of the International PDE Consortium initiated evidence and consensus-based process to review previous recommendations, new research findings, and relevant clinical aspects of PDE-ALDH7A1. The guideline development group included pediatric neurologists, biochemical geneticists, clinical geneticists, laboratory scientists, and metabolic dieticians representing 29 institutions from 16 countries. Consensus guidelines for the diagnosis and management of patients with PDE-ALDH7A1 are provided.
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http://dx.doi.org/10.1002/jimd.12332DOI Listing
January 2021

Disease characteristics of MCT8 deficiency: an international, retrospective, multicentre cohort study.

Lancet Diabetes Endocrinol 2020 07;8(7):594-605

Department of Diabetes and Endocrinology, Women's and Children's Hospital, North Adelaide, SA, Australia.

Background: Disordered thyroid hormone transport, due to mutations in the SLC16A2 gene encoding monocarboxylate transporter 8 (MCT8), is characterised by intellectual and motor disability resulting from cerebral hypothyroidism and chronic peripheral thyrotoxicosis. We sought to systematically assess the phenotypic characteristics and natural history of patients with MCT8 deficiency.

Methods: We did an international, multicentre, cohort study, analysing retrospective data from Jan 1, 2003, to Dec 31, 2019, from patients with MCT8 deficiency followed up in 47 hospitals in 22 countries globally. The key inclusion criterion was genetically confirmed MCT8 deficiency. There were no exclusion criteria. Our primary objective was to analyse the overall survival of patients with MCT8 deficiency and document causes of death. We also compared survival between patients who did or did not attain full head control by age 1·5 years and between patients who were or were not underweight by age 1-3 years (defined as a bodyweight-for-age Z score <-2 SDs or <5th percentile according to WHO definition). Other objectives were to assess neurocognitive function and outcomes, and clinical parameters including anthropometric characteristics, biochemical markers, and neuroimaging findings.

Findings: Between Oct 14, 2014, and Jan 17, 2020, we enrolled 151 patients with 73 different MCT8 (SLC16A2) mutations. Median age at diagnosis was 24·0 months (IQR 12·0-60·0, range 0·0-744·0). 32 (21%) of 151 patients died; the main causes of mortality in these patients were pulmonary infection (six [19%]) and sudden death (six [19%]). Median overall survival was 35·0 years (95% CI 8·3-61·7). Individuals who did not attain head control by age 1·5 years had an increased risk of death compared with patients who did attain head control (hazard ratio [HR] 3·46, 95% CI 1·76-8·34; log-rank test p=0·0041). Patients who were underweight during age 1-3 years had an increased risk for death compared with patients who were of normal bodyweight at this age (HR 4·71, 95% CI 1·26-17·58, p=0·021). The few motor and cognitive abilities of patients did not improve with age, as evidenced by the absence of significant correlations between biological age and scores on the Gross Motor Function Measure-88 and Bayley Scales of Infant Development III. Tri-iodothyronine concentrations were above the age-specific upper limit in 96 (95%) of 101 patients and free thyroxine concentrations were below the age-specific lower limit in 94 (89%) of 106 patients. 59 (71%) of 83 patients were underweight. 25 (53%) of 47 patients had elevated systolic blood pressure above the 90th percentile, 34 (76%) of 45 patients had premature atrial contractions, and 20 (31%) of 64 had resting tachycardia. The most consistent MRI finding was a global delay in myelination, which occurred in 13 (100%) of 13 patients.

Interpretation: Our description of characteristics of MCT8 deficiency in a large patient cohort reveals poor survival with a high prevalence of treatable underlying risk factors, and provides knowledge that might inform clinical management and future evaluation of therapies.

Funding: Netherlands Organisation for Health Research and Development, and the Sherman Foundation.
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http://dx.doi.org/10.1016/S2213-8587(20)30153-4DOI Listing
July 2020

Melatonin in neuropaediatric MRI: a retrospective study of efficacy in a general hospital setting.

Eur J Paediatr Neurol 2020 Mar 25;25:172-180. Epub 2019 Oct 25.

University of Groningen, University Medical Centre Groningen, Department of Radiology, Groningen, the Netherlands. Electronic address:

Background: Melatonin may offer a safe and cheap alternative to general anaesthesia and sedatives in neuropaediatric MRI. The purpose of our study was to evaluate its efficacy during a daily scanning programme and to assess its financial benefit.

Methods: Neuro-MRI scans, performed in a general hospital setting after administration of melatonin in 64 children aged 10 months-5 years, were retrospectively reassessed by an experienced paediatric neuroradiologist, rating them as diagnostically contributing or as failed. The financial benefit was calculated.

Results: 49/64 scans (77%) were diagnostically contributing, in 11 (22%) no movement artefact was seen in any sequence; 15/64 scans failed (23%), in 3/15 because of serious movement artefacts, in 12/15 the scan was not started. Repeat scans under general anaesthesia were performed in 17 cases (27%): in the 15 failed cases and in 2 cases initially assessed as failed, but were considered diagnostically contributing in the present study. The financial benefit at the time the scans were made was approximately 13,360 Euro.

Conclusions: In this retrospective study, the use of melatonin in neuropaediatric MRI, made during a daily scanning programme with a remote waiting room, was associated with a high success rate in infants and young children. A minority of scans had no movement artefacts, indicating most children were not asleep. The sleep-inducing effect of melatonin could therefore not be proven, but the high success rate may be attributed to the sedative and/or anxiolytic effect of melatonin. Only a minority of scans had to be repeated under general anesthesia, leading to a reduction of scan related costs.
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http://dx.doi.org/10.1016/j.ejpn.2019.10.001DOI Listing
March 2020

Paediatric motor phenotypes in early-onset ataxia, developmental coordination disorder, and central hypotonia.

Dev Med Child Neurol 2020 01 17;62(1):75-82. Epub 2019 Sep 17.

Department of Pediatrics, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands.

Aims: To investigate the accuracy of phenotypic early-onset ataxia (EOA) recognition among developmental conditions, including developmental coordination disorder (DCD) and hypotonia of central nervous system origin, and the effect of scientifically validated EOA features on changing phenotypic consensus.

Method: We included 32 children (4-17y) diagnosed with EOA (n=11), DCD (n=10), and central hypotonia (n=11). Three paediatric neurologists independently assessed videotaped motor behaviour phenotypically and quantitatively (using the Scale for Assessment and Rating of Ataxia [SARA]). We determined: (1) phenotypic interobserver agreement and phenotypic homogeneity (percentage of phenotypes with full consensus by all three observers according to the underlying diagnosis); (2) SARA (sub)score profiles; and (3) the effect of three scientifically validated EOA features on phenotypic consensus.

Results: Phenotypic homogeneity occurred in 8 out of 11, 2 out of 10, and 1 out of 11 patients with EOA, DCD, and central hypotonia respectively. Homogeneous phenotypic discrimination of EOA from DCD and central hypotonia occurred in 16 out of 21 and 22 out of 22 patients respectively. Inhomogeneously discriminated EOA and DCD phenotypes (5 out of 21) revealed overlapping SARA scores with different SARA subscore profiles. After phenotypic reassessment with scientifically validated EOA features, phenotypic homogeneity changed from 16 to 18 patients.

Interpretation: In contrast to complete distinction between EOA and central hypotonia, the paediatric motor phenotype did not reliably distinguish between EOA and DCD. Reassessment with scientifically validated EOA features could contribute to a higher phenotypic consensus. Early-onset ataxia (EOA) and central hypotonia motor phenotypes were reliably distinguished. EOA and developmental coordination disorder (DCD) motor phenotypes were not reliably distinguished. The EOA and DCD phenotypes have different profiles of the Scale for Assessment and Rating of Ataxia.
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http://dx.doi.org/10.1111/dmcn.14355DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6916203PMC
January 2020

Effectiveness and safety of the tri-iodothyronine analogue Triac in children and adults with MCT8 deficiency: an international, single-arm, open-label, phase 2 trial.

Lancet Diabetes Endocrinol 2019 09 31;7(9):695-706. Epub 2019 Jul 31.

Department of Paediatric Neurology, Addenbrooke's Hospital, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK.

Background: Deficiency of the thyroid hormone transporter monocarboxylate transporter 8 (MCT8) causes severe intellectual and motor disability and high serum tri-iodothyronine (T) concentrations (Allan-Herndon-Dudley syndrome). This chronic thyrotoxicosis leads to progressive deterioration in bodyweight, tachycardia, and muscle wasting, predisposing affected individuals to substantial morbidity and mortality. Treatment that safely alleviates peripheral thyrotoxicosis and reverses cerebral hypothyroidism is not yet available. We aimed to investigate the effects of treatment with the T analogue Triac (3,3',5-tri-iodothyroacetic acid, or tiratricol), in patients with MCT8 deficiency.

Methods: In this investigator-initiated, multicentre, open-label, single-arm, phase 2, pragmatic trial, we investigated the effectiveness and safety of oral Triac in male paediatric and adult patients with MCT8 deficiency in eight countries in Europe and one site in South Africa. Triac was administered in a predefined escalating dose schedule-after the initial dose of once-daily 350 μg Triac, the daily dose was increased progressively in 350 μg increments, with the goal of attaining serum total T concentrations within the target range of 1·4-2·5 nmol/L. We assessed changes in several clinical and biochemical signs of hyperthyroidism between baseline and 12 months of treatment. The prespecified primary endpoint was the change in serum T concentrations from baseline to month 12. The co-primary endpoints were changes in concentrations of serum thyroid-stimulating hormone (TSH), free and total thyroxine (T), and total reverse T from baseline to month 12. These analyses were done in patients who received at least one dose of Triac and had at least one post-baseline evaluation of serum throid function. This trial is registered with ClinicalTrials.gov, number NCT02060474.

Findings: Between Oct 15, 2014, and June 1, 2017, we screened 50 patients, all of whom were eligible. Of these patients, four (8%) patients decided not to participate because of travel commitments. 46 (92%) patients were therefore enrolled in the trial to receive Triac (median age 7·1 years [range 0·8-66·8]). 45 (98%) participants received Triac and had at least one follow-up measurement of thyroid function and thus were included in the analyses of the primary endpoints. Of these 45 patients, five did not complete the trial (two patients withdrew [travel burden, severe pre-existing comorbidity], one was lost to follow-up, one developed of Graves disease, and one died of sepsis). Patients required a mean dose of 38.3 μg/kg of bodyweight (range 6·4-84·3) to attain T concentrations within the target range. Serum T concentration decreased from 4·97 nmol/L (SD 1·55) at baseline to 1·82 nmol/L (0·69) at month 12 (mean decrease 3·15 nmol/L, 95% CI 2·68-3·62; p<0·0001), while serum TSH concentrations decreased from 2·91 mU/L (SD 1·68) to 1·02 mU/L (1·14; mean decrease 1·89 mU/L, 1·39-2·39; p<0·0001) and serum free T concentrations decreased from 9·5 pmol/L (SD 2·5) to 3·4 (1·6; mean decrease 6·1 pmol/L (5·4-6·8; p<0·0001). Additionally, serum total T concentrations decreased by 31·6 nmol/L (28·0-35·2; p<0·0001) and reverse T by 0·08 nmol/L (0·05-0·10; p<0·0001). Seven treatment-related adverse events (transiently increased perspiration or irritability) occurred in six (13%) patients. 26 serious adverse events that were considered unrelated to treatment occurred in 18 (39%) patients (mostly hospital admissions because of infections). One patient died from pulmonary sepsis leading to multi-organ failure, which was unrelated to Triac treatment.

Interpretation: Key features of peripheral thyrotoxicosis were alleviated in paediatric and adult patients with MCT8 deficiency who were treated with Triac. Triac seems a reasonable treatment strategy to ameliorate the consequences of untreated peripheral thyrotoxicosis in patients with MCT8 deficiency.

Funding: Dutch Scientific Organization, Sherman Foundation, NeMO Foundation, Wellcome Trust, UK National Institute for Health Research Cambridge Biomedical Centre, Toulouse University Hospital, and Una Vita Rara ONLUS.
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http://dx.doi.org/10.1016/S2213-8587(19)30155-XDOI Listing
September 2019

The neurological phenotype of developmental motor patterns during early childhood.

Brain Behav 2019 01 28;9(1):e01153. Epub 2018 Nov 28.

Department of Pediatrics, Beatrix Children's Hospital, University Medical Center Groningen, Groningen, The Netherlands.

Introduction: During early childhood, typical human motor behavior reveals a gradual transition from automatic motor patterns to acquired motor skills, by the continuous interplay between nature and nurture. During the wiring and shaping of the underlying motor networks, insight into the neurological phenotype of developmental motor patterns is incomplete. In healthy, typically developing children (0-3 years of age), we therefore aimed to investigate the neurological phenotype of developmental motor patterns.

Methods: In 32 healthy, typically developing children (0-3 years), we video-recorded spontaneous motor behavior, general movements (GMs), and standardized motor tasks. We classified the motor patterns by: (a) the traditional neurodevelopmental approach, by Gestalt perception and (b) the classical neurological approach, by the clinical phenotypic determination of movement disorder features. We associated outcomes by Cramer's V.

Results: Developmental motor patterns revealed (a) choreatic-like features (≤3 months; associated with fidgety GMs (r = 0.732) and startles (r = 0.687)), (b) myoclonic-like features (≤3 months; associated with fidgety GMs (r = 0.878) and startles (r = 0.808)), (c) dystonic-like features (0-3 years; associated with asymmetrical tonic neck reflex (r = 0.641) and voluntary movements (r = 0.517)), and (d) ataxic-like features (>3 months; associated with voluntary movements (r = 0.928)).

Conclusions: In healthy infants and toddlers (0-3 years), typical developmental motor patterns reveal choreatic-, myoclonic-, dystonic- and ataxic-like features. The transient character of these neurological phenotypes is placed in perspective of the physiological shaping of the underlying motor centers. Neurological phenotypic insight into developmental motor patterns can contribute to adequate discrimination between ontogenetic and initiating pathological movement features and to adequate interpretation of therapeutic interactions.
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http://dx.doi.org/10.1002/brb3.1153DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6346655PMC
January 2019

A Recurrent De Novo PACS2 Heterozygous Missense Variant Causes Neonatal-Onset Developmental Epileptic Encephalopathy, Facial Dysmorphism, and Cerebellar Dysgenesis.

Am J Hum Genet 2018 05 12;102(5):995-1007. Epub 2018 Apr 12.

University of Groningen, University Medical Center Groningen, Department of Genetics, 9700 RB Groningen, the Netherlands.

Developmental and epileptic encephalopathies (DEEs) represent a large clinical and genetic heterogeneous group of neurodevelopmental diseases. The identification of pathogenic genetic variants in DEEs remains crucial for deciphering this complex group and for accurately caring for affected individuals (clinical diagnosis, genetic counseling, impacting medical, precision therapy, clinical trials, etc.). Whole-exome sequencing and intensive data sharing identified a recurrent de novo PACS2 heterozygous missense variant in 14 unrelated individuals. Their phenotype was characterized by epilepsy, global developmental delay with or without autism, common cerebellar dysgenesis, and facial dysmorphism. Mixed focal and generalized epilepsy occurred in the neonatal period, controlled with difficulty in the first year, but many improved in early childhood. PACS2 is an important PACS1 paralog and encodes a multifunctional sorting protein involved in nuclear gene expression and pathway traffic regulation. Both proteins harbor cargo(furin)-binding regions (FBRs) that bind cargo proteins, sorting adaptors, and cellular kinase. Compared to the defined PACS1 recurrent variant series, individuals with PACS2 variant have more consistently neonatal/early-infantile-onset epilepsy that can be challenging to control. Cerebellar abnormalities may be similar but PACS2 individuals exhibit a pattern of clear dysgenesis ranging from mild to severe. Functional studies demonstrated that the PACS2 recurrent variant reduces the ability of the predicted autoregulatory domain to modulate the interaction between the PACS2 FBR and client proteins, which may disturb cellular function. These findings support the causality of this recurrent de novo PACS2 heterozygous missense in DEEs with facial dysmorphim and cerebellar dysgenesis.
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http://dx.doi.org/10.1016/j.ajhg.2018.03.005DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5986694PMC
May 2018

Construct Validity and Reliability of the SARA Gait and Posture Sub-scale in Early Onset Ataxia.

Front Hum Neurosci 2017 13;11:605. Epub 2017 Dec 13.

Departments of Pediatrics and Neurology, Beatrix Children's Hospital, University Medical Center Groningen, Groningen, Netherlands.

In children, gait and posture assessment provides a crucial marker for the early characterization, surveillance and treatment evaluation of early onset ataxia (EOA). For reliable data entry of studies targeting at gait and posture improvement, uniform quantitative biomarkers are necessary. Until now, the pediatric test construct of gait and posture scores of the Scale for Assessment and Rating of Ataxia sub-scale (SARA) is still unclear. In the present study, we aimed to validate the construct validity and reliability of the pediatric (SARA) sub-scale. We included 28 EOA patients [15.5 (6-34) years; median (range)]. For inter-observer reliability, we determined the ICC on EOA SARA sub-scores by three independent pediatric neurologists. For convergent validity, we associated SARA sub-scores with: (1) Ataxic gait Severity Measurement by Klockgether (ASMK; dynamic balance), (2) Pediatric Balance Scale (PBS; static balance), (3) Gross Motor Function Classification Scale -extended and revised version (GMFCS-E&R), (4) SARA-kinetic scores (SARA; kinetic function of the upper lower limbs), (5) Archimedes Spiral (AS; kinetic function of the upper limbs), and (6) total SARA scores (SARA; i.e., summed SARA, SARA, and SARA sub-scores). For discriminant validity, we investigated whether EOA co-morbidity factors (myopathy and myoclonus) could influence SARA sub-scores. The inter-observer agreement (ICC) on EOA SARA sub-scores was high (0.97). SARA was strongly correlated with the other ataxia and functional scales [ASMK ( = -0.819; < 0.001); PBS ( = -0.943; < 0.001); GMFCS-E&R ( = -0.862; < 0.001); SARA ( = 0.726; < 0.001); AS ( = 0.609; = 0.002); and SARA ( = 0.935; < 0.001)]. Comorbid myopathy influenced SARA scores by concurrent muscle weakness, whereas comorbid myoclonus predominantly influenced SARA scores. In young EOA patients, separate SARA parameters reveal a good inter-observer agreement and convergent validity, implicating the reliability of the scale. In perspective of incomplete discriminant validity, it is advisable to interpret SARA scores for comorbid muscle weakness.
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http://dx.doi.org/10.3389/fnhum.2017.00605DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5733344PMC
December 2017

Molybdenum cofactor deficiency type A: Prenatal monitoring using MRI.

Eur J Paediatr Neurol 2018 May 28;22(3):536-540. Epub 2017 Nov 28.

Section of Metabolic Diseases, Beatrix Children's Hospital, University Medical Center Groningen, University of Groningen, PO Box 30.001, 9700 RB Groningen, the Netherlands. Electronic address:

Molybdenum cofactor deficiency type A (MoCD-A) is an inborn error of metabolism presenting early after birth with severe seizures. Recently, experimental substitution treatment with cyclic pyranopterin monophosphate (cPMP) has become available. Because prenatal data is scarce, we report data of prenatal Magnetic Resonance Imaging (MRI) in two cases with MoCD-A demonstrating signs of possible early brain injury. Prenatal MRI can be used for monitoring in MoCD-A to guide decision-making in timing of delivery.
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http://dx.doi.org/10.1016/j.ejpn.2017.11.006DOI Listing
May 2018

Heterogeneous clinical spectrum of DNAJC12-deficient hyperphenylalaninemia: from attention deficit to severe dystonia and intellectual disability.

J Med Genet 2017 Aug 9. Epub 2017 Aug 9.

Division of Metabolism, University Children's Hospital Zurich, Zurich, Switzerland.

Background: Autosomal recessive mutations in , encoding a cochaperone of HSP70 with hitherto unknown function, were recently described to lead to hyperphenylalaninemia, central monoamine neurotransmitter (dopamine and serotonin) deficiency, dystonia and intellectual disability in six subjects affected by homozygous variants.

Objective: Patients exhibiting hyperphenylalaninemia in whom deficiencies in hepatic phenylalanine hydroxylase and tetrahydrobiopterin cofactor metabolism had been excluded were subsequently analysed for variants.

Methods: To analyse DNAJC12, genomic DNA from peripheral blood (Sanger sequencing), as well as quantitative messenger RNA (Real Time Quantitative Polymerase Chain Reaction (RT-qPCR)) and protein expression (Western blot) from primary skin fibroblasts were performed.

Results: We describe five additional patients from three unrelated families with homozygosity/compound heterozygosity in with three novel variants: c.85delC/p.Gln29Lysfs*38, c.596G>T/p.*199Leuext*42 and c.214C>T/p.(Arg72*). In contrast to previously reported DNAJC12-deficient patients, all five cases showed a very mild neurological phenotype. In two subjects, cerebrospinal fluid and primary skin fibroblasts were analysed showing similarly low 5-hydroxyindolacetic acid and homovanillic acid concentrations but more reduced expressions of mRNA and DNAJC12 compared with previously described patients. All patients responded to tetrahydrobiopterin challenge by lowering blood phenylalanine levels.

Conclusions: DNAJC12 deficiency appears to result in a more heterogeneous neurological phenotype than originally described. While early identification and institution of treatment with tetrahydrobiopterin and neurotransmitter precursors is crucial to ensure optimal neurological outcome in DNAJC12-deficient patients with a severe phenotype, optimal treatment for patients with a milder phenotype remains to be defined.
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http://dx.doi.org/10.1136/jmedgenet-2017-104875DOI Listing
August 2017

Reliability and discriminant validity of ataxia rating scales in early onset ataxia.

Dev Med Child Neurol 2017 04 21;59(4):427-432. Epub 2016 Oct 21.

Department of Pediatrics, Beatrix Children's Hospital, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands.

Aim: To determine whether ataxia rating scales are reliable disease biomarkers for early onset ataxia (EOA).

Method: In 40 patients clinically identified with EOA (28 males, 12 females; mean age 15y 3mo [range 5-34y]), we determined interobserver and intraobserver agreement (interclass correlation coefficient [ICC]) and discriminant validity of ataxia rating scales (International Cooperative Ataxia Rating Scale [ICARS], Scale for Assessment and Rating of Ataxia [SARA], and Brief Ataxia Rating Scale [BARS]). Three paediatric neurologists independently scored ICARS, SARA and BARS performances recorded on video, and also phenotyped the primary and secondary movement disorder features. When ataxia was the primary movement disorder feature, we assigned patients to the subgroup 'EOA with core ataxia' (n=26). When ataxia concurred with other prevailing movement disorders (such as dystonia, myoclonus, and chorea), we assigned patients to the subgroup 'EOA with comorbid ataxia' (n=12).

Results: ICC values were similar in both EOA subgroups of 'core' and 'comorbid' ataxia (0.92-0.99; ICARS, SARA, and BARS). Independent of the phenotype, the severity of the prevailing movement disorder predicted the ataxia rating scale scores (β=0.83-0.88; p<0.05).

Interpretation: In patients with EOA, the reliability of ataxia rating scales is high. However, the discriminative validity for 'ataxia' is low. For adequate interpretation of ataxia rating scale scores, application in uniform movement disorder phenotypes is essential.
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http://dx.doi.org/10.1111/dmcn.13291DOI Listing
April 2017

Diagnostic value of MRS-quantified brain tissue lactate level in identifying children with mitochondrial disorders.

Eur Radiol 2017 Mar 7;27(3):976-984. Epub 2016 Jun 7.

Department of Radiology, University Medical Centre Groningen, University of Groningen, Hanzeplein 1, 9713 GZ, Groningen, The Netherlands.

Objectives: Magnetic resonance spectroscopy (MRS) of children with or without neurometabolic disease is used for the first time for quantitative assessment of brain tissue lactate signals, to elaborate on previous suggestions of MRS-detected lactate as a marker of mitochondrial disease.

Methods: Multivoxel MRS of a transverse plane of brain tissue cranial to the ventricles was performed in 88 children suspected of having neurometabolic disease, divided into 'definite' (n = 17, ≥1 major criteria), 'probable' (n = 10, ≥2 minor criteria), 'possible' (n = 17, 1 minor criterion) and 'unlikely' mitochondrial disease (n = 44, none of the criteria). Lactate levels, expressed in standardized arbitrary units or relative to creatine, were derived from summed signals from all voxels. Ten 'unlikely' children with a normal neurological exam served as the MRS reference subgroup. For 61 of 88 children, CSF lactate values were obtained.

Results: MRS lactate level (>12 arbitrary units) and the lactate-to-creatine ratio (L/Cr >0.22) differed significantly between the definite and the unlikely group (p = 0.015 and p = 0.001, respectively). MRS L/Cr also differentiated between the probable and the MRS reference subgroup (p = 0.03). No significant group differences were found for CSF lactate.

Conclusion: MRS-quantified brain tissue lactate levels can serve as diagnostic marker for identifying mitochondrial disease in children.

Key Points: • MRS-detected brain tissue lactate levels can be quantified. • MRS lactate and lactate/Cr are increased in children with mitochondrial disease. • CSF lactate is less suitable as marker of mitochondrial disease.
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http://dx.doi.org/10.1007/s00330-016-4454-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5306328PMC
March 2017

The Burke-Fahn-Marsden Dystonia Rating Scale is Age-Dependent in Healthy Children.

Mov Disord Clin Pract 2016 Nov-Dec;3(6):580-586. Epub 2016 May 3.

Department of Pediatrics Beatrix Children's Hospital University Medical Center Groningen, University of Groningen Groningen The Netherlands.

Background: The Burke-Fahn-Marsden Dystonia Rating Scale is a universally applied instrument for the quantitative assessment of dystonia in both children and adults. However, immature movements by healthy young children may also show "dystonic characteristics" as a consequence of physiologically incomplete brain maturation. This could implicate that Burke-Fahn-Marsden scale scores are confounded by pediatric age.

Objective: In healthy young children, we aimed to determine whether physiologically immature movements and postures can induce an age-related effect on Burke-Fahn-Marsden movement and disability scale scores.

Methods: Nine assessors specializied in movement disorders (3 adult neurologists, 3 pediatric neurologists, and 3 MD/PhD students) independently scored the Burke-Fahn-Marsden movement scale in 52 healthy children (4-16 years of age; 2 boys and 2 girls per year of age). Independent of that, parents scored their children's functional motor development according to the Burke-Fahn-Marsden disability scale in another 52 healthy children (4-16 years of age; 2 boys and 2 girls per year of age). By regression analysis, we determined the association between Burke-Fahn-Marsden movement and disability scales outcomes and pediatric age.

Results: In healthy children, assessment of physiologically immature motor performances by the Burke-Fahn-Marsden movement and disability scales showed an association between the outcomes of both scales and age (until 16 years and 12 years of age, β = -0.72 and β = -0.60, for Burke-Fahn-Marsden movement and disability scale, respectively [both < 0.001]).

Conclusions: The Burke-Fahn-Marsden movement and disability scales are influenced by the age of the child. For accurate interpretation of longitudinal Burke-Fahn-Marsden Dystonia Rating Scale scores in young dystonic children, consideration of pediatric age-relatedness appears advisory.
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http://dx.doi.org/10.1002/mdc3.12339DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6353340PMC
May 2016

Reliability of phenotypic early-onset ataxia assessment: a pilot study.

Dev Med Child Neurol 2016 Jan 21;58(1):70-6. Epub 2015 May 21.

Paediatrics, Beatrix Children's Hospital, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands.

Aim: To investigate the interobserver agreement on phenotypic early-onset ataxia (EOA) assessment and to explore whether the Scale for Assessment and Rating of Ataxia (SARA) could provide a supportive marker.

Method: Seven movement disorder specialists provided independent phenotypic assessments of potentially ataxic motor behaviour in 40 patients (mean age 15y [range 5-34]; data derived from University Medical Center Groningen medical records 1998-2012). We determined interobserver agreement by Fleiss' kappa. Furthermore, we compared percentage SARA subscores ([subscore/total score]×100%) between 'indisputable' (primary ataxia recognition by at least six observers) and 'mixed' (ataxia recognition, unfulfilling 'indisputable' criteria) EOA phenotypes.

Results: Agreement on phenotypic EOA assessment was statistically significant (p<0.001), but of moderate strength (Fleiss' kappa=0.45; 95% CI 0.38-0.51). During mild disease progression, percentage SARA gait subscores discriminated between 'indisputable' and 'mixed' EOA phenotypes. In patients with percentage SARA gait subscores >30%, primary ataxia was more frequently present than in those with subscores <30% (p=0.001).

Interpretation: Among movement-disorder professionals from different disciplines, interobserver agreement on phenotypic EOA recognition is of limited strength. SARA gait subscores can provide a supportive discriminative marker between EOA phenotypes. Hopefully, future phenotypic insight will contribute to the inclusion of uniform, high-quality data in international EOA databases.
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http://dx.doi.org/10.1111/dmcn.12804DOI Listing
January 2016

Subtle bilirubin-induced neurodevelopmental dysfunction (BIND) in the term and late preterm infant: does it exist?

Semin Perinatol 2014 Nov 1;38(7):465-71. Epub 2014 Oct 1.

Department of Neurology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, Groningen 9713 GZ, The Netherlands. Electronic address:

Subtle bilirubin-induced neurological dysfunction (BIND) is defined as disturbances in sensory and sensorimotor integration, central auditory processing, coordination, and muscle tone in the absence of the classical findings of kernicterus. This review is restricted to the (sensori)motor signs of BIND associated with unconjugated hyperbilirubinemia in term and late preterm neonates. The diagnosis of BIND at follow-up requires validated, age-specific techniques that are designed to identify these disturbances in infancy and later childhood. The (sensori)motor signs of BIND are compatible with the pathological substrate of unconjugated hyperbilirubinemia and its known effects on the brain.
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http://dx.doi.org/10.1053/j.semperi.2014.08.009DOI Listing
November 2014

Infants with Tyrosinemia Type 1: Should phenylalanine be supplemented?

JIMD Rep 2015 26;18:117-24. Epub 2014 Sep 26.

Beatrix Children's Hospital, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.

Tyrosinemia type 1 (HT1) is an inborn error of tyrosine catabolism caused by fumarylacetoacetase deficiency. Biochemically, this results in accumulation of toxic metabolites including succinylacetone. Clinically, HT1 is characterized by severe liver, kidney, and neurological problems. Treatment with NTBC and dietary restriction of tyrosine and phenylalanine have strongly improved outcome, but impaired neurocognitive development has been reported. Whether impaired neurocognitive outcome results from high blood tyrosine or low blood phenylalanine concentrations is currently unknown. In this report, two HT1 newborns, diagnosed by neonatal screening, are presented. The first patient showed low phenylalanine concentrations, growth retardation, neurological impairments, and skin problems, clearly improving after institution of phenylalanine supplementation (~30 mg/kg/day) at age 6 months, while both blood phenylalanine and tyrosine concentrations increased. In the second patient, phenylalanine supplementation (~20 mg/kg/day) was initiated as soon as low phenylalanine concentrations were observed at age 19 days. On this regimen, blood phenylalanine concentrations increased, and hypophenylalaninemia was less frequently observed than in the first patient, whereas blood tyrosine concentrations tended to increase. Clinically, no growth, neurological, or skin problems have been observed. The combination of knowledge obtained from these cases suggests that hypophenylalaninemia rather than hypertyrosinemia during the first months of life may impair neurocognitive development in young HT1 infants. Phenylalanine supplementation should really be considered in HT1 patients with consistently low blood phenylalanine concentrations during the first months of life. However, the minimal phenylalanine concentrations acceptable and the optimal phenylalanine supplementation regimen require further investigation.
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http://dx.doi.org/10.1007/8904_2014_358DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4361924PMC
March 2015

Assessment of speech in early-onset ataxia: a pilot study.

Dev Med Child Neurol 2014 Dec 18;56(12):1202-1206. Epub 2014 Jun 18.

Department of Paediatrics, Beatrix Children's Hospital, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands.

Aim: The aim of the study was to determine whether paediatric ataxia speech subscores are reliably applicable for international early-onset ataxia (EOA) databases. If so, we reasoned that ataxia speech subscores should be associated with ataxia scores and involve high interobserver agreement, including those for internationally applicable Scale for Assessment and Rating of Ataxia (SARA) syllable repetition tasks (SARASRT).

Method: Three independent paediatric neurologists and a speech therapist scored speech in 52 healthy children (mean age 10y, range 4-16y) and 40 individuals with EOA (mean age 15y, range 5-34y). We compared ataxia speech subscores for the association with age and ataxia scores as well as interobserver reliability.

Results: In healthy children, ataxia speech subscores were moderately associated with age (International Cooperative Ataxia Rating Scale [ICARS]: r=-0.515; SARA: r=-0.321; p<0.05) and with ataxia scores (ICARS: r=0.552; SARA: r=0.336; p<0.05), and revealed slight to moderate interobserver agreement (ICARS-intraclass correlation coefficient [ICC]: 0.380; SARA-ICC: 0.185; SARASRT-ICC: 0.509). In EOA, speech subscores have a strong association with ataxia scores (ICARS: r=0.735; SARA: r=0.730; p<0.001) and revealed substantial to nearly perfect interobserver agreement (ICARS-ICC: 0.812; SARA-ICC: 0.854; SARASRT-ICC: 0.724).

Interpretation: Early-onset ataxia speech subscores are associated with ataxia and also reveal high interobserver agreement, including those internationally applicable to SARASRT. We conclude that SARASRT appears to be applicable for EOA databases. However, before syllable repetition tasks are included, we would advise to wait for the results published by the international Childhood Ataxia and Cerebellar Group.
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http://dx.doi.org/10.1111/dmcn.12517DOI Listing
December 2014

Neonatal seizures: aetiology by means of a standardized work-up.

Eur J Paediatr Neurol 2014 May 17;18(3):360-7. Epub 2014 Feb 17.

Department of Child Neurology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9713 EZ Groningen, The Netherlands. Electronic address:

Unlabelled: Neonatal seizures are an alarming symptom and are frequent in neonates. It is important to find the cause of neonatal seizures to start a specific treatment and to give a meaningful prognosis. The aim of this study is to investigate the incidence of different aetiologies of neonatal seizures in our hospital by a specific work-up.

Methods: All full-term born neonates from January 2002 till September 2009 with neonatal seizures, admitted to our neonatal intensive care unit were included (n = 221). Aetiology was investigated by means of a standardized aetiologic work-up.

Results: The frequencies of aetiologies of neonatal seizures were: hypoxic-ischemic encephalopathy (HIE) (n = 119; 53.9%), metabolic or electrolyte disorders (n = 24; 10.9%), intracranial hemorrhage (n = 20; 9.0%), ischemic infarction (n = 16; 7.2%), intracranial infections (n = 14; 6.3%), congenital malformations of the central nervous system (n = 7; 3.2%), inborn errors of metabolism (n = 5; 2.3%), epileptic syndromes (n = 1; 0.5%), HIE + hypoglycemia (n = 4; 1.8%), HIE + intracranial hemorrhage (n = 3; 1.4%), HIE + ischemic infarction (n = 1; 0.5%), ischemic infarction + intracranial hemorrhage (n = 1; 0.5%), idiopathic (n = 4, 1.8%), intoxications (n = 1; 0.5%) and unknown (n = 1; 0.5%).

Conclusion: Our work-up is a practical tool to find the aetiology of neonatal seizures.
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http://dx.doi.org/10.1016/j.ejpn.2014.01.014DOI Listing
May 2014

NUBPL mutations in patients with complex I deficiency and a distinct MRI pattern.

Neurology 2013 Apr 3;80(17):1577-83. Epub 2013 Apr 3.

Department of Child Neurology, VU University Medical Center, Amsterdam, the Netherlands.

Objective: To identify the mutated gene in a group of patients with an unclassified heritable white matter disorder sharing the same, distinct MRI pattern.

Methods: We used MRI pattern recognition analysis to select a group of patients with a similar, characteristic MRI pattern. We performed whole-exome sequencing to identify the mutated gene. We examined patients' fibroblasts for biochemical consequences of the mutant protein.

Results: We identified 6 patients from 5 unrelated families with a similar MRI pattern showing predominant abnormalities of the cerebellar cortex, deep cerebral white matter, and corpus callosum. The 4 tested patients had a respiratory chain complex І deficiency. Exome sequencing revealed mutations in NUBPL, encoding an iron-sulfur cluster assembly factor for complex І, in all patients. Upon identification of the mutated gene, we analyzed the MRI of a previously published case with NUBPL mutations and found exactly the same pattern. A strongly decreased amount of NUBPL protein and fully assembled complex I was found in patients' fibroblasts. Analysis of the effect of mutated NUBPL on the assembly of the peripheral arm of complex I indicated that NUBPL is involved in assembly of iron-sulfur clusters early in the complex I assembly pathway.

Conclusion: Our data show that NUBPL mutations are associated with a unique, consistent, and recognizable MRI pattern, which facilitates fast diagnosis and obviates the need for other tests, including assessment of mitochondrial complex activities in muscle or fibroblasts.
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http://dx.doi.org/10.1212/WNL.0b013e31828f1914DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3662327PMC
April 2013

Neurodevelopment after moderate hyperbilirubinemia at term.

Pediatr Res 2013 May 13;73(5):655-60. Epub 2013 Feb 13.

Department of Neurology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.

Background: The aim of this work was to investigate in a prospective study whether moderate hyperbilirubinemia in healthy term neonates is associated with an increase of minor neurological dysfunction (MND) and behavioral problems up to 18 mo.

Method: We enrolled 43 healthy term infants with a bilirubin level ≥ 220 µmol/l (BILI group) at 72-96 h postnatally at the University Medical Center Groningen (UMCG), including eight referrals for hyperbilirubinemia. Seventy healthy term infants born at the UMCG with bilirubin level <220 µmol/l served as comparisons (COMP group). We evaluated the neurologic condition neonatally and at 3 and 18 mo; behavior was evaluated at birth and 18 mo.

Results: Rates of MND in BILI and COMP groups were similar at all ages. However, bilirubin levels of ≥ 300 µmol/l (n = 10) were associated with an increased risk of complex MND (odds ratio: 4.21; 95% confidence interval: 1.02-17.37). Neonatally, BILI infants were more often lethargic than COMP infants (odds ratio: 3.54; 95% confidence interval: 1.32-9.51); at 18 mo, they had higher hyperactivity scores (effect: 0.32; 95% confidence interval: 0.08-0.56).

Conclusion: Occurrence of complex MND at 18 mo in infants with moderate hyperbilirubinemia was not different from that in comparison infants, but bilirubin level ≥ 300 was associated with an increased risk of complex MND. This study also suggests that minor behavioral effects of moderate hyperbilirubinemia cannot be excluded.
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http://dx.doi.org/10.1038/pr.2013.28DOI Listing
May 2013

Favorable outcome in a newborn with molybdenum cofactor type A deficiency treated with cPMP.

Pediatrics 2012 Oct 17;130(4):e1005-10. Epub 2012 Sep 17.

Division of Metabolic Diseases, Department of Pediatrics, Beatrix Children's Hospital, University Medical Center Groningen, University of Groningen, Groningen, Netherlands.

Molybdenum cofactor deficiency (MoCD) is a lethal autosomal recessive inborn error of metabolism with devastating neurologic manifestations. Currently, experimental treatment with cyclic pyranopterin monophosphate (cPMP) is available for patients with MoCD type A caused by a mutation in the MOCS-1 gene. Here we report the first case of an infant, prenatally diagnosed with MoCD type A, whom we started on treatment with cPMP 4 hours after birth. The most reliable method to evaluate neurologic functioning in early infancy is to assess the quality of general movements (GMs) and fidgety movements (FMs). After a brief period of seizures and cramped-synchronized GMs on the first day, our patient showed no further clinical signs of neurologic deterioration. Her quality of GMs was normal by the end of the first week. Rapid improvement of GM quality together with normal FMs at 3 months is highly predictive of normal neurologic outcome. We demonstrated that a daily cPMP dose of even 80 μg/kg in the first 12 days reduced the effects of neurodegenerative damage even when seizures and cramped-synchronized GMs were already present. We strongly recommend starting cPMP treatment as soon as possible after birth in infants diagnosed with MoCD type A.
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http://dx.doi.org/10.1542/peds.2011-3330DOI Listing
October 2012

Novel pathogenic mechanism suggested by ex vivo analysis of MCT8 (SLC16A2) mutations.

Hum Mutat 2009 Jan;30(1):29-38

Department of Internal Medicine, Erasmus University Medical Center, Rotterdam, The Netherlands.

Monocarboxylate transporter 8 (MCT8; approved symbol SLC16A2) facilitates cellular uptake and efflux of 3,3',5-triiodothyronine (T3). Mutations in MCT8 are associated with severe psychomotor retardation, high serum T3 and low 3,3',5'-triiodothyronine (rT3) levels. Here we report three novel MCT8 mutations. Two subjects with the F501del mutation have mild psychomotor retardation with slightly elevated T3 and normal rT3 levels. T3 uptake was mildly affected in F501del fibroblasts and strongly decreased in fibroblasts from other MCT8 patients, while T3 efflux was always strongly reduced. Moreover, type 3 deiodinase activity was highly elevated in F501del fibroblasts, whereas it was reduced in fibroblasts from other MCT8 patients, probably reflecting parallel variation in cellular T3 content. Additionally, T3-responsive genes were markedly upregulated by T3 treatment in F501del fibroblasts but not in fibroblasts with other MCT8 mutations. In conclusion, mutations in MCT8 result in a decreased T3 uptake in skin fibroblasts. The much milder clinical phenotype of patients with the F501del mutation may be correlated with the relatively small decrease in T3 uptake combined with an even greater decrease in T3 efflux. If fibroblasts are representative of central neurons, abnormal brain development associated with MCT8 mutations may be the consequence of either decreased or increased intracellular T3 concentrations.
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http://dx.doi.org/10.1002/humu.20808DOI Listing
January 2009

Magnetic resonance imaging and proton magnetic resonance spectroscopy of the brain in the diagnostic evaluation of developmental delay.

Eur J Paediatr Neurol 2009 Mar 24;13(2):181-90. Epub 2008 Jun 24.

Beatrix Children's Hospital, University Medical Centre Groningen, University of Groningen, Groningen, The Netherlands.

Aim: To assess the contribution of MRI and proton spectroscopy (1HMRS) in establishing an etiological diagnosis in children with developmental delay (DD) and to assess whether the chance of finding specific abnormalities correlates with the presence of neurological signs and/or abnormal head circumference (HC).

Methods: Patients were derived from a cohort of 325 consecutive patients with DD receiving structured multidisciplinary evaluation in our centre. Patients had MRI/1HMRS if a diagnosis could not be made clinically and if additional neurological signs and/or abnormal HC and/or an IQ below 50 were present. The MRI protocol consisted of axial IR, T2, FLAIR, sagittal T1 and coronal T2 sequences. Multivoxel 1HMRS was located in a plane superior to the lateral ventricles with voxels in both grey matter and white matter.

Results: One hundred and nine children were scanned, 80 of them because of neurological signs and/or abnormal HC. Although minor abnormalities were noted in the vast majority of patients, MRI and/or 1HMRS really contributed to an etiological diagnosis in only 10 (9%) patients, all of whom were scanned because of neurological signs. In these 10 patients, 1HMRS was diagnostic in one patient and of additional value to MRI findings in 3 patients.

Conclusions: MRI and 1HMRS may contribute to the diagnostic evaluation of DD, especially if applied specifically to patients with neurological signs, whereas its role is very limited in children without these signs.
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http://dx.doi.org/10.1016/j.ejpn.2008.04.014DOI Listing
March 2009

Quantitative multivoxel 1H MR spectroscopy of the brain in children with acute liver failure.

Eur Radiol 2008 Nov 21;18(11):2601-9. Epub 2008 May 21.

Department of Radiology, Beatrix Children's Hospital, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.

Acute liver failure (ALF)-related encephalopathy was previously characterized by MR spectroscopy of single voxels containing both grey and white matter brain tissue. Quantitative multivoxel MRS was used here to compare grey and white matter brain tissue concentrations of glutamate/glutamine (Glx) and lactate in ALF and associate the results with other liver function parameters. Five pediatric patients with ALF-related encephalopathy and five controls, examined after successful liver transplantation, were examined by brain MRI/MRS. ALF patients had higher Glx and lactate concentrations in brain white matter than controls (Glx + 125%: P < 0.01; lactate + 33%, P < 0.05) and higher Glx in grey matter (Glx + 125%: P < 0.01). Within the group of ALF patients positive correlations were found between grey or white matter lactate concentration and serum ammonia (P < 0.05), and negative correlations between grey or white matter Glx and venous pH (P < 0.001). This is the first study presenting evidence of high Glx levels in both white and grey matter brain tissue in ALF-related encephalopathy. The elevations in CNS Glx and lactate concentrations appear to relate to hepatic detoxification (ammonia, venous pH), rather than to liver parenchymal integrity (aspartate aminotransferase, alanine aminotransferase) or biliary cholestasis (bilirubin, gamma-glutamyl transpeptidase, alkaline phosphatase).
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http://dx.doi.org/10.1007/s00330-008-1049-zDOI Listing
November 2008

1H magnetic resonance spectroscopy in monocarboxylate transporter 8 gene deficiency.

J Clin Endocrinol Metab 2008 May 4;93(5):1854-9. Epub 2008 Mar 4.

Department of Radiology, University Medical Center Groningen and University of Groningen, Hanzeplein 1, Groningen, The Netherlands.

Context: In monocarboxylate transporter 8 (MCT8) gene deficiency, a syndrome combining thyroid and neurological abnormalities, the central nervous system has not yet been characterized by magnetic resonance (MR) spectroscopy.

Objective: We studied whether the degree of dysmyelinization in MCT8 gene deficiency according to MR imaging (MRI) is coupled with abnormalities in brain metabolism.

Design: MRI and MR spectroscopy of the brain were performed twice in two MCT8 gene deficiency patients, for the first time at age 8-10 months and for the second time at age 17-28 months. The results were compared with those obtained in controls of a similar age.

Results: Compared with controls, young children with MCT8 show choline and myoinositol level increases and N-acetyl aspartate decreases in supraventricular gray and white matter, phenomena associated with the degree of dysmyelinization according to MRI.

Conclusion: MCT8 gene deficiency results in deviant myelinization and general atrophy, which is substantiated by the MR spectroscopy findings of increased choline and myoinositol levels and decreased N-acetyl aspartate. The observations suggest that different mutations in the MCT8 gene lead to differences in the severity of the clinical spectrum, dysmyelinization, and MR spectroscopy-detectable changes in brain metabolism.
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http://dx.doi.org/10.1210/jc.2007-2441DOI Listing
May 2008

Successful treatment of a guanidinoacetate methyltransferase deficient patient: findings with relevance to treatment strategy and pathophysiology.

Mol Genet Metab 2007 Jul 26;91(3):294-6. Epub 2007 Apr 26.

Beatrix Children's Hospital, University Medical Centre Groningen, University of Groningen, The Netherlands.

Biochemical and developmental results of treatment of a guanidinoacetate methyltransferase (GAMT) deficient patient with a mild clinical presentation and remarkable developmental improvement after treatment are presented. Treatment with creatine (Cr) supplementation resulted in partial normalization of cerebral (measured with magnetic resonance proton spectroscopy) and plasma levels of Cr and guanidinoacetate (GAA). Addition of high dose ornithine to the treatment led to further normalization of plasma GAA, while cerebral Cr and GAA did not improve further.
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http://dx.doi.org/10.1016/j.ymgme.2007.03.006DOI Listing
July 2007