L-serine treatment in patients with GRIN-related encephalopathy: a phase 2A, non-randomized study.

GRIN-related disorders are rare developmental encephalopathies with variable manifestations and limited therapeutic options. Here, we present the first non-randomized, open-label, single-arm trial (NCT04646447) designed to evaluate the tolerability and efficacy of L-serine in children with GRIN genetic variants leading to loss-of-function. In this phase 2A trial, patients aged 2-18 years with GRIN loss-of-function pathogenic variants received L-serine for 52 weeks. Primary end points included safety and efficacy by measuring changes in the Vineland Adaptive Behavior Scales, Bayley Scales, age-appropriate Wechsler Scales, Gross Motor Function-88, Sleep Disturbance Scale for Children, Pediatric Quality of Life Inventory, Child Behavior Checklist and the Caregiver-Teacher Report Form following 12 months of treatment. Secondary outcomes included seizure frequency and intensity reduction and EEG improvement. Assessments were performed 3 months and 1 day before starting treatment and 1, 3, 6 and 12 months after beginning the supplement. Twenty-four participants were enrolled (13 males/11 females, mean age 9.8 years, SD 4.8), 23 of whom completed the study. Patients had GRIN2B, GRIN1 and GRIN2A variants (12, 6 and 5 cases, respectively). Their clinical phenotypes showed 91% had intellectual disability (61% severe), 83% had behavioural problems, 78% had movement disorders and 58% had epilepsy. Based on the Vineland Adaptive Behavior Composite standard scores, nine children were classified as mildly impaired (cut-off score > 55), whereas 14 were assigned to the clinically severe group. An improvement was detected in the Daily Living Skills domain (P = 0035) from the Vineland Scales within the mild group. Expressive (P = 0.005), Personal (P = 0.003), Community (P = 0.009), Interpersonal (P = 0.005) and Fine Motor (P = 0.031) subdomains improved for the whole cohort, although improvement was mostly found in the mild group. The Growth Scale Values in the Cognitive subdomain of the Bayley-III Scale showed a significant improvement in the severe group (P = 0.016), with a mean increase of 21.6 points. L-serine treatment was associated with significant improvement in the median Gross Motor Function-88 total score (P = 0.002) and the mean Pediatric Quality of Life total score (P = 0.00068), regardless of severity. L-serine normalized the EEG pattern in five children and the frequency of seizures in one clinically affected child. One patient discontinued treatment due to irritability and insomnia. The trial provides evidence that L-serine is a safe treatment for children with GRIN loss-of-function variants, having the potential to improve adaptive behaviour, motor function and quality of life, with a better response to the treatment in mild phenotypes.

Intellectual-disability-associated mutations in the ceramide transport protein gene CERT1 lead to aberrant function and subcellular distribution.

The lipid molecule ceramide is transported from the endoplasmic reticulum to the Golgi apparatus for sphingomyelin production via the ceramide transport protein (CERT), encoded by CERT1. Hyperphosphorylation of CERT's serine-repeat motif (SRM) decreases its functionality. Some forms of inherited intellectual disability (ID) have been associated with a serine-to-leucine substitution in the SRM (S132L mutation) and a glycine-to-arginine substitution outside the SRM (G243R mutation) in CERT; however, it is unclear if mutations outside the SRM disrupt the control of CERT functionality. In the current investigation, we identified a new CERT1 variant (dupAA) in a patient with mild ID that resulted from a frameshift at the C-terminus of CERT1. However, familial analysis revealed that the dupAA variant was not associated with ID, allowing us to utilize it as a disease-matched negative control for CERT1 variants that are associated with ID. Biochemical analysis showed that G243R and S132L, but not dupAA, impair SRM hyperphosphorylation and render the CERT variants excessively active. Additionally, both S132L and G243R mutations but not dupAA caused the proteins to be distributed in a punctate subcellular manner. On the basis of these findings, we infer that the majority of ID-associated CERT variants may impair SRM phosphorylation-dependent repression, resulting in an increase in sphingomyelin production concurrent with CERT subcellular redistribution.

Perfil y factores pronósticos en el traumatismo craneoencefálico en la edad pediátrica / Prognostic factors and profi le in traumatic brain injury in the paediatric age

INTRODUCCIÓN: El traumatismo craneoencefálico (TCE) es una causa común de muerte y discapacidad en la población pediátrica, aunque la bibliografía en población española sea escasa. Desde la perspectiva de la vulnerabilidad temprana, los hallazgos de investigaciones recientes sugieren que la lesión cerebral temprana tiene peores secuelas y un mayor riesgo de impacto. OBJETIVOS: Analizar el perfil de la inteligencia, las funciones ejecutivas y el comportamiento, y examinar la asociación de la edad a la lesión, la gravedad del TCE y los factores ambientales para los resultados cognitivos y conductuales. PACIENTES Y MÉTODOS: Setenta y un participantes con TCE moderado a grave, con edades entre 6 y 16 años, fueron evaluados con medidas de inteligencia (cociente intelectual), funciones ejecutivas y comportamiento. RESULTADOS: Los niños con TCE tienen un mayor riesgo de discapacidad en todos los aspectos de inteligencia, funciones ejecutivas y comportamiento. Los niños que sufrieron una lesión cerebral traumática en la infancia y preescolar registraron más efectos globales en el cociente intelectual y algunos aspectos de las funciones ejecutivas. CONCLUSIONES: Los factores socioeconómicos y culturales son los mejores predictores para el cociente intelectual y el comportamiento. Estos hallazgos contribuyen a una mejor comprensión de las secuelas de TCE en los niños para ayudar en la planificación de rehabilitación y la readaptación a la vida funcional

INTRODUCTION: Traumatic brain injury (TBI) is a common cause of death and disability in the paediatric population, although the literature on the Spanish population is scarce. From the perspective of early vulnerability, recent research fi ndings suggest that early brain injury has worse sequelae and a higher risk of impact. Aims. To analyse the intelligence profi le, executive functions and behaviour, and examine the association between age at the time of the injury, severity of the TBI and environmental factors for cognitive and behavioural outcomes. PATIENTS AND METHODS: Seventy-one participants with moderate to severe TBI, from 6 to 16 years of age, were assessed with measures of intelligence (intelligence quotient), executive functions and behaviour. RESULTS: Children with TBI are at increased risk of disability in all aspects of intelligence, executive functions and behaviour. Children who suff ered a traumatic brain injury in infancy and the preschool period had more overall eff ects on intelligence quotient and some aspects of the executive functions. CONCLUSIONS: Socioeconomic and cultural factors are the best predictors for intelligence quotient and behaviour. These findings contribute to a better understanding of the sequelae of TBI in children, which will help in rehabilitation planning and re-adaptation to functional life

Discovery of Biomarker Panels for Neural Dysfunction in Inborn Errors of Amino Acid Metabolism.

Patients with inborn errors of amino acid metabolism frequently show neuropsychiatric symptoms despite accurate metabolic control. This study aimed to gain insight into the underlying mechanisms of neural dysfunction. Here we analyzed the expression of brain-derived neurotrophic factor (BDNF) and 10 genes required for correct brain functioning in plasma and blood of patients with Urea Cycle Disorders (UCD), Maple Syrup Urine Disease (MSUD) and controls. Receiver-operating characteristic (ROC) analysis was used to evaluate sensitivity and specificity of potential biomarkers. CACNA2D2 (α2δ2 subunit of voltage-gated calcium channels) and MECP2 (methyl-CpG binding protein 2) mRNA and protein showed an excellent neural function biomarker signature (AUC ≥ 0,925) for recognition of MSUD. THBS3 (thrombospondin 3) mRNA and AABA gave a very good biomarker signature (AUC 0,911) for executive-attention deficits. THBS3, LIN28A mRNA, and alanine showed a perfect biomarker signature (AUC 1) for behavioral and mood disorders. Finally, a panel of BDNF protein and at least two large neural AAs showed a perfect biomarker signature (AUC 1) for recognition of psychomotor delay, pointing to excessive protein restriction as central causative of psychomotor delay. To conclude, our study has identified promising biomarker panels for neural function evaluation, providing a base for future studies with larger samples.

Eficacia de una nueva intervención de apoyo a padres y escuelas después de un traumatismo craneoencefálico moderado o grave / Efficacy of a new parent and school-supported intervention after moderate and severe childhood traumatic brain injury

Introducción. El traumatismo craneoencefálico es una causa habitual de discapacidad adquirida durante la infancia. Las intervenciones tempranas que se centran en la participación de los padres pueden resultar efectivas para reducir las disfunciones del niño. Objetivo. Determinar la eficacia de un nuevo programa de asesoramiento dirigido a padres y escuelas en comparación con un grupo control. Pacientes y métodos. La muestra principal del estudio se obtuvo de un hospital pediátrico. La muestra final consistió en 42 niños de 6 a 16 años. Resultados. Comparando con los datos normativos, las comparaciones pre y post intragrupos mostraron una mejora significativa en el grupo de intervención parental con respecto al grupo control. Conclusiones. La superioridad del grupo de intervención parental sobre el grupo control no sólo fue estadísticamente significativa, sino también clínicamente sustancial y relevante. Los resultados del estudio sugieren que los niños con traumatismo craneoencefálico moderado o grave pueden beneficiarse de un tratamiento familiar intensivo de apoyo

Introduction. Traumatic brain injury is a common cause of acquired disability during childhood. Early interventions focusing on parenting practices may prove effective at reducing negative child outcomes. Aim. To determine the efficacy of a new counselling program aimed at parents and schools compared to a control group. Patients and methods. The main study sample was obtained from a paediatric hospital. The final sample consisted of 42 children aged between 6 and 16 years old. Results. Comparing with normative data, pre-post comparisons between groups showed a significant improvement in the parent group with respect to the control group. Conclusions. The superiority of the parental intervention group over those of the control group was not only statistically significant, but also clinically substantial and meaningful. The results of this study suggest that children with moderate to severe traumatic brain injury can benefit from an intensive supported family treatment

Subtle visuomotor deficits and reduced benefit from practice in early treated phenylketonuria.

INTRODUCTION: Phenylketonuria (PKU) is a rare metabolic disease that causes slight-to-severe neurological symptoms. Slow performance has been observed in PKU but the influence of high-order (i.e., not purely motor) deficits and of temporary variations of the phenylalanine (Phe) level on this slowness has not been fully corroborated as yet. Response speed and the effect of motor practice during the performance of a visuomotor coordination task were measured, in a group of patients with early-treated phenylketonuria (ET PKU). METHOD: We compared the performance of a group of early-treated PKU patients with ages ranging from 11 to 25 years and a control group of healthy volunteers on a computerized visuomotor task. Participants performed rapid movements towards one of five response buttons, as indicated by a visual stimulus that could appear in five different positions on a computer screen. The results of our visuomotor task were correlated with neurobiological data (Phe levels) and with neuropsychological measures of motor (finger tapping) and executive functions (Stroop task). RESULTS: The ET PKU group showed slower responses than the control group. Furthermore, an absence of a practice effect (i.e., faster response times at the end of the study) was found in the PKU group but not in the control group. Our results also revealed that this absence of practice effect correlated with higher Phe levels on the testing day with respect to the average Phe level of the previous 12 months and, although weakly, with performance on the Stroop task. CONCLUSIONS: This pattern of results indicates slower visuomotor performance and a less beneficial effect of practice in ET PKU. The correlations found among our visuomotor measures, the same-day Phe level, and the Stroop test may reflect the negative effects of dopamine reduction in brain areas involved in motor control, selective attention, and learning.

Evolución neurológica, neuropsicológica y oftalmológica tras un año de suplementación con ácido docosahexaenoico en pacientes fenilcetonúricos / Neurological, neuropsychological, and ophtalmological evolution after one year of docosahexaenoic acid supplementation in phenylketonuric patients

Introducción. La fenilcetonuria (PKU) es una enfermedad metabólica autosómica recesiva causada por la deficiencia defenilalanina hidroxilasa. El tratamiento dietético de la PKU consiste en la restricción de alimentos ricos en proteínas, loque afecta la ingestión de lípidos de los pacientes y distorsiona la relación n-3:n-6 de ácidos grasos esenciales en la dieta. Esta deficiencia puede contribuir al deterioro neurológico y visual de los pacientes. Objetivo. Evaluar los cambios en las alteraciones de la sustancia blanca, potenciales evocados visuales (PEV) y rendimiento en funciones ejecutivas y motrices en pacientes con PKU tratados precozmente tras la suplementación con ácidodocosahexaenoico (DHA).Pacientes y métodos. Se seleccionaron 21 pacientes con PKU (edad: 9-25 años), con dieta restringida en fenilalanina. Loscriterios de inclusión fueron: valores bajos de DHA eritrocitaria, retraso de latencias de la onda P100 en PEV o presencia dehiperintensidad de sustancia blanca en la resonancia magnética (RM) cerebral, y cociente intelectual > 80. Los pacientes se suplementaron con DHA (10 mg/kg/día) durante 12 meses. La evaluación se realizó al inicio del estudio y a los 12 mesesde tratamiento, e incluyó parámetros bioquímicos, RM, PEV, evaluación oftalmológica y pruebas neuropsicológicas. Resultados y conclusión. Los pacientes normalizaron los niveles de DHA tras la suplementación. La mejora en las latencias de la onda P100 y la motricidad fina fue significativa. No se evidenciaron cambios en las otras exploraciones tras el tratamiento. Es necesario proseguir la investigación para establecer una relación causa-efecto entre el tratamiento con DHA y la mejoría observada en algunas funciones neurológicas (AU)

Introduction. Phenylketonuria (PKU) is an autosomal recessive metabolic disease caused by a deficiency of phenylalanine hydroxylase. The dietary therapy for the effective management of PKU, in particular the restriction of high-protein foodsof animal-origin, compromises patients’ intake of fat and distorts the n-3:n-6 ratio of essential fatty acids in the diet. This deficiency can contribute to neurological and visual impairment. Aim. To evaluate changes in white matter alterations, visual evoked potential (VEP) latences and performance in executive and motor functions in a group of early and continuously treated PKU patients after supplementation with docosahexaneoic acid (DHA).Patients and methods. We selected 21 PKU patients with early diagnosis (age range: 9-25 years), on a Phe-restricted diet and supplemented with PKU formula. Inclusion criteria were: low erythrocyte DHA values, prolonged P100 wave latencies in VEP and/or presence of white matter hyperintensities on brain magnetic resonance imaging (MRI), and intellectual quotient > 80. All patients were treated with DHA (10 mg/kg/day) for 12 months. Assessment was conducted at baseline and after 12 months of treatment, and included biochemical parameters, brain MRI, VEP, ophthalmologic evaluation andneuropsychological tests.Results and conclusion. All the patients normalized the DHA levels after supplementation. Improvement in the P100 wavelatencies, and fine motor skills was significant. No significant improvement in the other explorations was evident aftersupplementation. Further investigations seem advisable to establish a cause-effect relationship between DHA treatmentand the slight improvement observed in some neurological functions (AU)

[Neurological, neuropsychological, and ophthalmological evolution after one year of docosahexaenoic acid supplementation in phenylketonuric patients]. / Evolucion neurologica, neuropsicologica y oftalmologica tras un ano de suplementacion con acido docosahexaenoico en pacientes fenilcetonuricos.

INTRODUCTION. Phenylketonuria (PKU) is an autosomal recessive metabolic disease caused by a deficiency of phenylalanine hydroxylase. The dietary therapy for the effective management of PKU, in particular the restriction of high-protein foods of animal-origin, compromises patients' intake of fat and distorts the n-3:n-6 ratio of essential fatty acids in the diet. This deficiency can contribute to neurological and visual impairment. AIM. To evaluate changes in white matter alterations, visual evoked potential (VEP) latencies and performance in executive and motor functions in a group of early and continuously treated PKU patients after supplementation with docosahexaneoic acid (DHA). PATIENTS AND METHODS. We selected 21 PKU patients with early diagnosis (age range: 9-25 years), on a Phe-restricted diet and supplemented with PKU formula. Inclusion criteria were: low erythrocyte DHA values, prolonged P100 wave latencies in VEP and/or presence of white matter hyperintensities on brain magnetic resonance imaging (MRI), and intellectual quotient > 80. All patients were treated with DHA (10 mg/kg/day) for 12 months. Assessment was conducted at baseline and after 12 months of treatment, and included biochemical parameters, brain MRI, VEP, ophthalmologic evaluation and neuropsychological tests. RESULTS AND CONCLUSION. All the patients normalized the DHA levels after supplementation. Improvement in the P100 wave latencies, and fine motor skills was significant. No significant improvement in the other explorations was evident after supplementation. Further investigations seem advisable to establish a cause-effect relationship between DHA treatment and the slight improvement observed in some neurological functions.

[Developmental amnesia as a focal cognitive sequela of a neonatal pathology]. / Amnesia del desarrollo como secuela cognitiva focal de patologia neonatal.

INTRODUCTION: The developmental amnesia is a recently known entity that occurs as a consequence of hypoxic-ischemic events in the perinatal period. This is a specific deficit of episodic memory with greater preservation of semantic memory and other memory components such as the immediate and working memory. It occurs in patients without apparent neurological sequelae, with normal psychomotor development and general intelligence. The developmental amnesia has been associated with bilateral involvement of the hippocampus, which is evident in some cases on magnetic resonance imaging (MRI) as signal disturbance and signs of atrophy, or reduced size of the hippocampus in brain volumetric studies. PATIENTS AND METHODS: We present six observations of developmental amnesia, their clinical, neuropsychological and neuroimaging findings. RESULTS: All of them show impaired episodic memory with preservation of semantic memory, have a normal general intelligence and follow a regular school with special educational needs. CONCLUSIONS: It is necessary to keep in mind this entity in monitoring risk newborns by their perinatal history and include the exploration of memory in neuropsychological study of these subjects. On the other hand, we highlight the specificity of the clinical and neuropsychological profile for the diagnosis of developmental amnesia even in the absence of hippocampal lesions on conventional MRI.

Amnesia del desarrollo como secuela cognitiva focal de patología neonatal / Developmental amnesia as a focal cognitive sequela of a neonatal pathology

Introducción. La amnesia del desarrollo es una entidad de reciente conocimiento que se presenta como secuela de eventos hipóxico-isquémicos en la etapa perinatal. Se trata de un déficit específico de la memoria episódica con mejor preservación e la memoria semántica y otros componentes de la memoria, como son la memoria inmediata y la de trabajo. Se presenta en pacientes sin secuelas neurológicas aparentes, con un desarrollo psicomotor y una inteligencia general normales. La amnesia del desarrollo se ha asociado a la afectación bilateral del hipocampo, evidente en algunos casos en la resonancia magnética en forma de alteración de la señal y signos de atrofia, o bien disminución del tamaño del hipocampo en estudios volumétricos cerebrales.Pacientes y métodos. Se presentan seis observaciones de amnesia del desarrollo, su cuadro clínico, exploración neuropsicológica y hallazgos de neuroimagen. Resultados. Todos ellos muestran una alteración de la memoria episódica con preservación de la memoria semántica. Presentan una inteligencia general normal y siguen una escolarización ordinaria con necesidades educativas especiales. Conclusiones. Es necesario tener presente esta entidad en el seguimiento de los recién nacidos de riesgo por sus antecedentes perinatales e incluir la exploración de la memoria en el estudio neuropsicológico de estos sujetos. Por otra parte, se señala la especificidad del cuadro clínico y del perfil neuropsicológico para el diagnóstico de la amnesia del desarrollo aun en ausencia de lesiones del hipocampo en la resonancia magnética convencional (AU)

Introduction. The developmental amnesia is a recently known entity that occurs as a consequence of hypoxic-ischemic events in the perinatal period. This is a specific deficit of episodic memory with greater preservation of semantic memory and other memory components such as the immediate and working memory. It occurs in patients without apparent neurological sequelae, with normal psychomotor development and general intelligence. The developmental amnesia hasbeen associated with bilateral involvement of the hippocampus, which is evident in some cases on magnetic resonance imaging (MRI) as signal disturbance and signs of atrophy, or reduced size of the hippocampus in brain volumetric studies. Patients and methods. We present six observations of developmental amnesia, their clinical, neuropsychological and neuroimaging findings. Results. All of them show impaired episodic memory with preservation of semantic memory, have a normal general intelligence and follow a regular school with special educational needs. Conclusions. It is necessary to keep in mind this entity in monitoring risk newborns by their perinatal history and include the exploration of memory in neuropsychological study of these subjects. On the other hand, we highlight the specificity of the clinical and neuropsychological profile for the diagnosis of developmental amnesia even in the absence of hippocampal lesions on conventional MR (AU)

Four sisters compound heterozygotes for the pre- and full mutation in fragile X syndrome and a complete inactivation of X-functional chromosome: implications for genetic counseling.

Fragile X syndrome (FXS) is a neurodevelopmental disorder and a leading monogenic form of cognitive impairment and autism. It is the most common form of inherited mental retardation in males and a significant cause of mental retardation in females. It is caused by the instability and subsequent expansion of the CGG repeat in the promoter region of the FMR1 (fragile X mental retardation 1) gene at Xq27.3. We describe a double consanguineous family with four sisters compound heterozygotes for the full and pre-mutation CGG repeat size. The index case shows clinical features of the affected males with profound mental retardation; the other three sisters also suffer from mental retardation, ranging from mild to severe. Molecular analysis reveals very similar ranges for the CGG expansions for both chromosomes in all four sisters. The phenotypic differences observed in the index case and her sisters are the total inactivation of X premutated chromosome and the total absence of FMRP (fragile X mental retardation protein). This family case raises important issues for genetic counseling in families with consanguinity and with cases of idiopathic mental retardation.

Variables predictoras de retraso mental en una unidad de monitorización videoelectroencefalográfica pediátrica. Evaluación neuropsicológica / Predictive variables for mental retardation in a Pediatric Epilepsy Monitoring Unit

de Monitorización Videoelectroencefalográfica del Hospital Sant Joan de Déu de Barcelona, y determinar los factores de riesgo para presentar retraso mental. Pacientes y métodos. Se analizan retrospectivamente las historias de los pacientes ingresados desde el inicio de la Unidad de la Epilepsia (marzo de 2005) hasta diciembre de 2008. De los 158 pacientes (edad media: 8,8 ± 5,2 años; 55,1%, sexo masculino), se analizan los datos de los pacientes con un valor de cociente intelectual (CI) estimado, mayores de 3 años y con actividad epiléptica objetivada por electroencefalograma (EEG). Se agrupan en CI menor de 70 y CI mayor o igual a 70 (63 y 47 niños, respectivamente). Todos los sujetos presentaban una epilepsia farmacorresistente. Resultados. El porcentaje de pacientes con retraso mental es significativamente más alto en pacientes que inician la epilepsia antes de los 24 meses (68,3%) que en los que la inician más tarde (27,7%). Las variables que representan un riesgo mayor para presentar retraso mental son la edad de inicio de las crisis, los hallazgos del EEG y la etiología de la epilepsia. Conclusión. Haber iniciado las crisis de forma precoz, tener una epilepsia multifocal y una etiología criptogénica son factores de mal pronóstico para el desarrollo normal de las funciones cognitivas en pacientes pediátricos con epilepsias (AU)

Aim. We sought to describe the epidemiological and clinical data from our patients in the Pediatric Epilepsy Monitoring Unit (PEMU) of the Sant Joan de Déu Hospital of Barcelona, and determine the variables of risk for mental retardation. Patients and methods. A retrospective review of PEMU reports and hospital discharge summaries from March 2005 to December 2008 was conducted. The data from patients with intelligence quotient (IQ) estimated, older than 3 years of age and with epileptic electroencephalography (EEG) activity was analyzed in 158 patients (8.8 ± 5.2 years; 55.1% boys). Of those pediatric patients, 63 had IQ less than 70 and 47 an IQ greater than or equal to 70. Intractable epilepsy was present in all of them. Results. The percentage of the patients with mental retardation is significantly higher in patients with onset of epilepsy before 24 months (68.3%) than patients with later onset (27.7%). Onset of seizures, EEG findings and epilepsy etiology are significant risk factors for mental retardation. Conclusions. Early age at seizure, multifocal epilepsy and cryptogenic etiology are factors of worse prognosis to normal development of cognitive functions in pediatric intractable epilepsy (AU)

Cognitive functions and the antioxidant system in phenylketonuric patients.

The authors studied the relationship between the antioxidant system and cognitive functions in a group of 36 early and continuously treated phenylketonuric (PKU) patients (mean age=9.7 years) and 29 controls. The authors measured antioxidant cofactors and free radical damage markers in plasma (selenium, retinol, tocopherol, coenzyme Q10, malondialdehide) and antioxidant enzymes in red blood cells (glutathione peroxidase, catalase, superoxide dismutase). The authors used neuropsychological tests to screen for several cognitive functions. PKU patients showed significantly lower values of selenium, coenzyme Q10, and catalase, and significantly higher levels of malondialdehide. PKU patients showed a significantly negative correlation between plasma selenium concentrations and several Conner's Continuous Performance Test measures (more omission errors, fluctuating attention and inconsistency of response times, and slowing reaction time as the test progressed). Selenium deficiency was thus associated with a worsened performance on the Conner's Continuous Performance Test among PKU patients. In conclusion, it is important not only to control blood Phe levels in PKU but also other nutritional components such as selenium. Selenium status seems to be associated with attention functions in these PKU patients.