Paradigmatic de novo GRIN1 variants recapitulate pathophysiological mechanisms underlying GRIN1-related disorder clinical spectrum

Background: GRIN-related disorders (GRD), the so-called grinpathies, is a group of rare encephalopathies caused by mutations affecting GRIN genes (mostly GRIN1, GRIN2A and GRIN2B genes), which encode for the GluN subunit of the N-methyl D-aspartate (NMDA) type ionotropic glutamate receptors. A growing number of functional studies indicate that GRIN-encoded GluN1 subunit disturbances can be dichotomically classified into gain- and loss-of-function, although intermediate complex scenarios are often present. Methods: In this study, we aimed to delineate the structural and functional alterations of GRIN1 disease-associated variants, and their correlations with clinical symptoms in a Spanish cohort of 15 paediatric encephalopathy patients harbouring these variants. Results: Patients harbouring GRIN1 disease-associated variants have been clinically deeplyphenotyped. Further, using computational and in vitro approaches, we identified different critical checkpoints affecting GluN1 biogenesis (protein stability, subunit assembly and surface trafficking) and/or NMDAR biophysical properties, and their association with GRD clinical symptoms. Conclusions: Our findings show a strong correlation between GRIN1 variants-associated structural and functional outcomes. This structural-functional stratification provides relevant insights of genotypephenotype association, contributing to future precision medicine of GRIN1-related encephalo

Prevalence of DDC genotypes in patients with aromatic L-amino acid decarboxylase (AADC) deficiency and in silico prediction of structural protein changes

Aromatic L-amino acid decarboxylase (AADC) deficiency is a rare autosomal recessive genetic disorder affecting the biosynthesis of dopamine, a precursor of both norepinephrine and epinephrine, and serotonin. Diagnosis is based on the analysis of CSF or plasma metabolites, AADC activity in plasma and genetic testing for variants in the DDC gene. The exact prevalence of AADC deficiency, the number of patients, and the variant and genotype prevalence are not known. Here, we present the DDC variant (n = 143) and genotype (n = 151) prevalence of 348 patients with AADC deficiency, 121 of whom were previously not reported. In addition, we report 26 new DDC variants, classify them according to the ACMG/AMP/ACGS recommendations for pathogenicity and score them based on the predicted structural effect. The splice variant c.714+4A>T, with a founder effect in Taiwan and China, was the most common variant (allele frequency = 32.4%), and c.[714+4A>T];[714+4A>T] was the most common genotype (genotype frequency = 21.3%). Approximately 90% of genotypes had variants classified as pathogenic or likely pathogenic, while 7% had one VUS allele and 3% had two VUS alleles. Only one benign variant was reported. Homozygous and compound heterozygous genotypes were interpreted in terms of AADC protein and categorized as: i) devoid of full-length AADC, ii) bearing one type of AADC homodimeric variant or iii) producing an AADC protein population composed of two homodimeric and one heterodimeric variant. Based on structural features, a score was attributed for all homodimers, and a tentative prediction was advanced for the heterodimer. Almost all AADC protein variants were pathogenic or likely pathogenic

Prevalence of DDC genotypes in patients with aromatic L-amino acid decarboxylase (AADC) deficiency and in silico prediction of structural protein changes

Aromatic L-amino acid decarboxylase (AADC) deficiency is a rare autosomal recessive genetic disorder affecting the biosynthesis of dopamine, a precursor of both norepinephrine and epinephrine, and serotonin. Diagnosis is based on the analysis of CSF or plasma metabolites, AADC activity in plasma and genetic testing for variants in the DDC gene. The exact prevalence of AADC deficiency, the number of patients, and the variant and genotype prevalence are not known. Here, we present the DDC variant (n = 143) and genotype (n = 151) prevalence of 348 patients with AADC deficiency, 121 of whom were previously not reported. In addition, we report 26 new DDC variants, classify them according to the ACMG/AMP/ACGS recommendations for pathogenicity and score them based on the predicted structural effect. The splice variant c.714+4A>T, with a founder effect in Taiwan and China, was the most common variant (allele frequency = 32.4%), and c.[714+4A>T];[714+4A>T] was the most common genotype (genotype frequency = 21.3%). Approximately 90% of genotypes had variants classified as pathogenic or likely pathogenic, while 7% had one VUS allele and 3% had two VUS alleles. Only one benign variant was reported. Homozygous and compound heterozygous genotypes were interpreted in terms of AADC protein and categorized as: i) devoid of full-length AADC, ii) bearing one type of AADC homodimeric variant or iii) producing an AADC protein population composed of two homodimeric and one heterodimeric variant. Based on structural features, a score was attributed for all homodimers, and a tentative prediction was advanced for the heterodimer. Almost all AADC protein variants were pathogenic or likely pathogenic

Prevalence of DDC genotypes in patients with aromatic L-amino acid decarboxylase (AADC) deficiency and in silico prediction of structural protein changes

Aromatic L-amino acid decarboxylase (AADC) deficiency is a rare autosomal recessive genetic disorder affecting the biosynthesis of dopamine, a precursor of both norepinephrine and epinephrine, and serotonin. Diagnosis is based on the analysis of CSF or plasma metabolites, AADC activity in plasma and genetic testing for variants in the DDC gene. The exact prevalence of AADC deficiency, the number of patients, and the variant and genotype prevalence are not known. Here, we present the DDC variant (n = 143) and genotype (n = 151) prevalence of 348 patients with AADC deficiency, 121 of whom were previously not reported. In addition, we report 26 new DDC variants, classify them according to the ACMG/AMP/ACGS recommendations for pathogenicity and score them based on the predicted structural effect. The splice variant c.714+4A>T, with a founder effect in Taiwan and China, was the most common variant (allele frequency = 32.4%), and c.[714+4A>T];[714+4A>T] was the most common genotype (genotype frequency = 21.3%). Approximately 90% of genotypes had variants classified as pathogenic or likely pathogenic, while 7% had one VUS allele and 3% had two VUS alleles. Only one benign variant was reported. Homozygous and compound heterozygous genotypes were interpreted in terms of AADC protein and categorized as: i) devoid of full-length AADC, ii) bearing one type of AADC homodimeric variant or iii) producing an AADC protein population composed of two homodimeric and one heterodimeric variant. Based on structural features, a score was attributed for all homodimers, and a tentative prediction was advanced for the heterodimer. Almost all AADC protein variants were pathogenic or likely pathogenic

Ejercicio físico en niños con epilepsia resistente a fármacos : programa monitorizado con las nuevas tecnologías

Introducción: La epilepsia en la edad pediátrica es un problema de salud prevalente, y que tiene importantes implicaciones en la calidad de vida de los niños, así como notable sintomatología tanto psicológica como merma en su autoestima. Aunque existen algunos trabajos que analizan los beneficios del ejercicio físico para contribuir a mejorar el control de las crisis en adultos con epilepsia, no hemos encontrado estudios que lo avalen en población pediátrica. Si se han estudiado los beneficios en cuanto a calidad de vida, autoestima y mejoría de los síntomas neuropsicológicos. Por otro lado, es necesario utilizar una escala de calidad de vida que haya sido validada y que sea aplicable a la población en cuestión, ya que de otro modo, los resultados que se obtengan pueden resultar difícilmente reproducibles. Objetivos: Adaptar al español y validar la escala de calidad de vida QOLCE en su versión de 16 items en una muestra de niños con epilepsia. Conocer el efecto del ejercicio físico en el control de crisis, la Calidad de Vida Relacionada con la Salud y la condición física en niños con epilepsia resistente a fármacos; Valorar la efectividad del empleo de un sistema de monitorización telemática en el cumplimiento del programa y su mantenimiento. Metodología: Fase 1: Se tradujo y retrotradujo la versión española de la escala de calidad de vida QOLCE-16. Sobre una muestra de 75 niños con epilepsia de entre 5 y 14 años, se aplicó el formulario de calidad de vida PedsQL, QOLCE-S-16 y PSQ de sueño. Los resultados se repitieron tras una semana, para demostrar adecuada aplicabilidad, validez interna y externa. Fase 2: Se realizó un estudio prospectivo, experimental, con 24 pacientes entre 6 y 14 años diagnosticados de epilepsia resistente a fármacos, sin afectación cognitiva ni limitación funcional importante, asignados aleatoriamente a 2 grupos, uno control (GC) y otro en el que se realizó una intervención y se planificó un programa de ejercicio físico individualizado, monitorizado a distancia mediante e-mail o la utilización de una pulsera de actividad (grupo experimental, GE). Con ambos grupos, se realizaron evaluaciones pretest1, pretest2, tratamiento 1 (3 meses) y postratamiento (6 meses), con medidas en control de crisis, actividad física, y calidad de vida (PedsQL y QOLCE-16), entre otras. Resultados: Fase 1: En la versión en español del QOLCE-16 se ha constatado una adecuada fiabilidad (-Cronbach=0,882), validez convergente (correlación de Spearman=0,79) y bondad de ajuste (CFI (Comparative Fit Index)=0,98; RMSEA (Root Mean Square of Aproximation)=0,056; WRMR (Weighted Root Mean Square)=0,707. Los resultados de la versión original del QOLCE-16 fueron similares. Fase 2: No se apreció diminución significativa del número de crisis epilépticas en el GE. Sí se apreció aumento significativo del número de horas de ejercicio (aumento de 4,82 horas a la semana en el GE respecto a 0,82 en el GC), así como un mejoría en algunos parámetros de la condición física, como en la longitud de salto (aumento de 11,96 cm en GE respecto a 9,11 cm en GC) y en el tiempo para realizar 4x10 metros (descenso de 1,43 segundos en GE respecto a 0,13 en GC). La mejoría apreciada en la calidad de vida medida mediante QOLCE-16 entre el inicio del programa y los 6 meses (aumento de 3,93 puntos en el GE y de 1,18 en el GC) fue estadísticamente significativa. Esta mejoría fue especialmente significativa en las subescalas emocional y cognitiva. Conclusiones: La adaptación al español del QOLCE-16 es un instrumento sencillo, breve y adecuado para medir la calidad de vida en niños de entre 5 y 14 años con epilepsia. Un programa de ejercicio físico de 6 meses de duración, con apoyo de pulseras de actividad ha sido capaz de aumentar la cantidad de ejercicio físico que realizan los niños de entre 6 y 14 años con epilepsia resistente a fármacos, y de este modo se ha constatado una mejoría de la condición de la física y de la calidad de vida medida mediante QOLCE-16.Introduction: Pediatric epilepsy has been described as an age related-condition, and it has a strong impact on childhood quality of life. Psychological symptoms and self-esteem impairment are common facts. Although there are some studies studying the benefits of physical exercise in order to improve seizure control in adults with epilepsy, we have not found studies that support it in pediatric population. Few studieshave reported in childhood some benefits in terms of quality of life, self-esteem and improvement of neuropsychological symptoms. Therefore, it is necessary to use a validated and applicable scale of quality of life in children with epilepsy. Otherwise, findings may be difficult to reproduce. Objectives: Our first aim was to translate and validate Spanish version of 16 items-QOLCE (Quality Of Life in Children with Epilepsy) quality of life scale, in a sample of children with epilepsy. Our main objective was to measure the effect of physical exercise about seizure number, Quality of Life Related to Health and physical condition in children with drug-resistant epilepsy. We also looked for the effectiveness of a tailored-made exercise program, and telematic monitoring system in order to improve exercise assessment . Methods: Phase 1: The Spanish version of the QOLCE-16 quality of life scale was translated and retro-translated. On a sample of 75 children with epilepsy between 5 and 14 years old, the quality of life form PedsQL, QOLCE-S-16 and PSQ of sleep were applied. Tests were repeated after one week. Phase 2: A prospective, experimental study was conducted with 24 patients between 6 and 14 years old, diagnosed with drug-resistant epilepsy, without significant cognitive impairment or functional limitation, randomly assigned to 2 groups, one control (CG) and another in which an intervention was carried out and an individualized physical exercise program was programmed, monitored remotely by e-mail or the use of an activity wristband (experimental group, EG). Evaluations were performed with both groups in four moments: pretest1, pretest2, treatment 1 (3 months) and after-treatment (6 months). We asked for seizure number, physical activity, and we measured quality of life (PedsQL and QOLCE-16), and we also performed physical condition tests. Results: Phase 1: Excellent results were found in Spanish adaptation of QOLCE-16, regarding reliability (-Cronbach = 0.882), convergent validity (Spearman correlation = 0.79) and model fit (CFI (Comparative Fit Index) = 0.98, RMSEA (Root Mean Square of Approximation) = 0.056; WRMR (Weighted Root Mean Square) = 0.707. The results of the original version of QOLCE-16 were similar.Phase 2: There was no significant decrease in the number of epileptic seizures in the EG. However, there was a significant increase in the weekly exercise (increase of 4.82 hours per week in the EG compared to 0.82 in the CG), as well as an improvement in some parameters of the physical condition, such as in the jump length (increase of 11.96 cm in EG compared to 9.11 cm in CG) and in the time to perform 4x10 meters (decrease of 1.43 seconds in EG compared to 0.13 in CG). The improvement seen in the quality of life measured by QOLCE-16 between the start of the program and 6 months later (increase of 3.93 points in the EG and 1.18 in the CG) was statistically significant. This improvement was especially significant in the emotional and cognitive subscales. Conclusions: The Spanish adaptation of the QOLCE-16 is a short, brief and adequate instrument to measure the quality of life in children between 5 and 14 years old with epilepsy. A 6-month physical exercise program, supported by activity wristbands, has increased the amount of physical exercise performed by children between 6 and 14 years old with drug-resistant epilepsy.It alsso has been related with an improvement in physical condition and quality of life measured by QOLCE-16

Urinary sulphatoxymelatonin as a biomarker of serotonin status in biogenic amine-deficient patients

Abstract Melatonin is synthesized from serotonin and it is excreted as sulphatoxymelatonin in urine. We aim to evaluate urinary sulphatoxymelatonin as a biomarker of brain serotonin status in a cohort of patients with mutations in genes related to serotonin biosynthesis. We analized urinary sulphatoxymelatonin from 65 healthy subjects and from 28 patients with genetic defects. A total of 18 patients were studied: 14 with autosomal dominant and recessive guanosine triphosphate cyclohydrolase-I deficiency; 3 with sepiapterin reductase deficiency; and 1 with aromatic L-amino acid decarboxylase deficiency. Further 11 patients were studied after receiving serotoninergic treatment (serotonin precursors, monoamine oxidase inhibitors, selective serotonin re-uptake inhibitors): 5 with aromatic L-amino acid decarboxylase deficiency; 1 with sepiapterin reductase deficiency; 3 with dihydropteridine reductase deficiency; and 2 with 6-pyruvoyltetrahydropterin synthase deficiency. Among the patients without therapy, 6 presented low urinary sulphatoxymelatonin values, while most of the patients with guanosine triphosphate cyclohydrolase-I deficiency showed normal values. 5 of 11 patients under treatment presented low urine sulphatoxymelatonin values. Thus, decreased excretion of sulphatoxymelatonin is frequently observed in cases with severe genetic disorders affecting serotonin biosynthesis. In conclusion, sulphatoxymelatonin can be a good biomarker to estimate serotonin status in the brain, especially for treatment monitoring purposes

A new blood DNA methylation signature for Koolen-de Vries syndrome: Classification of missense KANSL1 variants and comparison to fibroblast cells

Pathogenic variants in KANSL1 and 17q21.31 microdeletions are causative of Koolen-de Vries syndrome (KdVS), a neurodevelopmental syndrome with characteristic facial dysmorphia. Our previous work has shown that syndromic conditions caused by pathogenic variants in epigenetic regulatory genes have identifiable patterns of DNA methylation (DNAm) change: DNAm signatures or episignatures. Given the role of KANSL1 in histone acetylation, we tested whether variants underlying KdVS are associated with a DNAm signature. We profiled whole-blood DNAm for 13 individuals with KANSL1 variants, four individuals with 17q21.31 microdeletions, and 21 typically developing individuals, using Illumina's Infinium EPIC array. In this study, we identified a robust DNAm signature of 456 significant CpG sites in 8 individuals with KdVS, a pattern independently validated in an additional 7 individuals with KdVS. We also demonstrate the diagnostic utility of the signature and classify two KANSL1 VUS as well as four variants in individuals with atypical clinical presentation. Lastly, we investigated tissue-specific DNAm changes in fibroblast cells from individuals with KdVS. Collectively, our findings contribute to the understanding of the epigenetic landscape related to KdVS and aid in the diagnosis and classification of variants in this structurally complex genomic region

Impact of COVID19 pandemic on patients with rare diseases in Spain, with a special focus on inherited metabolic diseases

The Covid-19 pandemic soon became an international health emergency raising concern about its impact not only on physical health but also on quality of life and mental health. Rare diseases are chronically debilitating conditions with challenging patient care needs. We aimed to assess the quality of life and mental health of patients with rare diseases in Spain, with a special focus on inherited metabolic disorders (IMD). A prospective case-control study was designed, comparing 459 patients suffering from a rare disease (including 53 patients with IMD) and 446 healthy controls. Quality of life (QoL) and mental health were assessed using validated scales according to age: KINDL-R and the Pediatric Symptom Checklist (PSC) for children and the WhoQoL-Bref questionnaire, GAD and PHQ-9 in adults. First, children and adults (but not adolescents) with IMD showed greater psychological effects than controls (p = 0.022, p = 0.026 respectively). Second, when comparing QoL, only adult patients with IMD showed worse score than controls (66/100 vs 74,6/100 respectively, p = 0.017). Finally, IMD had better quality of life than other rare neurological and genetic diseases (p = 0.008) or other rare diseases (p < 0.001 respectively) but similar alteration of the mental status. Our data show that the pandemic had a negative impact on mental health that is more evident in the group of patients with IMD. Young age would behave as a protective factor on the perception of QoL. Furthermore, patients with IMD show a better QoL than other rare diseases