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 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 endpoints 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, Child Behavior Checklist and the Caregiver-Teacher Report Form following 12 months treatment. Secondary outcomes included seizure frequency and intensity reduction and electroencephalography improvement. Assessments were performed 3 months and 1 day before starting treatment and 1-3-6-12 months after the beginning of 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). Clinical phenotype showed: 91% intellectual disability (61% severe), 83% behavioral problems, 78% movement disorders and 58% with epilepsy. Based on Vineland Adaptive Behavior Composite standard score, nine children were classified as mildly impaired level group (cut-off > 55), whereas 14 were assigned to the clinically severe group. An improvement was detected in Daily Living Skills domain (P = 0,035) 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. Growth Score Values cognitive subdomain on the Bayley-III 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 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 the adaptive, motor function and quality of life, with a better response to the treatment in mild phenotypes.

Functional effects of disease-associated variants reveal that the S1-M1 linker of the NMDA receptor critically controls channel opening.

The short pre-M1 helix within the S1-M1 linker (also referred to as the pre-M1 linker) between the agonist-binding domain (ABD, S1) and the M1 transmembrane helix of the NMDA receptor (NMDAR) is devoid of missense variants within the healthy population but is a locus for de novo pathogenic variants associated with neurological disorders. Several de novo variants within this helix have been identified in patients presenting early in life with intellectual disability, developmental delay, and/or epilepsy. In this study, we evaluated functional properties for twenty variants within the pre-M1 linker in GRIN1, GRIN2A, and GRIN2B genes, including six novel missense variants. The effects of pre-M1 variants on agonist potency, sensitivity to endogenous allosteric modulators, response time course, channel open probability, and surface expression were assessed. Our data indicated that virtually all of the variants evaluated altered channel function, and multiple variants had profound functional consequences, which may contribute to the neurological conditions in the patients harboring the variants in this region. These data strongly suggest that the residues within the pre-M1 helix play a key role in channel gating and are highly intolerant to genetic variation.

Intrahepatic Cholestasis Is a Clinically Significant Feature Associated with Natural History of X-Linked Myotubular Myopathy (XLMTM): A Case Series and Biopsy Report.

X-linked myotubular myopathy (XLMTM) is a rare, life-threatening congenital myopathy characterized by profound skeletal muscle weakness, respiratory distress, and motor dysfunction. However, pathology is not limited to muscle and can be associated with life-threatening hepatic peliosis. Hepatobiliary disease has been reported in up to 17% of XLMTM patients but has not been extensively characterized. We report on five XLMTM patients who experienced intrahepatic cholestasis in their disease natural history, illustrating the need to further investigate these manifestations. These patients shared presentations that included pruritus, hypertransaminemia, and hyperbilirubinemia with normal gamma-glutamyl transferase, following infection or vaccination. Three patients who had genetic testing showed no evidence of genetic mutations associated with familial cholestasis. In one patient, progression to cirrhotic, decompensated liver disease occurred. Further investigations into the molecular pathomechanism underpinning these clinical observations in XLMTM patients will be important for informing patient care.

A novel dominant mutation in CRYAB gene leading to a severe phenotype with childhood onset.

BACKGROUND: αB-crystallin is a promiscuous protein involved in numerous cell functions. Mutations in CRYAB have been found in patients with different pathological phenotypes that are not properly understood. Patients can present different diseases like cataracts, muscle weakness, myopathy, cardiomyopathy, respiratory insufficiency or dysphagia, but also a variable combination of these pathologies has been found. These mutations can show either autosomal dominant or recessive mode of inheritance and variable penetrance and expressivity. This is the first report of congenital cataracts and myopathy described in childhood due to a CRYAB mutation with autosomal dominant mode of inheritance. METHODS: The whole exome sequence was subjected to phenotype-driven analysis and a novel variant in CRYAB was detected: c.514delG, p.(Ala172ProfsTer14). The mutation was located in the C-terminal domain of the protein, which is essential for chaperone activity. The deduced protein was analyzed searching for alterations of the relevant physico-chemical properties described for this domain. A muscle biopsy was also tested for CRYAB with immunohistochemical and histoenzymatic techniques. RESULTS: CRYAB displayed a mild immunoreactivity in the subsarcolemmal compartment with no pathological sarcoplasmic accumulation. It agrees with an alteration of the physico-chemical properties predicted for the C-terminal domain: hydrophobicity, stiffness, and isomerization. CONCLUSIONS: The described mutation leads to elongation of the protein at the carboxi-terminal domain (CTD) with altered properties, which are essential for solubility and activity. It suggests that can be the cause of the severe conditions observed in this patient.

Síndrome de West criptogénico: perfil clínico, respuesta al tratamiento y factores pronósticos / Cryptogenic West syndrome: Clinical profile, response to treatment and prognostic factors

INTRODUCCIÓN: El síndrome de West (SW) es una encefalopatía epiléptica dependiente de la edad con pronóstico variable según la etiología subyacente, no siempre identificada. OBJETIVOS: Definir el perfil del SW criptogénico en nuestro medio, subgrupo menos estudiado de forma aislada. Estudiar su evolución, respuesta a los distintos tratamientos y establecer factores pronósticos. PACIENTES Y MÉTODOS: Revisión de historias clínicas de 16 pacientes diagnosticados de SW criptogénico durante el período 2000-2015. El tiempo de seguimiento medio fue 6,6 años y mínimo de 2 años. RESULTADOS: 11 de 16 fueron varones, la edad media de inicio fue de 6 meses y 6/16 presentaban antecedente familiar de epilepsia idiopática. El tratamiento de primera línea con vigabatrina tuvo respuesta electroclínica en 5/16 pacientes, respondiendo los casos restantes a hormona adrenocorticotropa (ACTH). El 44% de los pacientes evolucionaron a otras epilepsias, sin diferencia entre los tratados con vigabatrina o ACTH. Se obtuvo un mayor número de efectos adversos con la ACTH, no se evidenció afectación retiniana con la vigabatrina. Durante el seguimiento se llegó a la causa etiológica en 2/16. El sexo femenino, el comienzo tardío y el control precoz de la hipsarritmia resultaron factores de buen pronóstico. CONCLUSIONES: El pronóstico global del SW criptogénico resultó más grave de los esperado. Aunque la incidencia de síndrome de Lennox-Gastaut fue baja, la epilepsia focal resultó la evolución más frecuente apareciendo en los 2 primeros años del diagnóstico. La respuesta inicial a vigabatrina fue menor a la esperada, pero el resultado a largo plazo resultó superponible a la ACTH

INTRODUCTION: West syndrome (WS) is an age-dependent epileptic encephalopathy in which the prognosis varies according to the, not always identified, underlying origin. OBJECTIVES: To define the profile of cryptogenic (a least studied isolated sub-group) WS, in Spain. To study its outcome, response to different treatments, and to establish prognostic factors. PATIENTS AND METHODS: The study included a review of the medical records of 16 patients diagnosed with cryptogenic WS during the period, 2000-2015. The mean follow-up time was 6.6 years, with a minimum of 2 years. RESULTS: The large majority (11/16) were male. The mean age at onset was 6 months, and 6/16 had a family history of idiopathic epilepsy. The first line treatment with vigabatrin had an electrical-clinical response in 5/16 patients, with the remaining cases responding to adrenocorticotropic hormone (ACTH). Almost half (44%) of the patients progressed to other types of epilepsy, with no difference between those treated with vigabatrin or ACTH. A greater number of adverse effects were obtained with ACTH, with no retinal involvement being observed with vigabatrin. The aetiological cause was found in 2/16. Being female, late onset, and early control of the hypsarrhythmia, were factors of a good prognosis. CONCLUSIONS: The overall prognosis of cryptogenic WS was more serious than expected. Although the incidence of Lennox-Gastaut syndrome was low, the progression to focal epilepsy was the most common, with it appearing within the first 2 years of the diagnosis. The initial response to vigabatrin was lower than expected, but the long-term result was comparable to ACTH

[Cryptogenic West syndrome: Clinical profile, response to treatment and prognostic factors]. / Síndrome de West criptogénico: perfil clínico, respuesta al tratamiento y factores pronósticos.

INTRODUCTION: West syndrome (WS) is an age-dependent epileptic encephalopathy in which the prognosis varies according to the, not always identified, underlying origin. OBJECTIVES: To define the profile of cryptogenic (a least studied isolated sub-group) WS, in Spain. To study its outcome, response to different treatments, and to establish prognostic factors. PATIENTS AND METHODS: The study included a review of the medical records of 16 patients diagnosed with cryptogenic WS during the period, 2000-2015. The mean follow-up time was 6.6 years, with a minimum of 2 years. RESULTS: The large majority (11/16) were male. The mean age at onset was 6 months, and 6/16 had a family history of idiopathic epilepsy. The first line treatment with vigabatrin had an electrical-clinical response in 5/16 patients, with the remaining cases responding to adrenocorticotropic hormone (ACTH). Almost half (44%) of the patients progressed to other types of epilepsy, with no difference between those treated with vigabatrin or ACTH. A greater number of adverse effects were obtained with ACTH, with no retinal involvement being observed with vigabatrin. The aetiological cause was found in 2/16. Being female, late onset, and early control of the hypsarrhythmia, were factors of a good prognosis. CONCLUSIONS: The overall prognosis of cryptogenic WS was more serious than expected. Although the incidence of Lennox-Gastaut syndrome was low, the progression to focal epilepsy was the most common, with it appearing within the first 2 years of the diagnosis. The initial response to vigabatrin was lower than expected, but the long-term result was comparable to ACTH.

Co-segregation of a homozygous SMN1 deletion and a heterozygous PMP22 duplication in a patient.

Despite co-segregation of two different genetic neurological disorders within a family is rare, clinicians should take into consideration this possibility in patients presenting with unusual complex phenotypes or with unexpected electrophysiological findings. Here, we report a Spanish 11-month-old patient with spinal muscular atrophy type 2 and Charcot-Marie-Tooth 1A.

Autoimmune post-herpes simplex encephalitis of adults and teenagers.

OBJECTIVE: To report 14 patients with immune-mediated relapsing symptoms post-herpes simplex encephalitis (HSE) and to compare the clinical and immunologic features of the teenage and adult group with those of young children. METHODS: Prospective observational study of patients diagnosed between June 2013 and February 2015. Immunologic techniques have been reported previously. RESULTS: Among the teenage and adult group (8 patients, median age 40 years, range 13-69; 5 male), 3 had an acute symptom presentation suggesting a viral relapse, and 5 a presentation contiguous with HSE suggesting a recrudescence of previous deficits. Seven patients developed severe psychiatric/behavioral symptoms disrupting all social interactions, and one refractory status epilepticus. Blepharospasm occurred in one patient. Five patients had CSF antibodies against NMDA receptor (NMDAR) and 3 against unknown neuronal cell surface proteins. In 5/6 patients, the brain MRI showed new areas of contrast enhancement that decreased after immunotherapy and clinical improvement. Immunotherapy was useful in 7/7 patients, sometimes with impressive recoveries, returning to their baseline HSE residual deficits. Compared with the 6 younger children (median age 13 months, range 6-20, all with NMDAR antibodies), the teenagers and adults were less likely to develop choreoathetosis (0/8 vs 6/6, p < 0.01) and decreased level of consciousness (2/8 vs 6/6, p < 0.01) and had longer delays in diagnosis and treatment (interval relapse/antibody testing 85 days, range 17-296, vs 4 days, range 0-33, p = 0.037). CONCLUSION: In teenagers and adults, the immune-mediated relapsing syndrome post-HSE is different from that known in young children as choreoathetosis post-HSE and is underrecognized. Prompt diagnosis is important because immunotherapy can be highly effective.

Psicosis infantil secundaria a metilfenidato / Infantile psychosis secondary to methylphenidate

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Síndrome de West: etiología, opciones terapéuticas, evolución clínica y factores pronósticos / West syndrome: aetiology, therapeutic options, clinical course and prognostic factors

Introducción. El síndrome de West es una epilepsia dependiente de la edad que asocia espasmos infantiles, hipsarritmia y un retraso o detención en el desarrollo psicomotor, aunque este último no es imprescindible. Objetivos. Definir el perfil del síndrome de West en nuestro medio atendiendo a la etiología, semiología, respuesta a distintas opciones terapéuticas y aparición de efectos adversos, y establecer factores pronósticos que determinen la evolución. Pacientes y métodos. Se ha elaborado un documento de recogida de datos en el que se constatan los criterios de inclusión. La recogida de datos se ha realizado mediante la revisión de historias clínicas de los pacientes diagnosticados de síndrome de West en el período comprendido entre enero de 2003 y enero de 2009. Posteriormente, se ha realizado un estudio estadístico con análisis descriptivo y se ha establecido el nivel de significación estadística de los posibles factores pronósticos. Resultados. El estudio abarcó 70 pacientes. La etiología sintomática fue predominante, destacando la hipoxia-isquemia como causa principal. Respondió a vigabatrina el 58% de los pacientes, independientemente de la etiología. Más del 80% de los pacientes en tratamiento con hormona adrenocorticotropa quedaron libres de crisis y sin hipsarritmia. Casi la mitad de los pacientes evolucionó a otras epilepsias. Conclusiones. Los factores de mal pronóstico estadísticamente significativos fueron: existencia de antecedentes prenatales, antecedentes neonatales, etiología sintomática, edad de inicio inferior a 4 meses, crisis epilépticas antes del inicio de los espasmos y fuera del período neonatal, y retraso en el desarrollo psicomotor previo al inicio de los espasmos (AU)

Introduction. West syndrome is an age-specific form of epilepsy that associates infantile spasms, hypsarrhythmia and a delay in or the complete stoppage of psychomotor development, although this last case is not essential. Aims. To define the profile of West syndrome in our environment by taking into account its aetiology, semiology, response to different therapeutic options and the appearance of side effects, as well as to establish prognostic factors that determine its course. Patients and methods. A data collection document stating the eligibility criteria was drafted. Data were collected by reviewing the medical records of patients diagnosed with West syndrome during the period between January 2003 and January 2009. Later, a statistical study was conducted with descriptive analysis and the level of statistical significance of the possible prognostic factors was established. Results. The study included 70 patients. There was a predominance of symptomatic aetiology, with hypoxia-ischaemia as the main cause. Regardless of the aetiology, 58% of patients responded to treatment with vigabatrine. Over 80% of patients being treated with adrenocorticotropic hormone were finally seizure-free and without hypsarrhythmia. Almost half the patients progressed to other epilepsies. Conclusions. The statistically significant poor prognostic factors were: existence of a prenatal history, neonatal history, symptomatic aetiology, age of onset below 4 months, epileptic seizures before the onset of the spasms and outside the neonatal period, and delayed psychomotor development prior to the onset of the spasms (AU)

Somatic mosaicism for Y120X mutation in the MECP2 gene causes atypical Rett syndrome in a male.

Rett Syndrome (RS; MIM_312750) is a severe and progressive neurodevelopmental disorder affecting principally females. Mutations in X-Linked MECP2 gene (methyl CpG-binding protein 2; MIM_300005) have been reported as being the major cause of RS. Mutations in this gene have been described as cause of wide spectrum of neurological disorders and mental retardation in males. In some cases, mutations in MECP2 in males produce clinical picture similar to RS. Here we report the identification of the novel truncating mutation Y120X in a 4-year-old child with atypical RS phenotype. Chromosome analysis showed a normal karyotype, and blood DNA and tissue DNA analysis reveal a mosaic for the mutation. Patient's mother DNA analysis showed that this is a de novo mutation, that has never been described before in any female or male case of RS.

Reacciones adversas cardiovasculares secundarias al tratamiento con metilfenidato / No disponible

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