ObjectiveBiallelic variants in RARS1, encoding the cytoplasmic tRNA synthetase for arginine (ArgRS), cause a hypomyelinating leukodystrophy. This study aimed to investigate clinical, neuroradiological and genetic features of patients with RARS1‐related disease, and to identify possible genotype‐phenotype relationships.MethodsWe performed a multinational cross‐sectional survey among 20 patients with biallelic RARS1 variants identified by next‐generation sequencing techniques. Clinical data, brain MRI findings and genetic results were analyzed. Additionally, ArgRS activity was measured in fibroblasts of four patients, and translation of long and short ArgRS isoforms was quantified by western blot.ResultsClinical presentation ranged from severe (onset in the first 3 months, usually with refractory epilepsy and early brain atrophy), to intermediate (onset in the first year with nystagmus and spasticity), and mild (onset around or after 12 months with minimal cognitive impairment and preserved independent walking). The most frequent RARS1 variant, c.5A>G, led to mild or intermediate phenotypes, whereas truncating variants and variants affecting amino acids close to the ArgRS active centre led to severe phenotypes. ArgRS activity was significantly reduced in three patients with intermediate and severe phenotypes; in a fourth patient with intermediate to severe presentation, we measured normal ArgRS activity, but found translation mainly of the short instead of the long ArgRS isoform.InterpretationVariants in RARS1 impair ArgRS activity and do not only lead to a classic hypomyelination presentation with nystagmus and spasticity, but to a wide spectrum, ranging from severe, early‐onset epileptic encephalopathy with brain atrophy to mild disease with relatively preserved myelination.

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We conclude that reducing the recording time of standard EEGs to 15 min may miss abnormalities in 2.36% [95% CI: 0.63-4.09%] overall and 6.42% [95% CI: 2.2-11.8%] of those with an abnormality supportive of an epilepsy to explain the reported symptoms. This result should inform any future discussions on seeking resource-efficiencies.

PURPOSE: Bi-allelic TECPR2 variants have been associated with a complex syndrome with features of both a neurodevelopmental and neurodegenerative disorder. Here, we aim to provide a comprehensive clinical description and variant interpretation framework. METHODS: Through an international collaboration, we identified 13 individuals from 12 families with bi-allelic TECPR2-variants. We systemically reviewed clinical and molecular data of this cohort and 11 cases previously reported. Phenotypes were standardized using Human Phenotype Ontology terms. RESULTS: A cross-sectional analysis revealed global developmental delay/intellectual disability, muscular hypotonia, ataxia, hyporeflexia, respiratory infections and central/nocturnal hypopnea as core manifestations. A review of brain MRI scans demonstrated a thin corpus callosum in 59%. We evaluated 14 distinct variants. Missense variants in TECPR2 are predominantly located in the N- and C-terminal regions containing β-propeller repeats. Despite constituting nearly half of disease associated TECPR2 variants, classifying missense variants as (likely) pathogenic according to ACMG criteria remains difficult. We estimate a pathogenic variant carrier frequency of 1/1,221 in the general and 1/155 in the Jewish Ashkenazi population. CONCLUSION: Based on clinical, neuroimaging and genetic data, we provide recommendations for variant reporting, clinical assessment, and surveillance/treatment of individuals with TECPR2-associated disorder. This sets the stage for future prospective natural history studies.

Background: Acute encephalomyelopathy occurring after an allogeneic bone marrow transplant for leukaemia is a diagnostic emergency. The diagnosis can be challenging since there is a wide set of alternative diagnoses, including opportunistic infections and relapse of the leukaemia.

Mutations in , encoding a glycosyltransferase enzyme involved in α-dystroglycan glycosylation, have been recently associated with dystroglycanopathy, a well-recognized subtype of congenital muscular dystrophy (CMD). Only a few cases have been reported with-related dystroglycanopathy with variable severity ranging from mild CMD to severe muscle-eye-brain disease. Here, we describe a child with a novel homozygous nonsense mutation in . The affected child has severe neurological disease since birth, including muscle disease manifested as hypotonia, muscle weakness, and wasting with elevated creatine kinase, eye disease including microphthalmia and blindness, brain disease with extensive brain malformations including massive hydrocephalus, diffuse cobblestone-lissencephaly, deformed craniocervical junction, and pontocerebellar hypoplasia. The clinical and radiologic findings are compatible with a diagnosis of severe muscle-eye-brain disease and more specifically Walker-Warburg syndrome. A more distinct aspect of the clinical phenotype in this child is the presence of refractory epilepsy in the form of epileptic spasms, epileptic encephalopathy, and West syndrome, as well as sensorineural hearing loss. These findings could expand the phenotype of-related dystroglycanopathy. In this report, we also provide a detailed review of previously reported cases with -related dystroglycanopathy and compare them to our reported child. In addition, we study the genotype-phenotype correlation in these cases.

We present a case of acute disseminated encephalomyelitis after mastoid surgery in an 11-year-old child. The aim of this paper is to increase awareness about a previously unreported and an unusual neurological complication of cholesteatoma and mastoid surgery.

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