The spectrum of intermediate SCN8A-related epilepsy

Objective: Pathogenic variants in SCN8A have been associated with a wide spectrum of epilepsy phenotypes, ranging from benign familial infantile seizures (BFIS) to epileptic encephalopathies with variable severity. Furthermore, a few patients with intellectual disability (ID) or movement disorders without epilepsy have been reported. The vast majority of the published SCN8A patients suffer from severe developmental and epileptic encephalopathy (DEE). In this study, we aimed to provide further insight on the spectrum of milder SCN8A-related epilepsies. Methods: A cohort of 1095 patients were screened using a next generation sequencing panel. Further patients were ascertained from a network of epilepsy genetics clinics. Patients with severe DEE and BFIS were excluded from the study. Results: We found 36 probands who presented with an SCN8A-related epilepsy and normal intellect (33%) or mild (61%) to moderate ID (6%). All patients presented with epilepsy between age 1.5 months and 7 years (mean = 13.6 months), and 58% of these became seizure-free, two-thirds on monotherapy. Neurological disturbances included ataxia (28%) and hypotonia (19%) as the most prominent features. Interictal electroencephalogram was normal in 41%. Several recurrent variants were observed, including Ile763Val, Val891Met, Gly1475Arg, Gly1483Lys, Phe1588Leu, Arg1617Gln, Ala1650Val/Thr, Arg1872Gln, and Asn1877Ser. Significance: With this study, we explore the electroclinical features of an intermediate SCN8A-related epilepsy with mild cognitive impairment, which is for the majority a treatable epilepsy.Peer reviewe

Pelizaeus-Merzbacher disease in patients with molecularly confirmed diagnosis

Pelizaeus-Merzbacher disease (PMD) is X-linked hypomyelinating leukodystrophy caused by mutations of the PLP1 gene, which codes the proteolipid protein 1. The result of mutations is abnormal myelination – hypomyelination and dysmyelination of cerebral white matter, and in some form of the disease hypomyelinating peripheral neuropathy. DNA samples from 68 patients suspected of PMD due to the clinical course and hypomyelination at magnetic resonance imaging (MRI) were analyzed. Medical history and detailed clinical course of PMD patients were also analyzed. Different mutations of the PLP1 gene were detected in 14 boys from 11 families (~20%). Amongst the molecularly confirmed patients, 13 presented classical PMD forms but clinical phenotypes varied in the severity even amongst siblings. One patient presented a severe connatal form. One mother, obligate carrier, presented complicated SPG2 (spastic paraparesis). There was no phenotype-genotype correlation in our material. In many cases PMD was suspected with a delay of many years, sometimes only after birth of another affected child in the family. Pelizaeus-Merzbacher disease was most frequently misdiagnosed as cerebral palsy

The spectrum of PLP1 gene mutations in patients with the classical form of the Pelizaeus-Merzbacher disease.

Uterine and umbilical blood flow measurements are reviewed in terms of studies carried out in uncomplicated human pregnancies. The review includes the perspective of how those estimates of flow fit with current knowledge of human fetal O2 consumption and uterine O2 and glucose consumption. From the consideration of both the O2 data and the flow measurements, we conclude that the best estimates for mean umbilical blood flow at term range between 120 and 145 ml•min-1•(kg fetus)-1. The uterine flow estimate from physiologic data would equate to ~270 ml•min-1•(kg fetus)-1. This estimate, based upon estimates of uterine O2 and glucose consumption, is much higher than some estimates made by imaging techniques. The reasons for this discrepancy are not yet established. However, given the enormous variability in uterine flow measurements made with imaging techniques, it is clear that more research into improvement in these non-invasive approaches is still required and all current estimates of uterine flow must be regarded as rather crude trials

Medulloblastoma with extensive nodularity : US, CT and MRI findings

Background: Medulloblastoma accounts for up to 25% of all paediatric CNS tumours. According to WHO classification (2007) medulloblastoma with extensive nodularity (MBEN) is a separate rare entity associated with younger age and better prognosis. Case Reports: A 9-month-old girl was admitted and examined because of macrocephaly and disturbed psychomotor development. Transfontanel ultrasound revealed dilated ventricular system and hyperechoic mass in the posterior cranial fossa. Computed tomography showed hyperdense mass in the cerebellum. Magnetic resonance imaging revealed a mass with gyriform pattern and strong contrast enhancement after gadolinium administration. Differential diagnosis included dysplastic heterotopic cortex, Lhermitte-Duclos disease, atypical teratoid/rhabdoid tumour (AT/RT), and medulloblastoma (MB). The patient was operated on. Medulloblastoma with extensive nodularity (MBEN) was finally diagnosed. The authors present and discuss three other cases of this rare entity. Conclusions: Transfontanel sonografic examination is capable of detection of the posterior fossa tumour as a cause of hydrocephalus and macrocephaly. The mass in a child’s posterior cranial fossa that is hyperdense on unenhanced CT and gyriform, nodular, and markedly enhancing on MRI may strongly suggest medulloblastoma with extensive nodularity (MBEN)

The Generation of Human iPSC Lines from Three Individuals with Dravet Syndrome and Characterization of Neural Differentiation Markers in iPSC-Derived Ventral Forebrain Organoid Model

Dravet syndrome (DRVT) is a rare form of neurodevelopmental disorder with a high risk of sudden unexpected death in epilepsy (SUDEP), caused mainly (>80% cases) by mutations in the SCN1A gene, coding the Nav1.1 protein (alfa-subunit of voltage-sensitive sodium channel). Mutations in SCN1A are linked to heterogenous epileptic phenotypes of various types, severity, and patient prognosis. Here we generated iPSC lines from fibroblasts obtained from three individuals affected with DRVT carrying distinct mutations in the SCN1A gene (nonsense mutation p.Ser1516*, missense mutation p.Arg1596His, and splicing mutation c.2589+2dupT). The iPSC lines, generated with the non-integrative approach, retained the distinct SCN1A gene mutation of the donor fibroblasts and were characterized by confirming the expression of the pluripotency markers, the three-germ layer differentiation potential, the absence of exogenous vector expression, and a normal karyotype. The generated iPSC lines were used to establish ventral forebrain organoids, the most affected type of neurons in the pathology of DRVT. The DRVT organoid model will provide an additional resource for deciphering the pathology behind Nav1.1 haploinsufficiency and drug screening to remediate the functional deficits associated with the disease

Genetic Risk Factors for Neurological Disorders in Children with Adverse Events Following Immunization: A Descriptive Study of a Polish Case Series

Studies conducted on large populations show a lack of connection between vaccination and serious neurological symptoms. However, there are isolated cases that indicate such a relationship. These reports on adverse effects following immunization (AEFI) reduce social confidence in vaccination; however, their background may be rare genetic defects. The aim of the presented study was to examine if neurological AEFI in children may be associated with variants in genes related to neurodevelopment. To identify such possible associations, a descriptive study of the Polish case series was conducted. We performed next-generation sequencing in patients who, up to 4 weeks of injection of any vaccine, manifested neurological AEFI. We included 23 previously normally developing children with first seizures that occurred after vaccination. We identified pathogenic/likely pathogenic variants in genes engaged in neurodevelopment in nine patients and variants of uncertain significance in another nine patients. The mutated genes belonged to the group of genes related to epilepsy syndromes/epileptic encephalopathy. We showed that AEFI might have a genetic background. We hypothesized that in some AEFI patients, the vaccine might only trigger neurological symptoms that would have been manifested anyway as a result of a pathogenic variant in a gene engaged in neurodevelopment