KCNT1- related epilepsy: An international multicenter cohort of 27 pediatric cases

ObjectiveThrough international collaboration, we evaluated the phenotypic aspects of a multiethnic cohort of KCNT1- related epilepsy and explored genotype- phenotype correlations associated with frequently encountered variants.MethodsA cross- sectional analysis of children harboring pathogenic or likely pathogenic KCNT1 variants was completed. Children with one of the two more common recurrent KCNT1 variants were compared with the rest of the cohort for the presence of particular characteristics.ResultsTwenty- seven children (15 males, mean age = 40.8 months) were included. Seizure onset ranged from 1 day to 6 months, and half (48.1%) exhibited developmental plateauing upon onset. Two- thirds had epilepsy of infancy with migrating focal seizures (EIMFS), and focal tonic seizures were common (48.1%). The most frequent recurrent KCNT1 variants were c.2800G>A; p.Ala934Thr (n = 5) and c.862G>A; p.Gly288Ser (n = 4). De novo variants were found in 96% of tested parents (23/24). Sixty percent had abnormal magnetic resonance imaging (MRI) findings. Delayed myelination, thin corpus callosum, and brain atrophy were the most common. One child had gray- white matter interface indistinctness, suggesting a malformation of cortical development. Several antiepileptic drugs (mean = 7.4/patient) were tried, with no consistent response to any one agent. Eleven tried quinidine; 45% had marked (>50% seizure reduction) or some improvement (25%- 50% seizure reduction). Seven used cannabidiol; 71% experienced marked or some improvement. Fourteen tried diet therapies; 57% had marked or some improvement. When comparing the recurrent variants to the rest of the cohort with respect to developmental trajectory, presence of EIMFS, >500 seizures/mo, abnormal MRI, and treatment response, there were no statistically significant differences. Four patients died (15%), none of sudden unexpected death in epilepsy.SignificanceOur cohort reinforces common aspects of this highly pleiotropic entity. EIMFS manifesting with refractory tonic seizures was the most common. Cannabidiol, diet therapy, and quinidine seem to offer the best chances of seizure reduction, although evidence- based practice is still unavailable.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154940/1/epi16480_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154940/2/epi16480.pd

Autoimmune Encephalitis versus Creutzfeldt-Jakob disease in a patient with typical Facio-brachial dystonic seizures: A case report with Diagnostic challenges

Background: Diagnosis of rapidly progressive dementia (RPD) is very challenging. There are many conditions that fall into category of RPD ranging from autoimmune causes to neurodegenerative causes. Autoimmune encephalitis should be readily diagnosed and treated because of its response to immunomodulators. However there is no treatment available for conditions like Creutzfeldt-Jakob disease (CJD). Case presentation: Here we present a case of anti-leucine-rich glioma inactivated 1 (LGI1) encephalitis who presented with only typical facio-brachial dystonic seizures at presentation. On follow up, patient had a rapid cognitive decline with development of myoclonic jerks, akinetic mute state and ultimately death. Neuroimaging showed presence of hyperintensities in two cortical regions namely parietal and occipital on fluid-attenuated inversion recovery (FLAIR) sequence. Electroencephalogram showed diffuse slowing with occasional periodic sharp wave complexes. Thus a diagnosis of probable CJD was made. Conclusion: Autoimmune encephalitis mimicking CJD or vice versa is not a very commonly encountered phenomenon. This case discusses the clinical overlap of these two conditions and its diagnostic dilemmas. This case presented with typical LGI1 encephalitis and in spite of therapy with immunomodulators had a rapid decline and ultimately turned out to be CJD. This has been rarely described in literature

Integration of genetic and metabolic features related to sialic acid metabolism distinguishes human breast cell subtypes

<div><p>In this report we use ‘high-flux’ tributanoyl-modified <i>N</i>-acetylmannosamine (ManNAc) analogs with natural N-acetyl as well as non-natural azido- and alkyne N-acyl groups (specifically, 1,3,4-O-Bu₃ManNAc, 1,3,4-O-Bu₃ManNAz, and 1,3,4-O-Bu₃ManNAl respectively) to probe intracellular sialic acid metabolism in the near-normal MCF10A human breast cell line in comparison with earlier stage T-47D and more advanced stage MDA-MB-231 breast cancer lines. An integrated view of sialic acid metabolism was gained by measuring intracellular sialic acid production in tandem with transcriptional profiling of genes linked to sialic acid metabolism. The transcriptional profiling showed several differences between the three lines in the absence of ManNAc analog supplementation that helps explain the different sialoglycan profiles naturally associated with cancer. Only minor changes in mRNA transcript levels occurred upon exposure to the compounds confirming that metabolic flux alone can be a key determinant of sialoglycoconjugate display in breast cancer cells; this result complements the well-established role of genetic control (e.g., the transcription of STs) of sialylation abnormalities ubiquitously associated with cancer. A notable result was that the different cell lines produced significantly different levels of sialic acid upon exogenous ManNAc supplementation, indicating that feedback inhibition of UDP-GlcNAc 2-epimerase/ManNAc kinase (GNE)—generally regarded as the ‘gatekeeper’ enzyme for titering flux into sialic acid biosynthesis—is not the only regulatory mechanism that limits production of this sugar. A notable aspect of our metabolic glycoengineering approach is its ability to discriminate cell subtype based on intracellular metabolism by illuminating otherwise hidden cell type-specific features. We believe that this strategy combined with multi-dimensional analysis of sialic acid metabolism will ultimately provide novel insights into breast cancer subtypes and provide a foundation for new methods of diagnosis.</p></div

Overview of ManNAc analog metabolism <i>via</i> sialic acid metabolism and glycosylation (SAMG) gene activity.

<p>‘High-flux’ ManNAc analogs (1,3,4-O-Bu₃ManNAc, 1,3,4-O-Bu₃ManNAz, 1,3,4-O-Bu₃ManNAl analogs) passively diffuse across the plasma membrane after which the core natural or R-modified ManNAc (i.e., ManNAc, ManNAz, or ManNAl) is released <i>via</i> non-specific carboxylesterases (<i>CES</i>) that hydrolyze the butyrate groups. ManNAc(R) is converted to sialic acids by the kinase activity of <i>GNE</i> and subsequent activities of <i>NANS</i>, and <i>NANP</i> in the cytosol; in this study these metabolites constitute ‘Compartment 1’ and are measured in aggregate using the periodate resorcinol assay. Once synthesized and dephosphorylated, sialic acid enters the nucleus where it is converted to the corresponding nucleotide sugar (e.g., CMP-Neu5Ac, CMP-Sia5Az, or CMP-Sia5Al) by <i>CMAS</i>; these activated sialic acids are then transported into the Golgi apparatus by <i>SLC35A1</i> and <i>SLC35A3</i> where a subset of the 20 human sialyltransferases created sialoglycoconjugates (primarily, N- and O- linked glyocoproteins or gangliosides [i.e., sialic acid-modified glycosphingolipids]) and these compounds constitute ‘Compartment 2’ and are also measured in aggregate using the periodate resorcinol assay (as outlined in the Materials and Methods section).</p

Transcript levels of SAMG genes and correlated sialic acid levels in ManNAc analog-treated cells.

<p>(<b>A</b>) Heat maps of SAMG genes associated with Compartment 1 and Compartment 2 in each of the breast cell lines upon analog treatment as indicated. (<b>B</b>) Compartment 1 and 2 levels of sialic acid in analog-treated cells (100 mM for 24 h) with the same data plotted in (<b>C</b>) with an expanded y-axis for the MCF10A and MDA-MB-231 lines. Although not readily apparent in the heat map color scheme, several minor but statistically-significant differences in transcript levels were observed as indicated by the asterisks (* p < 0.05, ** p < 0.01, *** p < 0.001 based on the statistical analysis presented in the supporting data <b>(Columns D-F in</b> <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0195812#pone.0195812.s007" target="_blank">S2 File</a>).</p

Metabolic profiles of Compartment 1 in analog-supplemented cells.

<p>(<b>A</b>) 3D surface plots were generated for each cell line in response to treatments with analogs; sialic acid production is shown as a function of both dose and time (AZ stands for azimuth values, El stands for elevation values, and the three plots provided for each data set are rotated to depict different vantage points). (<b>B</b>) The Reserve Capacity for each cell line was calculated based on the highest observed increase in Compartment 1 sialic acid levels in analog-supplemented cells compared to untreated controls.</p

Comparison of SAMG mRNA levels in the MCF10A, T-47D, and MDA-MB-231 breast cell lines not treated with ManNAc analog.

<p>(<b>A</b>) Pair-wise statistical analysis, * p<0.05. (<b>B</b>) Heat map based on qRT-PCR analysis. (<b>C</b>) Number of genes up- or down-regulated (or not changed) in the given comparisons across cell lines. (<b>D</b>) Background sialic acid levels in each cell by ‘Compartment’ (as defined in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0195812#pone.0195812.g001" target="_blank">Fig 1</a>).</p

‘Compartment Ratios’ of ManNAc analog-treated cells.

<p>The ratio of sialic acid in Compartment 1 (i.e., unconjugated sialometabolites) compared to Compartment 2 (i.e., predominantly glycoconjugate-bound sialic acids) was calculated for cells after 24 h of treatment with each analog at the indicated concentrations.</p

Verification of metabolic incorporation of sialometabolites into Compartment 2 glycoconjugates.

<p>(<b>A</b>) Relative levels of sialic acid species in each cell line in Compartment 1 and 2 after analog treatment (250 mM for 24 h) compared to untreated control cells are summarized to show the comparatively minor perturbation of Compartment 2 in all cases. (<b>B</b>) The presence of azido- or alkyne-modified sialic acids on the surfaces of cells was determined by labeling cells with the appropriate complementary fluorescent probe followed by FACS to quantify the overall abundance of each type of non-natural sialic acid after incorporation into sialoglyconjgates (i.e., O-linked or N-linked glycoproteins or gangliosides, as shown in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0195812#pone.0195812.g001" target="_blank">Fig 1</a>). The flow cytometry results showed very low background signal unless both the analog and labeling agent were present, indicating that robust incorporation of sialosides into sialoglycoconjugates did occur. *** indicates p < .001, error bars represent ± SEM.</p

Neutrophil dysregulation is pathogenic in idiopathic inflammatory myopathies.

Idiopathic inflammatory myopathies (IIM) are characterized by muscle inflammation and weakness, myositis-specific autoantibodies (MSAs), and extramuscular organ damage. The role of neutrophil dysregulation and neutrophil extracellular traps (NETs) in IIM is unclear. We assessed whether pathogenic neutrophil subsets (low-density granulocytes [LDGs]) and NETs were elevated in IIM, associated with clinical presentation and MSAs, and their effect on skeletal myoblasts and myotubes. Circulating NETs and LDGs were quantified and correlated with clinical measures. Specific MSAs were tested for their ability to induce NETs. NETs and neutrophil gene expression were measured in IIM biopsies. Whether NETs damage skeletal myoblasts and myotubes was tested. Circulating LDGs and NETs were increased in IIM. IIM LDGs had an enhanced ability to form NETs. LDGs and NETs correlated with IIM disease activity and muscle damage. The serum MSA anti-MDA5 correlated with circulating and tissue NETs and directly enhanced NET formation. An enhanced neutrophil gene signature was present in IIM muscle and associated with muscle injury and tissue IFN gene signatures. IIM NETs decreased the viability of myotubes in a citrullinated histone-dependent manner. Dysregulated neutrophil pathways may play pathogenic roles in IIM through their ability to directly injure muscle cells and other affected tissues