Developmental and epileptic encephalopathies (DEE) are a group of severe epilepsies that usually present with intractable seizures, developmental delay, and often have elevated risk for premature mortality. Numerous genes have been identified as a monogenic cause of DEE, including KCNB1. The voltage-gated potassium channel K_VKCNB1, is primarily responsible for delayed rectifier potassium currents that are important regulators of excitability in electrically excitable cells, including neurons. In addition to its canonical role as a voltage-gated potassium conductance, K_VKCNB1-p.G379R was identified in an infant with epileptic spasms, and atonic, focal and tonic-clonic seizures that were refractory to treatment with standard antiepileptic drugs. Previous work demonstrated deficits in potassium conductance, but did not assess non-conducting functions. To determine if the G379R variant affected K_VVVVVVKcnb1^G379R into mice using CRISPR/Cas9 genome editing. We characterized neuronal expression, neurological and neurobehavioral phenotypes of Kcnb1^G379R/+ (Kcnb1^R/+) and Kcnb1^G379R/G379R (Kcnb1^R/R) mice. Immunohistochemistry studies on brains from Kcnb1^+/+, Kcnb1^R/+ and Kcnb1^R/R mice revealed genotype-dependent differences in the expression levels of K_VVKcnb1^R/+ and Kcnb1^R/R mice displayed profound hyperactivity, repetitive behaviors, impulsivity and reduced anxiety. Spontaneous seizures were observed in Kcnb1^R/R mice, as well as seizures induced by exposure to novel environments and/or handling. Both Kcnb1^R/+ and Kcnb1^R/R mutants were more susceptible to proconvulsant-induced seizures. In addition, both Kcnb1^R/+ and Kcnb1^R/R mice exhibited abnormal interictal EEG activity, including isolated spike and slow waves. Overall, the Kcnb1^G379R mice recapitulate many features observed in individuals with DEE due to pathogenic variants in KCNB1. This new mouse model of KCNB1-associated DEE will be valuable for improving the understanding of the underlying pathophysiology and will provide a valuable tool for the development of therapies to treat this pharmacoresistant DEE.

Keywords: Autism spectrum disorder; Developmental disorder; Encephalopathy; Epilepsy; K(V)2.1; Voltage-gated ion channels; Voltage-gated potassium channels.

The KCNB1 gene variants were differentially associated with cancers. However, their association with colorectal cancer has not yet been explored. We investigated the contribution of the KCNB1 gene variants rs3331, rs1051295, and indel (insertion/deletion) rs11468831 Polymorphism as predictors of the treatment response in colorectal cancer patients. A retrospective study, which involved 291 Tunisian colorectal cancer patients (aged 60.0 ± 13.1 years), who were stratified into responder and non-responder groups, according to TNM stages and their responsiveness to chemotherapy based on fluorouracil. KCNB1 genotyping was performed with amplification-refractory mutation system-polymerase chain reaction, and was confirmed by Sanger sequencing. Sex-specific response was found and colorectal cancer females are less likely to achieve a positive response during the chemotherapy strategy, compared to males. Weight and body mass index, tumor size, and tumor localization are considered as predictive factors to treatment responsiveness. Carriage of rs11468831 Ins allele was significantly associated with successful therapy achievement (p adjusted < 0.001). Stratification of colorectal cancer patients' response according to tumor localization and TNM stages reveals negative association of rs3331 Major allele to treatment response among the patients with advanced cancer stages (subgroup G2). The presence of rs3331 (homozygous minor) C/C genotype was positively associated with decline in carcino-embryonic antigen (p = 0.043) and CA19-9 (p = 0.014) serum levels. On the other hand, the presence of rs1051295 (homozygous minor) A/A genotype was correlated with marked decline in CA19-9 serum levels. KCNB1 haplotype did not reveal any association between haplotypes and treatment response. The results obtained suggest that gender-specific strategies for screening treatment and prevention protocols as well as KCNB1 variants may constitute an effective model for ongoing personalization medicine.

Keywords: CA19-9; CEA; KCNB1; TNM stages; colorectal cancer; gender; personalized medicine; treatment response.

Background: Colorectal cancer (CRC) is the third most diagnosed malignancy worldwide. The global burden is expected to increase along with ongoing westernized behaviors and lifestyle. The etiology of CRC remains elusive and most likely combines environmental and genetic factors. The Kv2.1 potassium channel encoded by KCNB1 plays a collection of roles in malignancy of cancer and may be a key factor of CRC susceptibility. Our study provides baseline association between Tunisian CRC and interactions between KCNB1 variants and lifestyle factors.

Methods: A case-control study involving 300 CRC patients, and 300 controls was conducted Patients were carefully phenotyped and followed till the end of study. KCNB1 genotyping was confirmed by Sanger sequencing. Bivariate and multivariable logistic regression analyses were used to assess the clinical status, lifestyle and study polymorphisms association with CRC.

Results: We noted significant gender association with CRC occurrence. Moreover, CRC risk increases with high meat and fat consumption, alcohol use and physical activity (PA). Carriage of rs1051296 A/G and both rs11468831 ins/del and del/del genotypes (p < 0.001) were significantly associated with CRC risk. Analysis according to gender reveals correlation of rs1051295 A/G, rs11468831 non ins/ins (p = 0.01) with CRC susceptibility regardless of patients' gender while rs3331 T/C (p = 0.012) was associated with females. Stratification study according to malignancy site; Rectal Cancer (RC) and Colon Cancer (CC), reveals increasing RC risk by gender and high meat and fat consumption, alcohol use and PA. However, additional association with high brine consumption was noted for CC. The rs1051295 A/G (p = 0.01) was associated with RC risk. Increased CC risk was associated with carriage of rs1051295 A/G, rs11168831 (del/del) and (ins/del) genotypes.

Conclusion: The risk of CRC increases with modifiable factors by Western influences on Tunisian lifestyle such as alcohol use, high fat consumption and possibly inadequate intake of vegetables. In addition, KCNB1 polymorphisms also markedly influence CRC susceptibility. Our study establishes key elements of a baseline characterization of clinical state, Western influenced lifestyle and KCNB1 variants associated with Tunisian CRC.

Keywords: Cancer prevention; Colorectal Cancer; KCNB1; Polymorphisms; Western lifestyle.

Gastrin signaling mediated through cholecystokinin-2 receptor (CCK2R) and its downstream molecules is altered in pancreatic cancer. CCK2R antagonists, YF476 (netazepide) and JNJ-26070109, were tested systematically for their effect on pancreatic intraepithelial neoplasia (PanIN) progression to pancreatic ductal adenocarcinoma (PDAC) in Kras^G12D mice. After dose selection using wild-type mice, six-week-old p48^Cre/+ -LSL-Kras^G12D (22-24 per group) genetically engineered mice (GEM) were fed AIN-76A diets containing 0, 250, or 500 ppm JNJ-26070109 or YF-476 for 38 weeks. At termination, pancreata were collected, weighed, and evaluated for PanINs and PDAC. Results demonstrated that control-diet-fed mice showed 69% (males) and 33% (females) incidence of PDAC. Administration of low and high dose JNJ-26070109 inhibited the incidence of PDAC by 88% and 71% (P < .004) in male mice and by 100% and 24% (P > .05) in female mice, respectively. Low and high dose YF476 inhibited the incidence of PDAC by 74% (P < .02) and 69% (P < .02) in male mice and by 45% and 33% (P > .05) in female mice, respectively. Further, transcriptome analysis showed downregulation of Cldn1, Sstr1, Apod, Gkn1, Siglech, Cyp2c44, Bnc1, Fmo2, 623169, Kcne4, Slc27a6, Cma1, Rho GTPase activating protein 18, and Gpr85 genes in JNJ-26070109-treated mice compared with untreated mice. YF476-treated mouse pancreas showed downregulation of Riks, Zpbp, Ntf3, Lrrn4, Aass, Skint3, Kcnb1, Dgkb, Ddx60, and Aspn gene expressions compared with untreated mouse pancreas. Overall, JNJ-26070109 showed better chemopreventive efficacy than YF476. However, caution is recommended when selecting doses, as the agents appeared to exhibit gender-specific effects.

UNASSIGNED

Emerging evidence has suggested that the genetic background of gestational diabetes mellitus (GDM) was analogous to type 2 diabetes mellitus. In contrast to type 2 diabetes mellitus, the genetic studies for GDM were limited. Accordingly, the aim of the present study was to extensively explore the influence of micro-ribonucleic acid-binding single-nucleotide polymorphisms (SNPs) in type 2 diabetes mellitus candidate loci on GDM susceptibility in Chinese.

METHODS

A total of 839 GDM patients and 900 controls were enrolled. Six micro-ribonucleic acid-binding SNPs were selected from 30 type 2 diabetes mellitus susceptibility loci and genotyped using TaqMan allelic discrimination assays.

RESULTS

The minor allele of three SNPs, PAX4 rs712699 (OR 1.366, 95% confidence interval 1.021-1.828, P = 0.036), KCNB1 rs1051295 (OR 1.579, 95% confidence interval 1.172-2.128, P = 0.003) and MFN2 rs1042842 (OR 1.398, 95% confidence interval 1.050-1.862, P = 0.022) were identified to significantly confer higher a risk of GDM in the additive model. The association between rs1051295 and increased fasting plasma glucose (b = 0.006, P = 0.008), 3-h oral glucose tolerance test plasma glucose (b = 0.058, P = 0.025) and homeostatic model assessment of insulin resistance (b = 0.065, P = 0.017) was also shown. Rs1042842 was correlated with higher 3-h oral glucose tolerance test plasma glucose (b = 0.056, P = 0.028). However, no significant correlation between the other included SNPs (LPIN1 rs1050800, VPS26A rs1802295 and NLRP3 rs10802502) and GDM susceptibility were observed.

CONCLUSIONS

The present findings showed that micro-ribonucleic acid-binding SNPs in type 2 diabetes mellitus candidate loci were also associated with GDM susceptibility, which further highlighted the similar genetic basis underlying GDM and type 2 diabetes mellitus.

Entropion is an inward rolling of the eyelid allowing contact between the eyelashes and cornea that may lead to blindness if not corrected. Although many mammalian species, including humans and dogs, are afflicted by congenital entropion, no specific genes or gene regions related to development of entropion have been reported in any mammalian species to date. Entropion in domestic sheep is known to have a genetic component therefore, we used domestic sheep as a model system to identify genomic regions containing genes associated with entropion. A genome-wide association was conducted with congenital entropion in 998 Columbia, Polypay, and Rambouillet sheep genotyped with 50,000 SNP markers. Prevalence of entropion was 6.01%, with all breeds represented. Logistic regression was performed in PLINK with additive allelic, recessive, dominant, and genotypic inheritance models. Two genome-wide significant (empirical P<0.05) SNP were identified, specifically markers in SLC2A9 (empirical P = 0.007; genotypic model) and near NLN (empirical P = 0.026; dominance model). Six additional genome-wide suggestive SNP (nominal P<1x10(-5)) were identified including markers in or near PIK3CB (P = 2.22x10(-6); additive model), KCNB1 (P = 2.93x10(-6); dominance model), ZC3H12C (P = 3.25x10(-6); genotypic model), JPH1 (P = 4.68x20(-6); genotypic model), and MYO3B (P = 5.74x10(-6); recessive model). This is the first report of specific gene regions associated with congenital entropion in any mammalian species, to our knowledge. Further, none of these genes have previously been associated with any eyelid traits. These results represent the first genome-wide analysis of gene regions associated with entropion and provide target regions for the development of sheep genetic markers for marker-assisted selection.

Background: Gastric and colorectal cancers are the most common malignant tumours, leading to a significant number of cancer-related deaths worldwide. Recently, increasing evidence has demonstrated that cancer cells exhibit a differential expression of potassium channels and this can contribute to cancer progression. However, their expression and localisation at the somatic level remains uncertain. In this study, we have investigated the expression levels of KCNB1 and KCNA5 genes encoding ubiquitous Kv2.1 and Kv1.5 potassium channels in gastric and colorectal tumours.

Methods: Gastric and colorectal tumoral and peritumoral tissues were collected to evaluate the expression of KCNB1 and KCNA5 mRNA by quantitative PCR. Moreover, the immunohistochemical staining profile of Kv2.1 and Kv1.5 was assessed on 40 Formalin-Fixed and Paraffin-Embedded (FFPE) gastric carcinoma tissues. Differences in gene expression between tumoral and peritumoral tissues were compared statistically with the Mann-Whitney U test. The association between the clinicopathological features of the GC patients and the expression of both Kv proteins was investigated with χ2 and Fisher's exact tests.

Results: The mRNA fold expression of KCNB1 and KCNA5 genes showed a lower mean in the tumoral tissues (0.06 ± 0.17, 0.006 ± 0.009) compared to peritumoral tissues (0.08 ± 0.16, 0.16 ± 0.48, respectively) without reaching the significance rate (p = 0.861, p = 0.152, respectively). Interestingly, Kv2.1 and Kv1.5 immunostaining was detectable and characterised by a large distribution in peritumoral and tumoral epithelial cells. More interestingly, inflammatory cells were also stained. Surprisingly, Kv2.1 and Kv1.5 staining was undoubtedly and predominantly detected in the cytoplasm compartment of tumour cells. Indeed, the expression of Kv2.1 in tumour cells revealed a significant association with the early gastric cancer clinical stage (p = 0.026).

Conclusion: The data highlight, for the first time, the potential role of Kv1.5 and Kv2.1 in gastrointestinal-related cancers and suggests they may be promising prognostic markers for these tumours.

Keywords: Cancer diagnosis; Colorectal cancer; Gastric cancer; Gene expression; Intracellular localisation; Kv1.5; Kv2.1.

Cone Dystrophy with Supernormal Rod Response (CDSRR) is a rare autosomal recessive disorder leading to severe visual impairment in humans, but little is known about its unique pathophysiology. We have previously shown that CDSRR is caused by mutations in the KCNV2 (Potassium Voltage-Gated Channel Modifier Subfamily V Member 2) gene encoding the Kv8.2 subunit, a modulatory subunit of voltage-gated potassium (Kv) channels. In a recent study, we validated a novel mouse model of Kv8.2 deficiency at a late stage of the disease and showed that it replicates the human electroretinogram (ERG) phenotype. In this current study, we focused our investigation on young adult retinas to look for early markers of disease and evaluate their effect on retinal morphology, electrophysiology and immune response in both the Kv8.2 knockout (KO) mouse and in the Kv2.1 KO mouse, the obligate partner of Kv8.2 in functional retinal Kv channels. By evaluating the severity of retinal dystrophy in these KO models, we demonstrated that retinas of Kv KO mice have significantly higher apoptotic cells, a thinner outer nuclear cell layer and increased activated microglia cells in the subretinal space. Our results indicate that in the murine retina, the loss of Kv8.2 subunits contributes to early cellular and physiological changes leading to retinal dysfunction. These results could have potential implications in the early management of CDSRR despite its relatively nonprogressive nature in humans.

Keywords: CDSRR; KCNB1; KCNV2; cone-rod dystrophy; photoreceptors; retinal degeneration; voltage-gated potassium channels.

In this study, we explored the circular RNA (circRNA) profile in pulmonary arterial hypertension (PAH) patients caused by chronic obstructive pulmonary disease (COPD) and the effects of hsa_circNFXL1_009 on abnormal proliferation, apoptosis, and migration of human pulmonary arterial smooth muscle cells (hPASMCs) driven by hypoxia. Using microarrays, we screened the circRNA profile in whole-blood samples from three pairs of subjects and found 158 dysregulated circRNAs in patients with PAH-COPD. Quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) analysis further validated that hsa_circNFXL1_009 was dramatically downregulated with the highest area under a receiver operating characteristic curve (ROC) in 21 pairs of subjects. Consistently, exposure to hypoxia markedly reduced the hsa_circNFXL1_009 level in cultured hPASMCs. Delivery of exogenous hsa_circNFXL1_009 attenuated hypoxia-induced proliferation, apoptotic resistance, and migration of hPASMCs, as evidenced by immunocytochemistry, 5-ethynyl-2'-deoxyuridine incorporation, wound healing, and a TUNEL (terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling) assay. A luciferase assay showed that hsa_circNFXL1_009 directly sponged hsa-miR-29b-2-5p (miR-29b) and positively regulated the expression of voltage-gated potassium (K⁺) channel subfamily B member 1 (KCNB1) at the mRNA level. Using patch-clamp electrophysiology, we proved that overexpression of hsa_circNFXL1_009 promoted a whole-cell K⁺ current in hPASMCs. Taken together, these studies identify hsa_circNFXL1_009 as a key regulator of PAH, and it may be used as a potential therapeutic target for the treatment of PAH.

Keywords: circular RNA; hypoxia; pulmonary arterial hypertension; remodeling.

Early infantile epileptic encephalopathy 26 (EE26) is a form of epileptic encephalopathy, a heterogeneous group of severe childhood-onset epilepsies characterized by refractory seizures, neurodevelopmental impairment, and poor prognosis. A recent study has shown that the KCNB1 gene mutation is associated with EE26; yet, the exact mechanism remains unclear. In this study, we produced an induced pluripotent stem cell line (iPSC) with a heterozygous variant of the KCNB1 gene (c.990G > T, p.Glu330Asp). Induced iPSCs were generated from peripheral blood mononuclear cells (PBMCs) obtained from a female child aged 6 with KCNB1 gene c. 990G > T and p.Glu330Asp heterozygous mutation.

We report the first trimester three-dimensional ultrasonographic findings in a 13-week-old fetus with complex phenotype and a de novo 4.7 Mb multigene deletion encompassing chromosome region 20q13.13-q13.2 detected by chromosomal microarray. Fetal sonography detected radial-ray anomalies in the form of bilateral absence of thumbs and the left club hand deformity. The presence of single atrioventricular canal instead of the atrial septal defect typical for Holt-Oram syndrome pointed us to rather suspect the SALL4 related diseases. Central nervous system anomaly in the form of enlarged lateral brain ventricles with choroid plexus shifted backwards was not previously reported as a part of SALL4 related disorders. The pregnancy was terminated at 14 + 3 weeks of pregnancy and the autopsy confirmed ultrasonographic findings. Deleted region included 38 genes, where only SALL4, ADNP and KCNB1 heterozygote pathogenic variants were described to be cause of syndromic forms. Radial ray anomalies are common part of clinical picture of SALL4 related disorders. Despite the lack of prenatally described cases, we hypothesized that maldevelopment of lateral brain ventriculomegaly could be very early sonographic sign of disturbed ADNP expression causing Helsmoortel-Van der Aa syndrome, but in some extent also of KCNB1 related early-onset epileptic encephalopathy. Furthermore, the possible dosage-dependent influence of recessive genes located in this region cannot be also excluded. The use of genome-wide technologies enables the detection of subtle chromosomal imbalances and more precise familial genetic counseling regarding actual and future pregnancies.

The function of the inner ear depends on the maintenance of high concentrations of K⁺ ions. The slow-inactivating delayed rectifier Kv2.1/KCNB1 channel works in the inner ear in mammals. The kcnb1 gene is expressed in the otic vesicle of developing zebrafish, suggesting its role in development of the inner ear. In the present study, we found that a Kcnb1 loss-of-function mutation affected development of the inner ear at multiple levels, including otic vesicle expansion, otolith formation, and the proliferation and differentiation of mechanosensory cells. This resulted in defects of kinocilia and stereocilia and abnormal function of the inner ear detected by behavioral assays. The quantitative transcriptional analysis of 75 genes demonstrated that the kcnb1 mutation affected the transcription of genes that are involved in K⁺ metabolism, cell proliferation, cilia development, and intracellular protein trafficking. These results demonstrate a role for Kv2.1/Kcnb1 channels in development of the inner ear in zebrafish.

Keywords: Brain ventricular system; Cilia; Ear; Kinocilium; Kv channels; Otolith formation; Voltage-gated potassium channels; Zebrafish.

Rationale: Developmental epilepsies and encephalopathies (DEEs) are characterized by many severe developmental impairments, which are not well-described. A functional framework could facilitate understanding of their nature and severity and guide the selection instruments to measure improvements in therapeutic trials.

Methods: An online survey administered through several parent-organized foundations utilized accepted functional classifications and questionnaires derived from common instruments to determine levels of mobility, fine motor, communication, and feeding functions. Statistical analyses focused on overall levels of function and across-group comparisons adjusted for age.

Results: From 6/2018 to 2/2020, 252 parents provided information for one or more functional domains. Median age was 7.2 years (interquartile range (IQR): 3.9 to 11.8), and 128 (51%) were females. DEE groups were Dravet syndrome (N = 72), KCNQ2-DEE (N = 80), KCNB1-DEE, (N = 33), Lennox-Gastaut syndrome (LGS; N = 26), electrographic status epilepticus in sleep (ESES; N = 15), and others (N = 26). Overall, functional hand grasp was absent in 48 (20%). Of children ≥2 years old, 60/214 (28%) could not walk independently, 85 (40%) were dependent on someone else for feeding, and 153 (73%) did not effectively communicate with unfamiliar people. Impairments entailing absence or near absence of independent function (profound impairment) were observed in 0, 1, 2, 3, and 4 domains for 58 (25%), 78 (34%), 40 (17%), 33 (14%), and 22 (10%) children, respectively. After adjustment for age, impairment levels varied substantially across DEE group for mobility (p < 0.0001), feeding (p < 0.0001), communication (p < 0.0001), hand grasp (p < 0.0001), and number of profoundly impaired domains (p < 0.0001). Three or four profoundly affected domains were reported in 44% of KCNQ2-DEE participants, followed by LGS (29%), KCNB1-DEE (27%), ESES (7%), and Dravet syndrome (6%).

Conclusions: Many children with DEEs experience severe functional impairments, and few children have typical function. As precision therapies will emphasize nonseizures consequences of DEEs, understanding the nature of abilities and impairments will be critical to selecting appropriate outcome measures in therapeutic trials.

Keywords: Epilepsy; Functional ability; Outcome measures; Precision medicine.

Objective: To explore the association between the phenotype and KCNB1 gene mutation. Method: Clinical information including physical features, laboratory and genetic data of one patient of mental retardation with refractory epilepsy from Department of Pediatrics, Xiangya Hospital in January 2016 was analyzed. This patient was discovered to have KCNB1 gene mutations through whole exome sequencing. Relevant information about KCNB1 gene mutation was searched and collected from Pubmed, CNKI, Human Gene Mutation Database(HGMD) and Online Mendelian Inheritance in Man(OMIM). Searching was done using "KCNB1" as a keyword. Result: A 3.5 years old boy who visited our hospital firstly at the age of 2 years because of development delay came for follow up as he developed seizures.The forms included tonic, clonic seizures and spasm. The condition became more severe 10 months later. Electroencephalogram(EEG) showed high frequency discharge (>85%). He had poor response to multiple anti-epileptic drugs, methylprednisolone and ketogenic diet. At the age of 3, he started to have mental regression. Whole exome-sequencing study (trios) identified a novel heterozygous mutation c. G1136T (p.G379V) in KCNB1, which is not available in the databases mentioned above. This is the first case report of KCNB1 gene mutation in China. Eight cases have been reported so far worldwide and all of them were diagnosed with refractory epilepsy. Those 8 reported cases of encephalopathy were all due to de novo mutation. Conclusion: The main clinical features of patients with KCNB1 mutations include severe to profound intellectual disability, intractable seizures, hypotonia and regression of cognition and motor activity which lead to poor prognosis.

Expression of thrombospondin-4 (TSP-4), a matricellular protein, is increased in the heart tissue of various cardiac disease models. In dorsal root ganglion neurons, TSP-4 inhibits L-type Ca²⁺ channel (LTCC) activity. Although TSP-4 might be related to the electrophysiological properties in heart, it remains to be clarified. The present study aimed to clarify the effects of TSP-4 on action potential (AP), LTCC current (I_CaL) and voltage-dependent K⁺ (Kv) channel current (I_Kv) in rat isolated ventricular myocytes by a patch clamp technique. Ventricular myocytes were isolated from the heart of adult male Wistar rats. The ventricular myocytes were treated with TSP-4 (5 nM) or its vehicle for 4 hr. Then, whole-cell patch clamp technique was performed to measure AP (current-clamp mode) and I_CaL and I_Kv (voltage-clamp mode). The mRNA expression of Kv channels was examined by reverse transcription-polymerase chain reaction. TSP-4 had no effect on the resting membrane potential and peak amplitude of AP. On the other hand, TSP-4 significantly prolonged AP duration (APD) at 50% and 90% repolarization. TSP-4 significantly inhibited the peak amplitudes of I_CaL and I_Kv. TSP-4 had no effect on mRNA expression of Kv channels (Kcna4, Kcna5, Kcnb1, Kcnd2 and Kcnd3). The present study for the first time demonstrated that TSP-4 prolongs APD in rat ventricular myocytes, which is possibly mediated through the suppression of Kv channel activity.

Since the publication of this article the authors have noted that there were two typos that could have caused confusion to the readers:1) References to "integrin alpha chain V" should have been "integrin alpha 5". These appear in the Abstract and the first paragraph of the Results section.2) In the Results section under the header "Integrins activate Fyn tyrosine kinases" and the legend of Figure 6a, "tyr530" should be replaced with "tyr416".3) In the the legend of Figure 6b, "pSrc" with should be replaced with "pFyn".

Voltage-gated potassium (K⁺) channel subfamily B member 1 (KCNB1, Kv2.1) and integrin-α5 form macromolecular complexes-named integrin-α5-KCNB1 complexes (IKCs)-in the human brain, but their function was poorly understood. Here we report that membrane depolarization triggered IKC intracellular signals mediated by small GTPases of the Ras subfamily and protein kinase B (Akt) to advance the development of filopodia and lamellipodia in Chinese hamster ovary cells, stimulate their motility, and enhance neurite outgrowth in mouse neuroblastoma Neuro2a cells. Five KCNB1 mutants (L211P, R312H G379R, G381R, and F416L) linked to severe infancy or early-onset epileptic encephalopathy exhibited markedly defective conduction. However, although L211P, G379R, and G381R normally engaged Ras/Akt and stimulated cell migration, R312H and F416L failed to activate Ras/Akt signaling and did not enhance cell migration. Taken together, these data suggest that IKCs modulate cellular plasticity via Ras and Akt signaling. As such, defective IKCs may cause epilepsy through mechanisms other than dysregulated excitability such as, for example, abnormal neuronal development and resulting synaptic connectivity.-Yu, W., Shin, M. R., Sesti, F. Complexes formed with integrin-α5 and KCNB1 potassium channel wild type or epilepsy-susceptibility variants modulate cellular plasticity via Ras and Akt signaling.

An increasing number of developmental and epileptic encephalopathies have been correlated with variants of ion channel genes, and in particular of potassium channels genes, such as KCNA1, KCNA2, KCNB1, KCNQ2, KCTD7 and KCNT1. Here we report a child with an early severe developmental and epileptic encephalopathy, spastic tetraplegia, opisthotonos attacks. The whole exome sequencing showed the de novo heterozygous variant c.1411G > C (p.Val471Leu) in the KCNC2 gene. Although this is, to our knowledge, the first case of encephalopathy associated with a KCNC2 gene variant, and further confirmatory studies are needed, previous preclinical and clinical evidence seems to suggest that KCNC2 is a new candidate epilepsy gene.

Objective: To determine the prevalence of and identify factors associated with gastrointestinal (GI) symptoms among patients with channelopathy-associated developmental and epileptic encephalopathy (DEE).

Study design: Parents of 168 patients with DEEs linked to SCN1A (N=59), KCNB1 (N=31), or KCNQ2 (N=78) completed online CLIRINX surveys about their children's GI symptoms. Analysis examined prevalence, frequency, and severity of GI symptoms, as well as DEE type, functional mobility, feeding difficulties, ketogenic diet, anti-seizure medication, autism spectrum disorder (ASD), and seizures. Statistical analyses included chi-square tests, Wilcoxon rank-sum analyses, and multiple logistic regression.

Results: Patients (median age of 6.3 years; 92 [55%] females) included 59 (44%) with SCN1A-DEE, 31 (35%) with KCNB1-DEE, and 78 (71%) with KCNQ2-DEE. GI symptoms were reported in 92/168 (55%) patients among whom 63/86 (73%) reported daily or weekly symptoms, 29/92 (32%) had frequent or serious discomfort, and 13/91 (14%) had appetite disturbances as a result. After adjustment for DEE type, current use of ketogenic diet (6% reported), and gastrostomy tube (13% reported) were both associated with GI symptoms in a statistically, but not clinically significant manner (P < .05). Patient age, functional mobility, feeding difficulties, ASD, and seizures were not clearly associated with GI symptoms. Overall, no individual anti-seizure medication was significantly associated with GI symptoms.

Conclusions: GI symptoms are common and frequently severe in DEE patients.

Keywords: Constipation; gastrointestinal dysmotility; voltage-gated potassium channel; voltage-gated sodium channel.

Objectives: To determine the suitability of the Aberrant Behavior Checklist (ABC)-a common measure used in clinical trials for treatment of challenging behaviors of autism-as an outcome measure for pharmacological and behavioral interventions for young people with Developmental and Epileptic Encephalopathies (DEEs).

Methods: We assessed score profiles on the ABC in a sample of 122 young people with DEEs, including Dravet and Lennox-Gastaut syndromes, and KCNQ2- SCN2A-, and KCNB1-associated disorders. Then we examined its internal structure using item cluster analysis. We used both unrestricted item cluster analysis to determine the number of item clusters that maximize reliability and restricted analyses in which we pre-specified models with 5-, 6-, and 7-clusters, to examine consistency with previous factor analytic studies. We also conducted validity analysis on the various scoring methods with age, sex, and autism spectrum screening measure scores.

Results: Unrestricted item cluster analysis suggested that three clusters maximized reliability of ABC scores. These broadly represented other-directed behaviors (i.e., "externalizing"), self-directed behaviors (i.e., "internalizing"), and inappropriate speech. Restricted models separated item clusters for stereotypy from other self-directed problem behaviors, and self-injurious behaviors from the other externalizing behaviors. Validity analysis also supported these structures. Overall, all scores were low, and less than 20% of DEE participants had symptoms severe enough to qualify for most randomized trials of behavioral therapies.

Significance: These results are broadly consistent with the extant ABC scoring algorithms. They suggest a high internal consistency reliability, which may support the use of the ABC in future clinical trials in patients with DEEs who exhibit the behaviors assessed by the ABC. Alternatively, concerns about overall low scores raise cautions about using the ABC as a measure of behavior in unselected populations with DEE.

Keywords: Aberrant Behavior Checklist; Children; Developmental and Epileptic Encephalopathies; Intellectual disability; Item cluster analysis; Trial readiness.