Case Report: Tuberous sclerosis complex-associated hemihypertrophy successfully treated with mTOR inhibitor sirolimus.

Tuberous sclerosis complex (TSC) is an autosomal dominant disorder caused by a mutation in either of the two tumor suppressor genes, TSC1 and TSC2. Due to dysregulated activity of the mammalian target of rapamycin (mTOR) pathway, hamartomas or benign tumors frequently occur in many organs and are often treated with mTOR inhibitors. Hemihypertrophy is a rare complication of TSC. Although not being a tumor, progressive overgrowth of the affected limb may cause cosmetic and functional problems, for which the efficacy of mTOR inhibitors has not been reported previously. We herein report a case of TSC-associated hemihypertrophy. In this case, genetic studies revealed TSC1 loss of heterozygosity as the cause of hemihypertrophy. Clinically, pharmacological treatment with an mTOR inhibitor sirolimus successfully ameliorated cosmetic and functional problems with no intolerable adverse effects.

Clinical characteristics of SARS-CoV-2-associated encephalopathy in children: Nationwide epidemiological study.

OBJECTIVE: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sometimes triggers acute encephalopathy as a serious neurological complication in children. We previously reported the clinico-radiological findings of SARS-CoV-2-associated encephalopathy. The advent of the SARS-CoV-2 omicron variant led to a marked increase in pediatric patients with coronavirus disease 2019 (COVID-19); however, epidemiological changes with acute encephalopathy according to the emergence of SARS-CoV-2 have not yet been documented. Therefore, the present study investigated epidemiological differences in SARS-CoV-2-associated encephalopathy during the BA.1/BA.2 and BA.5 predominant periods and also between SARS-CoV-2-associated and non-SARS-CoV-2-associated encephalopathy. METHODS: We conducted a nationwide survey of SARS-CoV-2-associated encephalopathy in Japanese children between June and November 2022. We compared the present results during the BA.5 predominant period and previous findings during the BA.1/BA.2 predominant period. We also compared the clinico-radiological syndromes of encephalopathy between SARS-CoV-2-associated and non-SARS-CoV-2-associated encephalopathy. RESULTS: Although many patients with SARS-CoV-2-associated encephalopathy in the BA.5 predominant period had seizures as their initial symptoms, no significant differences were observed in the clinical features. Patients with SARS-CoV-2-associated encephalopathy had worse outcomes than those with non-SARS-CoV-2-associated encephalopathy (p-value = 0.003). Among 103 patients with SARS-CoV-2-associated encephalopathy, 14 (13.6%) had severe types of acute encephalopathy, namely, encephalopathy with acute fulminant cerebral edema (AFCE) and hemorrhagic shock and encephalopathy syndrome (HSES). Also, 28 (27.2%) patients with SARS-CoV-2-associated encephalopathy had poor outcome: severe neurological sequelae or death. Ninety-five patients (92.2%) were not vaccinated against SARS-CoV-2. CONCLUSIONS: In SARS-CoV-2-associated encephalopathy, high percentages of AFCE and HSES can result in poor outcomes.

Association of IL6 and IL10 gene promotor polymorphisms with susceptibility to acute necrotizing encephalopathy.

Objective: Acute necrotizing encephalopathy (ANE) is a severe complication of infectious diseases affecting the brain and systemic organs. The main pathogenesis is cytokine storm, in which interleukin-6 (IL-6) and interleukin-10 (IL-10) are candidates for key cytokines. To further elucidate their roles in the etiology and pathogenesis of ANE, we studied polymorphisms in the promotor regions of the IL6 and IL10 genes by genetic and functional analyses. Methods: We first conducted a case-control association study of four IL6 and three IL10 polymorphisms. We genotyped 31 Japanese ANE cases and compared the results with those of approximately 200 Japanese controls. For the two polymorphisms showing a possible association, we next studied whether the polymorphisms alter the production of IL-6 or IL-10 by lymphoblasts upon phorbol 12-myristate 13-acetate (PMA) stimulation. Results: The frequencies of IL6 rs1800796G allele and IL10 rs1800871/rs1800872 CC/CC diplotype were significantly higher in ANE cases than in controls. The IL10 CC/CC diplotype was associated with low IL-10 production, whereas the IL6 GG genotype was not associated with IL-6 production. Conclusion: IL10 rs1800871/rs1800872 CC/CC diplotype may predispose Japanese children to ANE by altering IL-10 production in the early phase of infection. Etio-pathogenetic significance of IL6 rs1800796G remains to be elucidated.

Clinical Practice Guidelines for tuberous sclerosis complex-associated renal angiomyolipoma by the Japanese Urological Association: Summary of the update.

New clinical issues have been raised through an interval of 7 years from the previous version (2016). In this study, we update the "Clinical Practice Guidelines for tuberous sclerosis complex-associated renal angiomyolipoma" as a 2023 version under guidance by the Japanese Urological Association. The present guidelines were cooperatively prepared by the Japanese Urological Association and Japanese Society of Tuberous Sclerosis Complex; committee members belonging to one of the two societies or specializing in the treatment of this disease were selected to prepare the guidelines in accordance with the "Guidance for preparing treatment guidelines" published by Minds (2020 version). The "Introduction" consisted of four sections, "Background Questions (BQ)" consisted of four sections, "Clinical Questions (CQ)" consisted of three sections, and "Future Questions (FQ)" consisted of three sections (total: 14 sections). Concerning CQ, an agreement was confirmed through voting by the committee members based on the direction and strength of recommendation, accuracy of evidence, and recommendation comments. The present guidelines were updated based on the current evidence. We hope that the guidelines will provide guiding principles for the treatment of tuberous sclerosis complex-associated renal angiomyolipoma to many urologists, becoming a foundation for subsequent updating.

Severe pediatric acute encephalopathy syndromes related to SARS-CoV-2.

Background and objectives: To clarify whether severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection cause acute encephalopathy in children and which are the most common syndromes that cause them and what are the outcomes. Methods: A nationwide web-based survey among all members of the Japanese Society of Child Neurology to identify pediatric patients aged < 18 years who developed acute encephalopathy in Japan between 1 January 2020 and 31 May 2022 associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection confirmed by polymerase chain reaction or antigen tests using pharyngeal swabs. Acute encephalopathy was defined as acute onset of impaired consciousness lasting > 24 h or an altered mental state; neurological symptoms arising within 2 weeks of onset of COVID-19 or multisystem inflammatory syndrome in children (MIS-C)/pediatric inflammatory multisystem syndrome (PIMS); evidence of SARS-CoV-2 infection; and reasonable exclusion of other diseases. Patients were divided into the known clinico-radiological acute encephalopathy syndrome group and unexplained or unclassifiable acute encephalopathy group. Outcomes were assessed by pediatric cerebral performance category (PCPC) score at hospital discharge. Results: Of the 3,802 society members, 217 representing institutions responded, and 39 patients with suspected acute encephalopathy were reported, of which 31 met inclusion criteria. Of these patients, 14 were diagnosed with known clinico-radiological acute encephalopathy syndromes, with acute encephalopathy with biphasic seizures and late reduced diffusion (five patients) being the most common. Five developed acute encephalopathy associated with MIS-C/PIMS. Among 31 patients, 9 (29.0%) had severe sequelae or died (PCPC ≥ 4). Two of three patients with encephalopathy with acute fulminant cerebral edema and two with hemorrhagic shock and encephalopathy syndrome died. The PCPC scores were higher in the known clinico-radiological acute encephalopathy syndrome group than in the unexplained or unclassifiable acute encephalopathy group (P < 0.01). Discussion: Acute encephalopathy related to SARS-CoV-2 infection was demonstrated to be more severe than that caused by other viruses in Japan. Acute encephalopathy syndromes characterized by specific neuroradiological findings was associated with poor clinical outcomes.

Genetic and environmental risk factors of acute infection-triggered encephalopathy.

Acute encephalopathy is a constellation of syndromes in which immune response, metabolism and neuronal excitation are affected in a variable fashion. Most of the syndromes are complex disorders, caused or aggravated by multiple, genetic and environmental risk factors. Environmental factors include pathogenic microorganisms of the antecedent infection such as influenza virus, human herpesvirus-6 and enterohemorrhagic Escherichia coli, and drugs such as non-steroidal anti-inflammatory drugs, valproate and theophylline. Genetic factors include mutations such as rare variants of the SCN1A and RANBP2 genes, and polymorphisms such as thermolabile CPT2 variants and HLA genotypes. By altering immune response, metabolism or neuronal excitation, these factors complicate the pathologic process. On the other hand, some of them could provide promising targets to prevent or treat acute encephalopathy.

Tsc2 mutation rather than Tsc1 mutation dominantly causes a social deficit in a mouse model of tuberous sclerosis complex.

BACKGROUND: Tuberous sclerosis complex (TSC) is an autosomal dominant disorder that is associated with neurological symptoms, including autism spectrum disorder. Tuberous sclerosis complex is caused by pathogenic germline mutations of either the TSC1 or TSC2 gene, but somatic mutations were identified in both genes, and the combined effects of TSC1 and TSC2 mutations have been unknown. METHODS: The present study investigated social behaviors by the social interaction test and three-chambered sociability tests, effects of rapamycin treatment, and gene expression profiles with a gene expression microarray in Tsc1 and Tsc2 double heterozygous mutant (TscD+/-) mice. RESULTS: TscD+/- mice exhibited impairments in social behaviors, and the severity of impairments was similar to Tsc2+/- mice rather than Tsc1+/- mice. Impairments in social behaviors were rescued by rapamycin treatment in all mutant mice. Gene expression profiles in the brain were greatly altered in TscD+/- mice more than in Tsc1+/- and Tsc2+/- mice. The gene expression changes compared with wild type (WT) mice were similar between TscD+/- and Tsc2+/- mice, and the overlapping genes whose expression was altered in mutant mice compared with WT mice were enriched in the neoplasm- and inflammation-related canonical pathways. The "signal transducer and activator of transcription 3, interferon regulatory factor 1, interferon regulatory factor 4, interleukin-2R α chain, and interferon-γ" signaling pathway, which is initiated from signal transducer and activator of transcription 4 and PDZ and LIM domain protein 2, was associated with impairments in social behaviors in all mutant mice. LIMITATIONS: It is unclear whether the signaling pathway also plays a critical role in autism spectrum disorders not caused by Tsc1 and Tsc2 mutations. CONCLUSIONS: These findings suggest that TSC1 and TSC2 double mutations cause autistic behaviors similarly to TSC2 mutations, although significant changes in gene expression were attributable to the double mutations. These findings contribute to the knowledge of genotype-phenotype correlations in TSC and suggest that mutations in both the TSC1 and TSC2 genes act in concert to cause neurological symptoms, including autism spectrum disorder.

Changes in the treatment of pediatric acute encephalopathy in Japan between 2015 and 2021: A national questionnaire-based survey.

BACKGROUND: Although acute encephalopathy (AE) is the most serious disorder associated with a viral infection in childhood and often causes death or neurological sequelae, standard treatments have not been established. In 2016, the Japanese Society of Child Neurology published the "Guidelines for the Diagnosis and Treatment of Acute Encephalopathy in Childhood 2016" (AE GL 2016). We conducted a questionnaire survey to evaluate the status of the treatment of pediatric AE in 2021 and the changes in treatment before and after the publication of the AE GL 2016. METHODS: In October 2021, questionnaires were mailed via the web to members of two mailing lists who were involved in the practice of pediatric neurological disorders. RESULTS: Most Japanese physicians (98 %) engaged in the treatment of pediatric AE used the AE GL 2016 as a clinical reference. From 2015 to 2021, the number of institutions that implemented targeted temperature management (TTM), vitamin administration, and continuous electroencephalographic monitoring increased significantly. Regarding the targeted temperature for TTM, the proportion of patients who were treated with normothermia (36.0-37.0 °C) increased from 2015 (55 %) to 2021 (79 %). The use of corticosteroids in patients with AE caused by a cytokine storm, which is recommended in the AE GL 2016, had already been implemented in most institutions by 2015. CONCLUSION: The AE GL 2016 could be used to disseminate the knowledge accumulated to date. Evidence of the efficacy and proper indication criteria for the treatment of AE is insufficient and must be further accumulated.

Prediction and assessment of acute encephalopathy syndromes immediately after febrile status epilepticus.

OBJECTIVE: This study aimed to predict occurrence of acute encephalopathy syndromes (AES) immediately after febrile status epilepticus in children and to explore the usefulness of electroencephalogram (EEG) in the early diagnosis of AES. METHODS: We reviewed data from 120 children who had febrile status epilepticus lasting >30 min and were admitted to our hospital between 2012 and 2019. AES with reduced diffusion on brain magnetic resonance imaging was diagnosed in 11 of these patients. EEG and serum cytokines were analyzed in AES patients. Clinical symptoms and laboratory data were compared between AES and non-AES patients. Logistic regression analysis was used to identify early predictors of AES. RESULTS: Multivariate logistic regression identified serum creatinine as a risk factor for developing AES. A scoring model to predict AES in the post-ictal phase that included serum creatinine, sodium, aspartate aminotransferase, and glucose was developed, and a score of 2 or more predicted AES with sensitivity of 90.9% and specificity of 71.6%. Post-ictus EEG revealed non-convulsive status epilepticus in four of the seven AES patients. CONCLUSION: Children with febrile status epilepticus may be at risk of developing severe AES with reduced diffusion. Post-ictus EEG and laboratory data can predict the occurrence of severe AES.

Comparison of mortality and survival without major morbidities of very preterm infants with very low birth weight from Japan and Brazil / Comparação entre mortalidade e sobrevida sem morbidades importantes dos recém-nascidos prematuros de muito baixo peso entre o Japão e o Brasil

Abstract Objective: This study was carried out to understand the disparities in mortality and survival without major morbidities among very premature and very low birth weight infants between participating Neonatal Intensive Care Units (NICUs) from the Brazilian Network on Neonatal Research (RBPN) and the Neonatal Research Network of Japan (NRNJ). Methods: Secondary data analysis of surveys by the RBPN and NRNJ was performed. The surveys were conducted in 2014 and 2015 and included 187 NICUs. Primary outcome was mortality or survival without any major morbidity. Logistic regression analysis adjustment for confounding factors was used. Results: The study population consisted of 6,406 infants from the NRNJ and 2,319 from the RBPN. Controlling for various confounders, infants from RBPN had 9.06 times higher adjusted odds of mortality (95%CI 7.30-11.29), and lower odds of survival without major morbidities (AOR 0.36; 95%CI 0.32-0.41) compared with those from the NRNJ. Factors associated with higher odds of mortality among Brazilian NICUs included: Air Leak Syndrome (AOR 4.73; 95%CI 1.26-15.27), Necrotizing Enterocolitis (AOR 3.25; 95%CI 1.38-7.26), and Late Onset Sepsis (LOS) (AOR 4.86; 95%CI 2.25-10.97). Conclusions: Very premature and very low birth weight infants from Brazil had significantly higher odds for mortality and lower odds for survival without major morbidities in comparison to those from Japan. Additionally, we identified the factors that increased the odds of in-hospital neonatal death in Brazil, most of which was related to LOS.

RESUMO Objetivo: Este estudo foi realizado para compreender as disparidades na mortalidade e sobrevivência sem as principais morbidades entre recém-nascidos muito prematuros e de muito baixo peso entre Unidades de Terapia Intensiva Neonatal (UTINs) participantes da Rede Brasileira de Pesquisas Neonatais (RBPN) e Rede de Pesquisa Neonatal do Japão (NRNJ). Métodos: Foi realizada uma análise dos dados secundários dos bancos de dados da RBPN e da NRNJ. As pesquisas foram realizadas em 2014 e 2015 e incluíram 187 UTINs. O desfecho primário foi mortalidade ou sobrevida sem qualquer morbidade importante. Utilizou-se a análise de regressão logística com ajuste para os fatores de confusão. Resultados: A população do estudo foi composta por 6.406 recém-nascidos do NRNJ e 2.319 do RBPN. Ajustando para diversos fatores de confusão, os prematuros da RBPN tiveram 9,06 vezes maiores chances de mortalidade (IC95% 7,30-11,29) e menores chances de sobrevivência sem morbidades importantes (AOR 0,36; IC95% 0,32-0,41) em comparação com os da NRNJ. Fatores associados a maiores chances de mortalidade entre as UTINs brasileiras incluíram: síndrome de escape de ar (AOR 4,73; IC95% 1,26-15,27), enterocolite necrosante (AOR 3,25; IC95% 1,38-7,26) e sepse de início tardio (AOR 4,86; IC95% 2,25-10,97). Conclusões: Os recém-nascidos muito prematuros e de muito baixo peso do Brasil apresentaram chances significativamente maiores de mortalidade e menores chances de sobrevivência sem as principais morbidades em comparação aos do Japão. Além disso, identificamos os fatores que aumentam as chances da morte neonatal no Brasil, sendo a maioria relacionada à sepse tardia.

Comparison of mortality and survival without major morbidities of very preterm infants with very low birth weight from Japan and Brazil.

OBJECTIVE: This study was carried out to understand the disparities in mortality and survival without major morbidities among very premature and very low birth weight infants between participating Neonatal Intensive Care Units (NICUs) from the Brazilian Network on Neonatal Research (RBPN) and the Neonatal Research Network of Japan (NRNJ). METHODS: Secondary data analysis of surveys by the RBPN and NRNJ was performed. The surveys were conducted in 2014 and 2015 and included 187 NICUs. Primary outcome was mortality or survival without any major morbidity. Logistic regression analysis adjustment for confounding factors was used. RESULTS: The study population consisted of 6,406 infants from the NRNJ and 2,319 from the RBPN. Controlling for various confounders, infants from RBPN had 9.06 times higher adjusted odds of mortality (95%CI 7.30-11.29), and lower odds of survival without major morbidities (AOR 0.36; 95%CI 0.32-0.41) compared with those from the NRNJ. Factors associated with higher odds of mortality among Brazilian NICUs included: Air Leak Syndrome (AOR 4.73; 95%CI 1.26-15.27), Necrotizing Enterocolitis (AOR 3.25; 95%CI 1.38-7.26), and Late Onset Sepsis (LOS) (AOR 4.86; 95%CI 2.25-10.97). CONCLUSIONS: Very premature and very low birth weight infants from Brazil had significantly higher odds for mortality and lower odds for survival without major morbidities in comparison to those from Japan. Additionally, we identified the factors that increased the odds of in-hospital neonatal death in Brazil, most of which was related to LOS.

Association of IL-1B rs16944 Polymorphism With Acute Encephalopathy With Biphasic Seizures and Late Reduced Diffusion Is Opposite to That of Febrile Seizures.

Objective: Acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) is a severe neurologic complication of febrile infectious diseases in children. At the onset, AESD is clinically manifested as febrile status epilepticus. Subsequent damage to the cerebral cortex is ascribed to neurotoxicity. The incidence of AESD is remarkably high in Japan, suggesting the involvement of genetic factors. The expression of interleukin 1 beta (IL-1ß), a member of the cytokine family involved in the inflammatory response, is reportedly associated with rs16944, a polymorphism in the upstream region of the IL-1B gene, being higher in TT genotype. Previous association studies of rs16944 with febrile seizures (FS) have demonstrated a significant excess in the TT vs. CC + CT genotype in the Asian population. Here, we conducted a case-control association study of rs16944 in AESD. Methods: We genotyped rs16944 by Sanger sequencing on 283 patients with AESD. As controls, we used genotyping data of 104 Japanese individuals obtained from the 1,000 Genomes Project. Then, we performed a case-control association study using the chi-square test. Results: The ratio of individuals with TT vs. those with CC+CT genotype was significantly lower in AESD than in the controls [p-value 0.021, Odds Ratio (OR) 0.52]. This finding was opposite to that of a previously reported FS. Conclusion: The AESD has a genetic background distinct from FS and is not a severe type of FS.

Longitudinal Trends of Prevalence of Neutralizing Antibody against Human Cytomegalovirus over the Past 30 Years in Japanese Women.

Neutralizing antibodies (NAbs) to human cytomegalovirus (HCMV) are associated with the risk of transplacental HCMV infection of the fetus in pregnant women. The IgG-positivity rate to HCMV determined by enzyme immunoassay (EIA) or indirect immunofluorescence assay has decreased from approximately 100% to 70% over the past 30 years in Japan. We tested serum samples from 630 Japanese women aged 20-49 years whose blood samples were obtained between 1980 and 2015. IgG titer was measured using an EIA-based assay. HCMV-NAb titer was measured using a neutralization test assay with an HCMV isolate on human retinal epithelial cells. Longitudinal transitions in HCMV-NAb prevalence were clarified. The prevalence of HCMV-EIA-IgG, and HCMV-NAb at a titer of 16-fold, and HCMV-NAb at a titer of 100-fold, changed from 96.7% to 78.9%, 93.3% to 85.6%, and 35.5% to 41.1%, respectively, between 1980-1990 and 2010-2015. Prevalence of HCMV-NAb at a titer of 16-fold decreased by 7.7%, whereas that at a titer of 100-fold increased by 5.6%. A high titer of HCMV-NAb in pregnant women is expected to reduce the risk of intrauterine HCMV transmission from the mother to the fetus. The association between the risk of congenital HCMV infection and the prevalence of HCMV-NAb remains to be addressed.

Protective association of HLA-DPB1*04:01:01 with acute encephalopathy with biphasic seizures and late reduced diffusion identified by HLA imputation.

Acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) is a severe syndrome of acute encephalopathy that affects infants and young children. AESD is a polygenic disorder preceded by common viral infections with high fever. We conducted an association study of human leukocyte antigen (HLA) regions with AESD using HLA imputation. SNP genotyping was performed on 254 Japanese patients with AESD and 799 healthy controls. We conducted 3-field HLA imputation for 14 HLA genes based on Japanese-specific references using data from our previous genome-wide association study. After quality control, 208 patients and 737 controls were included in the analysis of HLA alleles. We then compared the carrier frequencies of HLA alleles and haplotypes between the patients and controls. HLA-DPB1*04:01:01 showed a significant association with AESD, exerting a protective effect against the disease (p = 0.0053, pcorrected = 0.042, odds ratio = 0.43, 95% confidence interval = 0.21-0.80). The allele frequency of HLA-DPB1*04:01:01 was lower in East Asians than in Caucasians, which may partially account for the higher incidence of AESD in the Japanese population. The present results demonstrate the importance of fine-mapping of the HLA region to investigate disease susceptibilities and elucidate the pathogenesis of AESD.

[Perspective on transition from pediatric to adult health care for patients with neurological disease: current situation and issues].

An improvement in efficacy treatment and development of the social support system has led to many patients with neurological disease being able to reach adulthood. Therefore health care for life from pediatrics to adulthood has become necessary. The Special Committee for Measures Against Transition from Pediatric to Adult Health Care of the Japanese Society of Neurology officially started to examine the current situation and issues of transition from pediatric to adult health care in July 2020. Pediatric neurologists and adult neurologists have an awareness of this issue of constructing a better transition from pediatric to adult health care. However, there are some tasks that need to be resolved in the medical system. We intend to improve the understanding of transition and assessment of medical service fees for transition in cooperation with the Japanese Society of Neurology and the Japanese Society of Child Neurology.

Virulence of Herpes Simplex Virus 1 Harboring a UAG Stop Codon between the First and Second Initiation Codon in the Thymidine Kinase Gene.

Herpes simplex virus 1 (HSV-1)-TK (8UAG) expresses a truncated thymidine kinase (TK) translated from the second initiation codon due to a stop codon (UAG) at the 8th position (counted from the first initiation codon). Here, we showed that the sensitivity of HSV-1-TK (8UAG) to acyclovir (ACV) is similar to that of the control HSV-1 wild-type (WT), which expresses an intact TK protein. However, HSV-1-TK (44UAG), which expresses a truncated TK due to a UAG codon at position 44, showed lower sensitivity to ACV. A mouse infection model was used to compare the virulence of HSV-1-TK (8UAG) and HSV-1-TK (44UAG) to that of HSV-1 WT. The 50% lethal dose (LD50) for HSV-1-TK (44UAG) was 7.8-fold higher than that for HSV-1-TK (8UAG), whereas the LD50 for HSV-1-TK (8UAG) was the same as that for the parental HSV-1 WT. There were no statistically significant differences among HSV-1-TK (44UAG), HSV-1-TK (8UAG), and HSV-1 WT with respect to replication capacity and viral TK mRNA expression in the mouse brain. Thus, the virulence of HSV-1 expressing the truncated viral TK translated from the second initiation codon might depend on the position of the UAG stop codon.

GWAS identifies candidate susceptibility loci and microRNA biomarkers for acute encephalopathy with biphasic seizures and late reduced diffusion.

Acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) is a severe encephalopathy preceded by viral infections with high fever. AESD is a multifactorial disease, however, few disease susceptibility genes have previously been identified. Here, we conducted a genome-wide association study (GWAS) and assessed functional variants in non-coding regions to study genetic susceptibility in AESD using 254 Japanese children with AESD and 799 adult healthy controls. We also performed a microRNA enrichment analysis using GWAS statistics to search for candidate biomarkers in AESD. The variant with the lowest p-value, rs1850440, was located in the intron of serine/threonine kinase 39 gene (STK39) on chromosome 2q24.3 (p = 2.44 × 10-7, odds ratio = 1.71). The minor allele T of rs1850440 correlated with the stronger expression of STK39 in peripheral blood. This variant possessed enhancer histone modification marks in STK39, the encoded protein of which activates the p38 mitogen-activated protein kinase (MAPK) pathway. In the replication study, the odds ratios of three SNPs, including rs1850440, showed the same direction of association with that in the discovery stage GWAS. One of the candidate microRNAs identified by the microRNA enrichment analysis was associated with inflammatory responses regulated by the MAPK pathway. This study identified STK39 as a novel susceptibility locus of AESD, found microRNAs as potential biomarkers, and implicated immune responses and the MAPK cascade in its pathogenesis.

RANBP2 mutation causing autosomal dominant acute necrotizing encephalopathy attenuates its interaction with COX11.

PURPOSE: Autosomal dominant acute necrotizing encephalopathy (ADANE) is caused by missense mutations in the gene encoding Ran-binding protein 2 (RANBP2), a nuclear pore protein regulating mitochondrial localization and function. Previous studies have found that RANBP2 binds to COX11 and suppresses its inhibitory activity over hexokinase1. To further elucidate mitochondrial dysfunction in ADANE, we analyzed the interaction between mutated RANBP2 and COX11. METHODS: We extracted cDNA from a patient and constructed pGEX wild-type or mutant-type vectors including RANBP2 c.1754C>T, the commonest variant in ADANE. We transformed E. coli competent cells with the vectors and had them express GST-RANBP2 recombinant protein, and conducted a pull-down assay of RANBP2 and COX11. RESULTS: The amount of COX11 bound to mutated RANBP2 was significantly smaller than that bound to the wild-type RANBP2. CONCLUSION: Mutated RANBP2 had an attenuated binding ability to COX11. Whether this change indeed decreases ATP production remains to be further explored.

Brain Symptoms of Tuberous Sclerosis Complex: Pathogenesis and Treatment.

The mammalian target of the rapamycin (mTOR) system plays multiple, important roles in the brain, regulating both morphology, such as cellular size, shape, and position, and function, such as learning, memory, and social interaction. Tuberous sclerosis complex (TSC) is a congenital disorder caused by a defective suppressor of the mTOR system, the TSC1/TSC2 complex. Almost all brain symptoms of TSC are manifestations of an excessive activity of the mTOR system. Many children with TSC are afflicted by intractable epilepsy, intellectual disability, and/or autism. In the brains of infants with TSC, a vicious cycle of epileptic encephalopathy is formed by mTOR hyperactivity, abnormal synaptic structure/function, and excessive epileptic discharges, further worsening epilepsy and intellectual/behavioral disorders. Molecular target therapy with mTOR inhibitors has recently been proved to be efficacious for epilepsy in human TSC patients, and for autism in TSC model mice, indicating the possibility for pharmacological treatment of developmental synaptic disorders.