Two ovarian candidate enhancers, identified by time series enhancer RNA analyses, harbor rare genetic variations identified in ovarian insufficiency.

The genetic regulation of ovarian development remains largely unclear. Indeed, in most cases of impaired ovarian development-such as 46,XX disorders of sex development (DSD) without SRY, and premature ovarian insufficiency (POI)-the genetic causes have not been identified, and the vast majority of disease-associated sequence variants could lie within non-coding regulatory sequences. In this study, we aimed to identify enhancers of five ovarian genes known to play key roles in early ovarian development, basing our analysis on the expression of enhancer derived transcripts (eRNAs), which are considered to characterize active enhancers. Temporal expression profile changes in mouse WT1-positive ovarian cells were obtained from cap analysis of gene expression at E13.5, E16.5 and P0. We compared the chronological expression profiles of ovarian-specific eRNA with expression profiles for each of the ovarian-specific genes, yielding two candidate sequences for enhancers of Wnt4 and Rspo1. Both sequences are conserved between mouse and human, and we confirmed their enhancer activities using transient expression assays in murine granulosa cells. Furthermore, by sequencing the region in patients with impaired ovarian development in 24 patients, such as POI, gonadal dysgenesis and 46,XX DSD, we identified rare single nucleotide variants in both sequences. Our results demonstrate that combined analysis of the temporal expression profiles of eRNA and mRNA of target genes presents a powerful tool for locating cis-element enhancers, and a means of identifying disease-associated sequence variants that lie within non-coding regulatory sequences, thus advancing an important unmet need in forward human genetics.

Marked clinical heterogeneity in congenital hyperinsulinism due to a novel homozygous ABCC8 mutation.

BACKGROUND: The most severe forms of congenital hyperinsulinism (CHI) are caused by inactivating mutations of two KATP channel genes, KCNJ11 and ABCC8. Unresponsiveness to diazoxide and need for subtotal pancreatectomy can usually be predicted by genetic form, particularly biallelic mutations in KATP channel genes. A few reports indicated marked clinical heterogeneity in siblings with identical biallelic mutations in ABCC8. The clinical heterogeneity in biallelic KATP CHI was speculated to be caused by epigenetic and environmental factors or related to differences in splicing factor machinery. OBJECTIVE: To elucidate the clinical pathophysiology, especially heterogeneity, among three cases with CHI caused by a homogenous novel mutation. PATIENTS AND METHODS: We report a case series that includes two siblings and one unrelated individual with CHI caused by a homogenous 1-bp deletion around the splice acceptor site at the exon 35 mutation of ABCC8, which exhibited markedly distinct phenotypes. To assess the effect of the mutation on splicing, we performed digital droplet polymerase chain reaction (ddPCR) on normal pancreas tissue and a patient's lymphocytes. RESULTS: ddPCR of ABCC8 cDNA revealed that expression of exon 35 and its upstream and downstream regions did not differ. These data suggested that clinical heterogeneity may not be caused by differences in splicing factor machinery. CONCLUSION: The phenotypic variation in homozygotes could not be explained by splicing abnormalities. Though early genetic diagnosis of KATP CHI could contribute to selecting appropriate therapeutic options, more deliberate selection of therapeutic options in diffuse CHI due to biallelic ABCC8 mutations may be required.

The progression of salt-wasting and the body weight change during the first 2 weeks of life in classical 21-hydroxylase deficiency patients.

BACKGROUND: One of the major purposes of newborn screening for 21-hydroxylase deficiency (21OHD) is preventing life-threatening adrenal crisis. However, the details of adrenal crisis in newborns are not precisely documented. AIM: We aimed to clarify the clinical details of salt-wasting in newborn 21OHD patients. METHODS: Based on the follow-up survey of the screening in Tokyo from 1989 to 2017, we retrospectively analysed the conditions of classical 21OHD neonates before the initiation of therapy. RESULTS: One hundred classical 21OHD patients (55 male, 45 female) were analysed. The age at the first hospital visit was 0-20 days with sex difference (male: 9.0 ± 3.5 days; female: 6.2 ± 3.9 days). Thirty-seven (37.4%) patients exhibited severe salt-wasting (SSW), that is, Na < 130 mEq/L, K > 7 mEq/L or Na/K ratio < 20; except for one case, SSW developed in or after the second week of life. The serum concentrations of Na, K and Na/K were linearly correlated with age in days (R2  = .38, .25, and .34 respectively), suggesting that the risk of SSW increases linearly without a threshold. The age at which the regression lines reached Na < 130 mEq/L, K > 7 mEq/L and Na/K < 20 was approximately coincided, 11.1, 12.3 and 11.2 days, respectively. All SSW patients exhibited decreased body weight from birth in their second week of life. CONCLUSION: Our data revealed that the risk of developing SSW increases during the second week of life without a threshold, and for preventing SSW, early intervention, ideally during first week of life, is desirable. An increased body weight in the second week of life indicates the absence of SSW.

A postzygotic KRAS mutation in a patient with Schimmelpenning syndrome presenting with lipomatosis, renovascular hypertension, and diabetes mellitus.

Schimmelpenning syndrome is a rare neurocutaneous disorder categorized as a mosaic RASopathy due to postzygotic HRAS or KRAS mutations. We report a 6-year-old girl diagnosed with Schimmelpenning syndrome due to a postzygotic KRAS G12D mutation. The patient had three atypical symptoms of Schimmelpenning syndrome: renovascular hypertension, congenital lipomatosis, and diabetes mellitus. The first two symptoms may overlap with phenotypes of other neurocutaneous syndromes or congenital lipomatous overgrowth syndrome due to mosaic RASopathies or other somatic mosaic mutations. We propose that impaired glucose tolerance was caused by KRAS mutation and a novel clinical phenotype of Schimmelpenning syndrome. Our study indicated that clinical diagnosis of Schimmelpenning syndrome or related conditions should be reorganized with genetic diagnosis of postzygotic mutation. Moreover, further accumulation of genetically proven cases with mosaic RASopathies should be used to more accurately characterize phenotypic presentations of this syndrome and develop a future therapeutic strategy, such as molecular-targeted therapy.

Identification and Characterization of Daurichromenic Acid Synthase Active in Anti-HIV Biosynthesis.

Daurichromenic acid (DCA) synthase catalyzes the oxidative cyclization of grifolic acid to produce DCA, an anti-HIV meroterpenoid isolated from Rhododendron dauricum We identified a novel cDNA encoding DCA synthase by transcriptome-based screening from young leaves of R. dauricum The gene coded for a 533-amino acid polypeptide with moderate homologies to flavin adenine dinucleotide oxidases from other plants. The primary structure contained an amino-terminal signal peptide and conserved amino acid residues to form bicovalent linkage to the flavin adenine dinucleotide isoalloxazine ring at histidine-112 and cysteine-175. In addition, the recombinant DCA synthase, purified from the culture supernatant of transgenic Pichia pastoris, exhibited structural and functional properties as a flavoprotein. The reaction mechanism of DCA synthase characterized herein partly shares a similarity with those of cannabinoid synthases from Cannabis sativa, whereas DCA synthase catalyzes a novel cyclization reaction of the farnesyl moiety of a meroterpenoid natural product of plant origin. Moreover, in this study, we present evidence that DCA is biosynthesized and accumulated specifically in the glandular scales, on the surface of R. dauricum plants, based on various analytical studies at the chemical, biochemical, and molecular levels. The extracellular localization of DCA also was confirmed by a confocal microscopic analysis of its autofluorescence. These data highlight the unique feature of DCA: the final step of biosynthesis is completed in apoplastic space, and it is highly accumulated outside the scale cells.

Impact of the Omicron Strain on Febrile Convulsions Requiring Hospitalization in Children: A Single-Center Observational Study.

BACKGROUND: The emergence of the Omicron strain of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) at the end of December 2021 has drastically increased the number of infected children in Japan, along with the number of children with febrile convulsions, but its clinical impact is unclear. MATERIALS AND METHODS: We compared the frequency of SARS-CoV-2 infection in children hospitalized with febrile convulsions with the frequency of SARS-CoV-2 infection in children with fever and respiratory symptoms without convulsions. RESULTS: In 2021 and 2022, 49 and 58 children required emergency hospitalization for febrile convulsions (FC group) with status epilepticus or cluster spasms, in which 24 and 38 children underwent a Filmarray® respiratory panel test (FA test), respectively, and others received a quantitative antigen test for SARS-CoV-2. In 2022, only six patients tested positive for SARS-CoV-2 (10.3%, 6/58). As a reference group, 655 children aged <10 years who underwent the FA test for fever and respiratory symptoms during the same period were investigated, and 4 (1.8%, 4/223) and 42 (9.7%, 42/432) tested positive for SARS-CoV-2 in 2021 and 2022, respectively. Rhinovirus/enterovirus (RV/EV) was the most frequently detected virus (40.3%, 264/655), followed by respiratory syncytial virus (RSV) (18.9%, 124/655) and parainfluenza virus 3 (PIV3) (7.8%, 51/655). There was no significant difference in the trend of detected viruses between the two groups. CONCLUSIONS: The frequency and severity of febrile convulsions requiring hospitalization associated with SARS-CoV-2 infection of the Omicron strain may be similar to that of other respiratory viruses in children.

Augmentation of psychiatric symptom onset vulnerability in male mice due to mild traumatic brain injury.

Mild traumatic brain injury (mTBI) can induce psychiatric symptoms, including anxiety, depression, and diminished interest. These symptoms can manifest shortly after injury or exhibit delayed onset months or years later, often worsening in severity. Therefore, early intervention and effective treatment are crucial. However, mTBI lacks clear diagnostic markers, making the underlying pathophysiological mechanisms elusive. Additionally, there is a dearth of suitable animal models and a limited understanding of the biochemical changes in the brain that contribute to post-mTBI psychological symptoms. In this study, we hypothesized that mTBI can trigger brain vulnerability mechanisms, which eventually lead to symptom manifestation in response to subsequent stressors. Using a mouse model, we induced very mild blast-induced mTBI without overt trauma or behavioral changes and subsequently subjected the mice to psychological stress. We analyzed the behavioral alterations and gene expression changes in the brain, focusing on microglial and astrocytic markers involved in the immune system and immune responses. The mice exposed to both blast and defeat stress exhibited significantly lower preference scores in the social interaction test than the mice subjected to blast exposure alone, defeat stress alone, or the control condition. Gene expression analysis revealed a distinct set of genes associated with blast exposure during the development of psychiatric symptoms and genes associated with social defeat stress. The results revealed that neither blast exposure nor defeat stress alone significantly affected mouse social behavior; however, their combined influence resulted in noticeable aberrations in social interactions and/or interest. The findings of the present study provide critical insights into the complex interplay between mTBI and psychological stress. Additionally, they provide a novel mouse model for future research aimed at elucidating the pathophysiological mechanisms underlying the psychiatric symptoms associated with mTBI. Ultimately, this knowledge may enhance early intervention and therapeutic strategies for individuals with mTBI-related psychiatric disorders.

Molecular hydrogen supplementation in mice ameliorates lipopolysaccharide-induced loss of interest.

Aim: The objective of this study was to evaluate the potential of hydrogen in preventing and treating psychiatric symptoms, particularly depressed mood and loss of interest, and to explore its underlying mechanisms. A mouse model exhibiting inflammation-derived depressive symptoms was used for the investigation. Methods: Institute of Cancer Research mice were subjected to a 7-day intervention of either 30% hydrogen or 40 g per day of air via jelly intake. On the final day, lipopolysaccharide (LPS) was intraperitoneally administered at 5 mg/kg to induce inflammation-related depressive symptoms. Behavioral and biochemical assessments were conducted 24 h post-LPS administration. Results: Following LPS administration, a decrease in spontaneous behavior was observed; however, this effect was mitigated in the group treated with hydrogen. The social interaction test revealed a significant reduction in interactions with unfamiliar mice in the LPS-treated group, whereas the hydrogen-treated group exhibited no such decrease. No significant changes were noted in the forced-swim test for either group. Additionally, the administration of LPS in the hydrogen group did not result in a decrease in zonula occludens-1, a biochemical marker associated with barrier function at the cerebrovascular barrier and expressed in tight junctions. Conclusion: Hydrogen administration demonstrated a preventive effect against the LPS-induced loss of interest, suggesting a potential role in symptom prevention. However, it did not exhibit a suppressive effect on depressive symptoms in this particular model. These findings highlight the nuanced impact of hydrogen in the context of inflammation-induced psychiatric symptoms, indicating potential avenues for further exploration and research.

A MinION-based Long-Read Sequencing Application With One-Step PCR for the Genetic Diagnosis of 21-Hydroxylase Deficiency.

CONTEXT: Recently developed long-read sequencing (LRS) technology has been considered an option for CYP21A2 analysis. However, the clinical use of LRS for CYP21A2 analysis is limited. OBJECTIVE: This study's objective is to develop an efficient and low-cost LRS system for CYP21A2 screening. METHODS: A DNA fragment library was prepared in a single polymerase chain reaction (PCR) that covers the entire CYP21A2 gene and all known junctions caused by TNXB gene structural rearrangements, yielding a single 8-kb product of CYP21A2 or CYP21A1P/CYP21A2 chimera. After barcoding, the PCR products were sequenced on a MinION-based platform with Flongle Flow Cell R9.4.1 and R10.4.1. RESULTS: The reference genotypes of 55 patients with 21-hydroxylase deficiency (21OHD) were established using the conventional method with multiplex ligation-dependent probe amplification (MLPA) and nested PCR. LRS using Flongle Flow Cell R9.4.1 yielded consistent results. Additionally, the recently updated LRS "duplex" analysis with Flongle flow cell R10.4.1 was tested to reveal an advantage of accurately sequencing a variant located on the homopolymer region. By introducing a barcode system, the cost was reduced to be comparable to that of conventional analysis. A novel single-nucleotide variation was discovered at the acceptor site of intron 7, c.940-1G > C. We also identified a subtype of the classical chimeric junction CH2, "CH2a," in the region from the latter part of intron 5 to exon 6. CONCLUSION: We successfully established a novel low-cost and highly accurate LRS system for 21OHD genetic analysis. Our study provides insight into the feasibility of LRS for diagnosing 21OHD and other genetic diseases caused by structural rearrangements.

A novel variant of NR5A1, p.R350W implicates potential interactions with unknown co-factors or ligands.

Introduction: NR5A1 and NR5A2 belong to an orphan nuclear receptor group, and approximately 60% of their amino acid sequences are conserved. Transcriptional regulation of NR5A receptors depends on interactions with co-factors or unidentified ligands. Purpose and methods: We employed in vitro and in silico analysis for elucidating the pathophysiology of a novel variant in the ligand-binding domain of NR5A1, p.R350W which was identified from a 46,XY patient with atypical genitalia. Results: In the study, [1] reporter assays demonstrated that R350 is essential for NR5A1; [2] 3D model analysis predicted that R350 interacted with endogenous ligands or unknown cofactors rather than stabilizing the structure; [3] R350 is not conserved in NR5A2 but is specifically required for NR5A1; and [4] none of the 22 known missense variants of the ligand binding domain satisfied all the previous conditions [1]-[3], suggesting the unique role of R350 in NR5A1. Conclusion: Our data suggest that NR5A1 has unidentified endogenous ligands or co-activators that selectively potentiate the transcriptional function of NR5A1 in vivo.

Adrenal suppression and anthropometric data at two years of age was not influenced by the initial hydrocortisone dose in patients with 21-hydroxylase deficiency.

In contrast to the glucocorticoid maintenance therapy employed in patients with 21 hydroxylase deficiency (21OHD), the initial therapy remains to be optimized. The Japanese Society for Pediatric Endocrinology recommends a hydrocortisone (HC) dose of 25-100 mg/m2, which is higher than that employed in Western countries. Herein, we aimed to retrospectively verify the impact of initial HC treatment during infancy and early childhood. Between 2010 and 2018, 15 classical patients with 21OHD were enrolled and divided into the following groups based on initial HC therapy: high dose group (HDG, n = 6), medium dose group (MDG, n = 5), and low dose group (LDG, n = 4). In the HDG and MDG, HC was initiated at 100 mg/m2 and reduced to maintenance doses over 4-6 mo and 2-3 wk, respectively. In the LDG, HC was initiated with a maintenance dose of 7 mg/d, accompanied by fludrocortisone and oral NaCl. During the second year, 17α-hydroxyprogesterone was sufficiently suppressed in all three groups. At two years of age, no significant differences in anthropometric data were observed. Our retrospective study did not reveal any apparent advantages or disadvantages of high-dose initial HC therapy for 21OHD, and a lower dose would be preferable for the initial 21OHD treatment.

Prematurity at less than 24 weeks of gestation is a risk for prolonged hyperglycemia in extremely low-birth weight infants.

Hyperglycemia in extremely low-birth weight infants (ELBWIs) is frequently observed during the acute perinatal phase, (i.e., first 1-2 weeks postnatal period); however it can occasionally persists for >2 weeks, extending to the post-acute phase. Since such prolonged hyperglycemia (PH) is not typical for ELBWIs, the aim of the present study was to further understand the clinical details of PH. Twenty-five hyperglycemic ELBWIs born before 28 weeks of gestation from 2015 to 2018 were included in the study. Based on the duration of hyperglycemia, we separated the subjects into two groups: non-prolonged hyperglycemia (NPH) who achieved remission within ≤2 weeks [n = 18, median 3.0 (range, 2.0-4.0) days], and PH, whose hyperglycemia persisted for >2 weeks [n = 7, median 50.0 (range, 33.5-66.0) days]. Compared to the NPH group, glucose metabolism of the PH group was more deteriorate. The peak blood glucose level was significantly higher in the PH group [PH: median 472 mg/dL, NPH: median 275 mg/dL, p < 0.001], and a higher proportion of subjects in the PH group required insulin therapy [PH: 100% (7/7) vs. NPH: 22% (4/22)]. Multivariate analysis revealed that among perinatal factors, prematurity was the only independent risk factor for PH (glucocorticoid therapy: p = 0.884, gestational age: p = 0.006), with a cutoff of 23W4D determined by receiver operating characteristic analysis. Our data revealed distinctive clinical features of PH, suggesting a type different from the previously reported hyperglycemia in ELBWIs. Specifically, extreme prematurity, less than 24 weeks of gestation, is a risk for PH, and aggressive interventions, such as insulin would be required.

Effect of interaction between a specific subtype of child abuse and the FKBP5 rs1360780 SNP on DNA methylation among patients with bipolar disorder.

BACKGROUND: Child abuse is a risk factor for mood disorders, and linked to decreased DNA methylation (DNAm) of FKBP5 intron 7 through interactions with the single nucleotide polymorphism (SNP) rs1360780. However, no study has investigated which specific subtypes of child abuse are related to decreased DNAm of FKBP5 intron 7 in mood disorders. We therefore aimed to examine the relationship among various subtypes of child abuse, rs1360780, and the DNAm level of FKBP5 intron 7. METHODS: A total of 190 subjects (87 patients with major depressive disorder [MDD], 61 patients with bipolar disorder [BD], and 42 healthy controls) participated. The Child Abuse and Trauma Scale (CATS) was used to evaluate child abuse. Whole blood was processed for genotyping, and pyrosequencing was conducted to assess the DNAm level of FKBP5 intron 7. A multiple regression analysis was used to analyze the DNAm level as a dependent variable, and the CATS subtypes and rs1360780 were used as independent variables. RESULTS: Emotional abuse/neglect, one of the specific subtypes of child abuse, was related to lower DNAm of FKBP5 intron 7 interacting with rs1360780 in the BD patients. There were no significant results in the MDD patients or the controls. LIMITATIONS: Since the study was limited to Japanese individuals, particularly those with MDD and BD, the findings are not generalizable. Furthermore, as child abuse was measured retrospectively, there may be recall bias. CONCLUSIONS: This finding indicates that a specific subtype of child abuse may play an important role in the development of BD.

Relationship between the subtypes of child abuse and affective temperaments: Comparison of depression and bipolar disorder patients and healthy controls using the reclassified Child Abuse and Trauma Scale.

BACKGROUND: We previously reported that child abuse indirectly predicts the diagnosis of major depressive disorder (MDD) or bipolar disorder (BP) based on higher scores of affective temperaments; however, the subtypes of child abuse have not been examined sufficiently. Therefore, in the present study, we used the reclassified version of the Child Abuse and Trauma Scale (CATS) to determine how the subtypes of child abuse affect affective temperaments. METHODS: A total of 502 participants (212 healthy controls, 163 patients with MDD and 127 patients with BP) were administered the Japanese version of the CATS; the Japanese version of the Temperament Evaluation of Memphis, Pisa, Paris, and San Diego Autoquestionnaire; and the Japanese version of the Patient Health Questionnaire-9. Data were analyzed by exploratory and confirmatory factor analyses, as well as by univariate and multivariate analyses. RESULTS: A five-factor structure was appropriate for the CATS. The MDD group scored significantly higher on all subtypes of the reclassified CATS than did the control group. Among the subscales of the reclassified CATS, physical abuse and loneliness/psychological stress were significant predictors of affective temperaments, although all subscales were significantly associated with affective temperaments compared to the original CATS. LIMITATIONS: Since child abuse was assessed retrospectively, there might be recall bias. Furthermore, as the study was limited to Japanese individuals, particularly those with mood disorders, the findings might not be generalizable. CONCLUSIONS: This study revealed that the subtypes of child abuse (especially physical abuse and loneliness/psychological stress) might be associated with MDD and BP.

Gonadal failure among female patients after hematopoietic stem cell transplantation for non-malignant diseases.

In addition to malignant diseases, hematopoietic stem cell transplantation (HSCT) is also a vital option as a curative therapy for non-malignant diseases, such as immunodeficiency, and other hematological disorders. Not only for malignant diseases, but for non-malignant diseases, cytotoxic therapy of conditioning regimens are associated with high risks of adverse effects; however, clinical details regarding the long term outcomes of cytotoxic therapy for non-malignant diseases are not documented yet. To clarify the endocrinological consequences of pediatric HSCT for non-malignant disease patients, we conducted a retrospective analysis. From 1983 to 2014, 75 patients that underwent HSCT for non-malignant diseases were selected for this study. Of these, 23 patients (19 men, 4 women) were continuously followed up in our institute, with regular health check-ups for late effects. Based on a multiple linear regression analysis, the glucocorticoid treatment duration for chronic graft-versus-host disease (cGVHD) and the conditioning regimen were found to be independent predictors of growth retardation. All four female patients developed hypogonadism, and required hormone replacement therapy. The conditioning regimen for the four female patients with hypogonadism was based on the use of alkylating agents, and two female patients were treated with a reduced-intensity conditioning (RIC) regimen. Our study revealed that even the RIC regimen was toxic for the gonads in female patients, and that the survivors of both non-malignant and malignant diseases should be followed up carefully after pediatric HSCT.

Total body irradiation for hematopoietic stem cell transplantation during early childhood is associated with the risk for diabetes mellitus.

BACKGROUND: Hematopoietic stem cell transplantation (HSCT) is a curative treatment for life-threatening malignancies and related diseases. Recently, the long-term prognosis of HSCT during childhood has greatly improved; however, the late adverse effects of HSCT have been found to cause substantial morbidity among long-term survivors. Although metabolic complications, such as diabetes mellitus (DM) and hyperlipidemia (HL), are the major late effects of pediatric HSCT, the clinical details are not clarified sufficiently. METHODS: From 1983 to 2013, 75 participants underwent HSCT in our institute because of malignant or other related diseases. We retrospectively evaluated metabolic complications of eligible 22 participants (14 men and 8 women), and their clinical backgrounds. RESULTS: Among 22 participants, 4 and 9 participants developed DM and HL after HSCT, respectively, and all participants with DM developed HL. None of the participants with DM were obese, and all had substantial insulin resistance. Total body irradiation (TBI) was performed in 10 participants, including 4 participants with DM and 5 participants with HL, revealing that TBI is an independent risk factor for DM. The age at TBI for participants with DM was significantly lower than that for participants without DM (p = 0.01), and all participants with DM received TBI before the age of 6. CONCLUSIONS: Our data suggested that TBI was a risk factor for DM after HSCT, and TBI before the age of six increased the possibility of DM without obesity.

Cause of acute encephalitis/encephalopathy in Japanese children diagnosed by a rapid and comprehensive virological detection system and differences in their clinical presentations.

BACKGROUND: Acute encephalitis/encephalopathy (AE/E) is a rare and severe complication of common childhood infections; however, a treatment strategy based on clinical and pathological evidence has not been established. METHODS: The clinical data and aetiological results using a rapid and comprehensive virological detection system of 62 Japanese children diagnosed with AE/E from 2010 to 2014 were collected. We assessed clinical differences between causes and effectiveness of our multiplex PCR system to establish a pathogen-based treatment strategy for AE/E. RESULTS: Suspected causes were detected in 84% of patients, and our multiplex PCR system contributed to diagnosing 38% of the patients. Furthermore, a negative virus PCR might be important for inferring underlying disease. Most cases were triggered by human herpes virus (HHV) 6/7 (32%) and influenza virus (24%). The causes of AE/E depended on age (p=0.00089) but not on sex (p=0.94). The median age of HHV6/7-associated AE/E was 2.3years, which is lower than the median ages of AE/E associated with other viruses. Major initial treatments were pulse steroid therapy (83.9%) and acyclovir (71%). Most of the patients in this study had good prognoses: 77% recovered without neurological sequalae. CONCLUSIONS: Our virological detection system was useful for detecting the cause of AE/E, and may also contribute to construction of pathogen-based treatment strategies for AE/E. Our data indicated the possibility that early intervention with pulse steroid therapy could be effective for treating AE/E. Further investigation for selection of antiepileptic drugs and additional therapies might be required to prevent progression of AE/E.