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The global prevalence of inflammatory bowel disease (IBD) is increasing. However, population-level data are scarce for Asian populations.To outline and compare paediatric and adult IBD incidence and prevalence data in Korea, describe prescription patterns, and analyse outcomes of anti-tumour necrosis factor (anti-TNF) use in a nationally representative cohort METHODS: IBD was identified based on the presence of Rare and Intractable Disease diagnosis codes for Crohn's disease (CD) and ulcerative colitis (UC). We calculated age-based prevalence and incidence, and examined prescription patterns. We used a Cox proportional hazard model to calculate the hazard ratio (HR) for undergoing surgery.The prevalence of CD increased between 2006 and 2015, particularly among those aged 10-19 years (12.7-35.5 patients per 100,000 people). The use of anti-TNF agents increased from 3.2% to 22.9% in paediatric CD patients. Early use of an anti-TNF agent increased 25-fold in CD patients. Further, CD patients aged 0-14 years were most likely to undergo fistulectomy (HR, 2.63; 95% confidence interval [CI], 1.73-3.97). Children with UC had a higher risk of undergoing surgery (HR, 3.01; 95% CI, 1.33-6.83) than adults. Early use of an anti-TNF agent in CD patients was associated with lower odds of surgery than late-stage use.The prevalence of IBD has increased over time, especially among paediatric patients. Given the magnitude of paediatric IBD disease burden, a multi-faceted approach is needed for early detection and vigilant monitoring to aim for better prognosis.

Research on the gut bacteria in irritable bowel syndrome (IBS) shows discordant results due to inconsistent study designs or small sample sizes. To overcome these issues, we analyzed microbiota of 567 IBS patients and 487 healthy people from 10 shared data sets using a unified method.

The gut covers a large surface area of the body and faces various external factors. The brain works in concert with commensal microbes in the gut to efficiently process the enormous amount of chemical signals that enter the gut every day. This review discusses: 1) evidence that gut bacteria can alter brain development and behavior, 2) mechanisms by which gut bacteria communicate with the brain, 3) preclinical and clinical studies demonstrating the impact of gut microbiota on autism spectrum disorder, and 4) variables worth consideration by future research on gut bacteria.

Following nonpharmaceutical intervention (NPI) to mitigate coronavirus disease 2019 has led to drastic reduction in incidence of communicable disease. Intussusception is commonly preceded by infectious pathogens. Indirect effect from NPI implementation on incidence of intussusception has not been understood fully. We conducted a cohort study to estimate the impact of NPI on incidence of intussusception in Korean children. The net risk ratio of intussusception incidence for 2020 compared to 2010–2019 was 0.53 (95% confidence interval [CI], 0.43–0.64) for boys and 0.56 (95% CI, 0.44–0.71) for girls (P for difference = 0.017). Our study showed an association between NPI implementation and reduction of intussusception incidence, with more profound reduction in boys compared to girls.

Arthrogryposis-renal dysfunction-cholestasis (ARC) syndrome is a rare autosomal recessive multisystemic disease that is associated with the liver, kidney, skin, and central nervous and musculoskeletal systems. ARC occurs as a result of mutations in the VPS33B (Vacuolar protein sorting 33 homolog B) or VIPAR (VPS33B interacting protein, apical-basolateral polarity regulator) genes. A female infant presented with neonatal cholestasis with a severe clinical outcome. She was diagnosed with ARC syndrome using targeted exome sequencing (TES). Exome sequencing revealed compound heterozygous mutations, c.707A>T and c.239+5G>A, in VPS33B, where c.707A>T was a novel variant; the resultant functional protein defects were predicted via in silico analysis. c.239+5G>A, a pathogenic mutation that affects splicing, is found in less than 0.1% of the general population. Invasive techniques, such as liver biopsies, did not contribute to a differential diagnosis of ARC syndrome; thus, early TES together with clinical presentations constituted an apparently accurate diagnostic procedure.

Few studies have described the aetiologies of neonatal cholestasis, and the overall neonatal cholestasis-related mortality (NCM) rate is unclear. We investigated the aetiology and outcome of neonatal cholestasis in a tertiary hospital and developed an NCM prediction model for these patients.Patients aged100 days with serum direct bilirubin (DB) levels of1.0 mg/dL were retrospectively screened. Diagnostic and laboratory data during the 8-week follow-up period after enrolment between 2005 and 2020 were extracted digitally, and medical charts were reviewed manually by clinicians. Logistic regression was used to derive a prediction model for the 1-year mortality outcome of neonatal cholestasis, and performance evaluation and external validation were conducted for the NCM prediction model.We enrolled 4028 neonates with DB of1.0 mg/dL at least once. Prematurity and birth injury (35.4%), complex heart anomalies (18.6%), liver diseases (11.4%), and gastrointestinal anomalies (9.2%) were the most common aetiologies; 398 (9.9%) patients died before one year of age. The peak value of DB was positively correlated to the 1-year mortality rate. In the multivariate analysis, simple laboratory indices, including platelet, prothrombin time, aspartate aminotransferase, albumin, direct bilirubin, creatinine, and C-reactive protein, were independent predictors of 1-year mortality outcome of complete-case subjects. Using these laboratory indices, a logistic regression-based NCM prediction model was constructed. It showed acceptable performances on discrimination (area under the curve, 0.916), calibration (slope, 1.04) and Brier scoring (0.072). The external validation of the sample (n = 920) from two other centres also revealed similar performance profiles of the NCM model.Various aetiologies of neonatal cholestasis were identified in a tertiary hospital, resulting in unfavourable outcomes of a large proportion. The NCM prediction model may have the potential to help clinicians to be aware of high-risk neonatal cholestasis.Ministry of HealthWelfare, Republic of Korea.

Purpose Vitamin D deficiency is a condition widespread throughout the world. Recent studies have suggested that vitamin D deficiency was associated with obesity and metabolic syndrome. The purpose of the study was to examine the relationship between vitamin D deficiency and nonalcoholic fatty liver disease (NAFLD) in adolescents. Methods The data were obtained from the Korean National Health and Nutrition Examination Survey from 2008–2014. A total of 3,878 adolescents were included in the study. Vitamin D deficiency was defined as a 25-hydroxyvitamin D concentration 30 U/L. Results Vitamin D deficiency was noted in 78.9% of the studied population. Age, body mass index, waist circumference, and blood pressure, glucose, cholesterol, and triglyceride levels were significantly higher in adolescents with suspected NAFLD than in adolescents without suspected NAFLD, while the mean vitamin D level was significantly lower in adolescents with suspected NAFLD. The multivariate-adjusted odds of suspected NAFLD were higher with increased age, male gender, obesity, and metabolic syndrome. Individuals with vitamin D deficiency were at higher risk of suspected NAFLD (odds ratio, 1.77; 95% confidence interval, 1.07–2.95) after adjusting for age, gender, obesity, and metabolic syndrome. Conclusion Vitamin D deficiency was associated with suspected NAFLD, independent of obesity and metabolic syndrome, in adolescents.

A few published clinical studies have evaluated the association between gut microbiota in intractable epilepsy, but with inconsistent results. We hypothesized that the factors associated with the gut bacterial composition, such as age and geography, contributed to the discrepancies. Therefore, we used a cohort that was designed to minimize the effects of possible confounding factors and compared the gut microbiota between children with intractable epilepsy and healthy controls. Eight children with intractable epilepsy aged 1 to 7 years and 32 age-matched healthy participants were included. We collected stool samples and questionnaires on their diet and bowel habits at two time points and analyzed the gut microbiota compositions. In the epilepsy group, the amount of Bacteroidetes was lower (Mann&ndash, Whitney test, false discovery rate (FDR) &lt, 0.01) and the amount of Actinobacteria was higher (FDR &lt, 0.01) than in the healthy group. The epilepsy subjects were 1.6- to 1.7-fold lower in microbiota richness indices (FDR &lt, 0.01) and harbored a distinct species composition (p &lt, 0.01) compared to the healthy controls. Species biomarkers for intractable epilepsy included the Enterococcus faecium group, Bifidobacterium longum group, and Eggerthella lenta, while the strongest functional biomarker was the ATP-binding cassette (ABC) transporter. Our study identified gut bacterial dysbiosis associated with intractable epilepsy within the cohort that was controlled for the factors that could affect the gut microbiota.

Aim: To evaluate the long-term effects of nutritional improvement following percutaneous endoscopic gastrostomy (PEG) tube feeding stratified by previous feeding method and to assess the impact of underlying muscle tone on the outcomes of the nutritional intervention. Methods: Neurologically impaired children who underwent PEG tube insertion and nutritional intervention provided by a pediatric nutritional support team were enrolled. We measured anthropometric variables, laboratory parameters, and nutritional intake at baseline, 6 months after PEG insertion, and the last visit. We evaluated the percent ideal body weight (PIBW), body mass index (BMI)-for-age z-score, and percentiles and calculated the ratios of calorie intake compared to required requirement (CIR) and protein intake compared to recommended requirement (PIR). Results: The PIBW and BMI-for-age z-score improved during the first 6 months (p = 0.003 and p = 0.005, respectively). The CIR (p = 0.015) and PIR (p = 0.004) increased during the study period. The baseline BMI and PIBW of the previous nasogastric tube feeding group were better than those of the oral feeding group (p = 0.02 and p = 0.03, respectively). The BMI-for-age z-score, PIBW, CIR, and PIR improved in the hypertonic group (p = 0.03, 0.02, 0.03, and 0.01, respectively). Conclusion: PEG tube feeding and active nutritional intervention improved the nutritional status of neurologically impaired children immediately after PEG insertion. The nutritional requirements might vary by the muscle tonicity.

Background This study aimed to investigate the awareness and application of ROME IV criteria for functional constipation (FC) in real-world practices and assessed differences between pediatric gastroenterologists (PGs) and general pediatricians. Methods A total of 239 (47.8%) out of 500 nationwide pediatricians answered a questionnaire for diagnosis and management of pediatric FC; 60 were PGs (75% of total PGs in Korea). Results A total of 16.6% of pediatricians were aware of the exact ROME IV criteria. Perianal examination and digital rectal examination were practiced less, with a higher tendency among PGs (P < 0.001). Treatment duration was longer among PGs for > 6 months (63.8%) than < 3 months among general pediatricians (59.2%, P < 0.001). Fecal disimpaction and rectal enema were practiced among 78.8% and 58.5% of pediatricians, respectively. High dose medication for initial treatment phase was prescribed by 70.7% of pediatricians, primarily within the first 2 weeks (48.3%). The most commonly prescribed medications in children aged > 1-year were lactulose (59.1%), followed by polyethylene glycol (PEG) 4000 (17.7%), and probiotics (11.8%). Prescription priority significantly differed between PGs and general pediatricians; lactulose or PEG 4000 were most commonly prescribed by PGs (89.7%), and lactulose or probiotics (75.7%) were prescribed by general pediatricians (P < 0.001). For patients aged < 1-year, lactulose (41.6%) and changing formula (31.7%) were commonly prescribed. Most participants recommended diet modification, and PGs more frequently used defecation diary (P = 0.002). Conclusion Discrepancies between actual practice and Rome IV criteria and between PGs and general pediatricians were observed. This survey may help construct practice guidelines and educational programs for pediatric FC., Graphical Abstract

The Committee on Pediatric Obesity of the Korean Society of Pediatric Gastroenterology, Hepatology and Nutrition newly developed the first Korean Guideline on the Diagnosis and Treatment of Obesity in Children and Adolescents to deliver an evidence-based systematic approach to childhood obesity in South Korea. The following areas were systematically reviewed, especially on the basis of all available references published in South Korea and worldwide, and new guidelines were established in each area with the strength of recommendations based on the levels of evidence: (1) definition and diagnosis of overweight and obesity in children and adolescents; (2) principles of treatment of pediatric obesity; (3) behavioral interventions for children and adolescents with obesity, including diet, exercise, lifestyle, and mental health; (4) pharmacotherapy; and (5) bariatric surgery.

Purpose Foreign body (FB) ingestion is common in children, and button battery (BB) ingestion has been increasing in recent years. This study was to identify factors related to outcomes of FB ingestion, particularly BBs in the stomach. We evaluated whether the current recommendations are appropriate and aimed to suggest indications for endoscopic removal of BB in the stomach in young children. Methods We investigated patient age, shape, size, location of FBs, spontaneous passage time and resulting complications among 76 children. We observed types, size, location of BB and outcomes, and analyzed their associations with complications. Results Coins and BB were the two most common FBs. Their shapes and sizes were not associated with the spontaneous passage time. Size, spontaneous passage time, and age were also not associated with any specific complications. For BB ingestion, all 5 cases with lithium batteries (≥1.5 cm, 3 V) presented moderate to major complications in the esophagus and stomach without any symptoms, even when the batteries were in the stomach and beyond the duodenum, while no complications were noted in 7 cases with alkaline batteries (

Objectives Inflammatory bowel disease (IBD) is a chronic lifelong condition and is related to poor quality of life (QoL). The aim of this study was to evaluate the QoL of Asian pediatric patients with IBD and to determine the clinical factors that can influence QoL. Methods Children and adolescents aged 9 to 18 years diagnosed with IBD were enrolled from 7 hospitals. The patients completed the IMPACT-III questionnaire, and clinical data were collected. The results of the questionnaire and the correlation with clinical data were analyzed. Results A total of 208 patients (Crohn disease: n = 166; ulcerative colitis: n = 42) were enrolled. There was no definite QoL difference according to the Paris classification. Female sex (-5.92 ± 2.97, P = 0.0347) and active disease status (-10.79 ± 3.11, P = 0.0006) were significantly associated with poor QoL. Extreme body weight z score and older age at diagnosis were also associated with worse QoL. Conclusions Various clinical factors may affect the QoL in patients with IBD, but determining the overall QoL of patients using only these clinical factors is difficult. Therefore, regular direct measurements of QoL are necessary to better understand patients with IBD.

Background Henoch-Schӧnlein purpura (HSP) is a common vasculitis of childhood. Though HSP is usually self-limiting, severe complications can occur. The management for this condition has not been established yet. Thus, this nationwide study aimed at investigating epidemiological characteristics of children with HSP in Korea. The patterns of clinical practice with regard to the complications of the condition were also investigated. Methods This is a national population-based study that used the National Health Insurance Database. Children below 18 years who were diagnosed with HSP in Korea between 2006 and 2015 were enrolled. Data, such as age, sex, yearly and monthly distribution of HSP, hospitalization, re-hospitalization, comorbidities, and interventions were obtained. The use of steroids was also analyzed. Results A total of 56,841 children were enrolled. The annual incidence of HSP was 55.9 per 100,000 children. The peak age was 5 years. Spring was the most prevalent season. Sex (male) and young age (< 9 years) were risk factors of hospitalization. Younger children were more likely to be re-hospitalized and suspected with intussusception, arthritis, and nephritis. Only 4 children received laparotomy. In total, 57% were managed with steroids, and mean durations of medication were 4-5 days. Children who were hospitalized and those with comorbidities used steroids more frequently (P < 0.001). Conclusion The annual incidence of HSP is 55.9 per 100,000 children which is higher in Korea than that in other countries. Younger children can have a more severe clinical course. This nationwide survey provides valuable information to understand HSP in children and to inspire further research on HSP.

Background Mutations in ATP7B cause Wilson disease (WD). However, direct DNA full sequencing cannot detect all mutations in patients with WD. Multiplex ligation-dependent probe amplification (MLPA) analysis is reportedly useful in increasing the diagnostic yield in other genetic disorders with large deletions or insertions. The aim of this study was to evaluate whether the detection rate of ATP7B mutations can be increased by using MLPA. Methods We enrolled 114 children with WD from 104 unrelated families based on biochemical tests and direct DNA full sequencing. The patients with one or zero mutant allele were investigated using MLPA. We analyzed phenotypic correlations. Results Total allele frequency by full sequencing was 87.5%. Full sequencing revealed two mutant alleles in 80 of 104 unrelated children. One mutant allele was detected in 22 children, and no mutations were found in two children. Novel mutations including small deletions with frameshift mutations were identified by DNA sequencing. MLPA revealed no gross deletion or duplication in 24 children with one or zero mutant alleles. The number of detected mutations was not associated with hepatic manifestation, age of onset, Kayser-Fleischer ring, ceruloplasmin, and urinary Cu concentrations. Conclusion MLPA showed a limited role to increase the mutation detection rate in children who do not receive a definite genetic diagnosis of WD through DNA full sequencing. This finding suggests that large deletions or duplications might be extremely rare in WD. Further development is needed to improve the genetic diagnosis of WD., Graphical Abstract

Purpose No national survey has yet described the guidelines followed by Korean pediatricians to treat acute gastroenteritis (AGE). An online survey was performed to investigate the management of AGE followed by members of The Korean Society of Pediatric Gastroenterology, Hepatology, and Nutrition, and the results were compared between pediatric gastroenterologists (PG) and general pediatricians (GP). Methods Questionnaires were sent to pediatricians between June 2 and 4, 2018 regarding the type of hospital, indications for admission, antiemetic and antidiarrheal drugs and antibiotics prescribed, and dietary changes advised. Results Among the 400 pediatricians approached, 141 pediatricians (35.3%) responded to the survey. PG comprised 39% of the respondents and 72.7% worked at a tertiary hospital. Both PG and GP considered diarrhea or vomiting to be the primary symptom. The most common indication for hospitalization was severe dehydration (98.8%). Most pediatricians managed dehydration with intravenous fluid infusions (PG 98.2%, GP 92.9%). Antiemetics were prescribed by 87.3% of PG and 96.6% of GP. Probiotics to manage diarrhea were prescribed by 89.1% of PG and 100.0% of GP. Antibiotics were used in children with blood in diarrheal stool or high fever. Dietary changes were more commonly recommended by GP (59.3%) than by PG (27.3%) (p

Genotyping of human rotaviruses was performed on 299 (40.1%) rotavirus-positive samples obtained from 745 children with acute diarrhea in three provinces in South Korea between March 2008 and February 2010, approximately 2 years following the introduction of the RotaTeq (September 2007) and Rotarix (July 2008). The most prevalent G genotypes were G1 (51.5%), followed by G3 (24.0%), G4 (15.4%), G9 (6.4%), and G2 (4.7%). The predominant types of P genotypes were P[8] (72.6%), followed by P[6] (19.1%) and P[4] (6.0%). The phylogenetic analyses of the VP7 genes of G9 strains revealed they were highly identical and belonged in lineage III. This study highlights the consistency of the predominant G1 genotype and slightly higher predominance of the identical G9 strains over the G2 genotype.

Background There are few reports on the symptoms of rotavirus infections in neonates. This study aims to describe clinical signs of rotavirus infections among neonates, with a particular focus on preterm infants, and to show the distribution of genotypes in a neonatal intensive care unit (NICU). Methods A prospective observational study was conducted at a regional NICU for 1 year. Stool specimens from every infant in the NICU were collected on admission, at weekly intervals, and from infants showing symptoms. Rotavirus antigens were detected by enzyme-linked immunosorbent assay (ELISA), and genotypes were confirmed by Reverse transcription-Polymerase chain reaction (RT-PCR). The infants were divided into three groups: symptomatic preterm infants with and without rotavirus-positive stools [Preterm(rota+) and Preterm(rota–), respectively] and symptomatic full- or near-term infants with rotavirus-positive stools [FT/NT(rota+)]. Demographic and outcome data were compared among these groups. Results A total of 702 infants were evaluated for rotaviruses and 131 infants were included in this study. The prevalence of rotavirus infections was 25.2%. Preterm(rota+) differed from Preterm(rota–) and FT/NT(rota+) with respect to frequent feeding difficulty ( p = 0.047 and 0.034, respectively) and higher percentage of neutropenia ( p = 0.008 and 0.011, respectively). G4P[6] was the exclusive strain in both the Preterm(rota+) (97.7%) and FT/NT(rota+) (90.2%), and it was the same for nosocomial, institutional infections, and infections acquired at home. Conclusion Systemic illness signs such as feeding difficulty and neutropenia are specific for preterm infants with rotavirus infections. G4P[6] was exclusive, regardless of preterm birth or locations of infections. This study might be helpful in developing policies for management and prevention of rotavirus infections in NICUs.

Among 312 rotavirus-positive samples collected from eight hospitals across South Korea during 2008 and 2009, the most prevalent circulating G genotype was G1 (35.9%), followed by G3 (24.7%), G2 (17.0%), G4 (7.7%), and G9 (2.6%). Notably, one unusual G11 lineage III strain-the first hypoendemic infection case in the world-was found. Of the P genotypes, P[8] (43.9%) was the most common, followed by P[6] (29.5%), P[4] (9.3%) and P[9] (0.6%). Determining G- and P-type combinations showed that G1P[8] was the most prevalent (20.5%), followed by G2P[6] (12.8%) and G3P[8] (12.8%). These findings provide new information concerning the current prevalence and spread of the rare G11 rotavirus.

One hundred forty-six fecal specimens collected between 2007 and 2008 from infants with acute gastroenteritis were screened for rotavirus by ELISA with VP6-specific antibody. One hundred twenty-three of the samples (84.2%) were confirmed to be positive for group A rotavirus (community-acquired, n = 90 [73.2%] and nosocomial, n = 33 [26.8%]), and were typed subsequently using RT-PCR and sequence analysis methods. Determination of G- and P-type combinations showed that G4P[6] (78.9%) was the most common strain, followed by G3P[8] (7.3%), G1P[8] (6.5%), G2P[4] (0.8%), G2P[6] (0.8%), G1P[6] (0.8%), and G9P[8] (0.8%) strains. Of the 97 G4P[6] strains, 62 (63.8%) were responsible for community-acquired cases and 35 (36.1%) were hospital-acquired cases. Phylogenetic analysis of the VP7 gene from the G4P[6] strains revealed that both the community-acquired and nosocomial strains were segregated to the human rotaviruses circulating world-wide, including the prototype vaccinal strain, ST3, which constituted a novel sublineage in lineage 1. Owing to the recent emergence of G4P[6] rotaviruses within the hospital, as well as in the community, the findings from this study are important since they provide new information concerning the community and nosocomial spread of rotaviruses. J. Med. Virol. 82:700–706, 2010. © 2010 Wiley-Liss, Inc.

Growth charts are curves or tables that facilitate the visualization of anthropometric parameters, and are widely used as an important indicator when evaluating the growth status of children and adolescents. The latest version of the Korean National Growth Charts released in 2007 has raised concerns regarding the inclusion of data from both breastfed and formula-fed infants, higher body mass index (BMI) values in boys, and smaller 3rd percentile values in height-for-age charts. Thus, new growth charts have been developed to improve the previous version. The 2006 World Health Organization Child Growth Standards, regarded as the standard for breastfed infants and children, were introduced for children aged 0–35 months. For children and adolescents aged 3–18 years, these new growth charts include height-for-age, weight-for-age, BMI-for-age, weight-for-height, and head circumference-for-age charts, and were developed using data obtained in 1997 and 2005. Data sets and exclusion criteria were applied differently for the development of the different growth charts. BMI-for-age charts were adjusted to decrease the 95th percentile values of BMI. Criteria for obesity were simplified and defined as a BMI of ≥95th percentile for age and sex. The 3rd percentile values for height-for-age charts were also increased. Additional percentile lines (1st and 99th) and growth charts with standard deviation lines were introduced. 2017 Korean National Growth Charts are recommended for the evaluation of body size and growth of Korean children and adolescents for use in clinics and the public health sector in Korea.

We investigated recent epidemiologic trends regarding campylobacteriosis vs. nontyphoidal salmonellosis (NTS), a previously known leading cause of bacterial enterocolitis in Korean children. Among 363 hospitalized children with acute inflammatory diarrhea, Campylobacter (18.7%) was the most frequently detected pathogen using multiplex polymerase chain reaction tests followed by Salmonella (15.4%). Children with campylobacteriosis were older than children with NTS (112.6 months [interquartile range (IQR) 66.0–160.1] vs. 53 months [IQR 31.0–124.0], P < 0.001) and had higher prevalences of abdominal cramping and stool hemoglobin. Campylobacteriosis may be suspected as a primary cause of acute inflammatory diarrhea in hospitalized school-aged Korean children and adolescents., Graphical Abstract

Familial Mediterranean fever (FMF) is the most common Mendelian autoinflammatory disease, characterized by uncontrolled activation of the innate immune system that manifests as recurrent brief fever and polyserositis (e.g., peritonitis, pleuritic, and arthritis). FMF is caused by autosomal recessive mutations of the Mediterranean fever gene, MEFV which encodes the pyrin protein. Although FMF predominantly affects people from Mediterranean and Middle Eastern ethnic origins, 3 cases of FMF have been reported in Korea since 2012. We report another case of FMF in Korea in which the patient presented with a month-long fever without serositis. After treatment with colchicine was initiated, the patient’s symptoms quickly subsided. The response to colchicine was helpful for diagnosis. We compare the FMF genotypes in Korea with in other countries. Studying FMF cases in Korea will help establish the best MEFV exons to use for screening and diagnosis of Korean FMF.

Cystic fibrosis (CF) is an autosomal recessive disease that is very rare in Asians: only a few cases have been reported in Korea. We treated a female infant with CF who had steatorrhea and failure to thrive. Her sweat chloride concentration was 102.0 mM/L. Genetic analysis identified two novel mutations including a splice site mutation (c.1766+2T>C) and a frameshift mutation (c.3908dupA; Asn1303LysfsX6). Pancreatic enzyme replacement and fat-soluble vitamin supplementation enabled the patient to get a catch-up growth. This is the first report of a Korean patient with CF demonstrating pancreatic insufficiency. CF should therefore be considered in the differential diagnosis of infants with steatorrhea and failure to thrive.

Gastroesophageal reflux disorder (GERD) is the most common esophageal disorder in children. Achalasia occurs less commonly but has similar symptoms to GERD. A nine-year old boy presented with vomiting, heartburn, and nocturnal cough. The esophageal impedance-pH monitor revealed nonacidic GERD (all-refluxate clearance percent time of 20.9%). His symptoms persisted despite medical treatment for GERD, and he was lost to follow up. Four years later, he presented with heartburn, solid-food dysphagia, daily post-prandial vomiting, and failure to thrive. Endoscopy showed a severely dilated esophagus with candidiasis. High-resolution manometry was performed, and he was diagnosed with classic achalasia (also known as type I). His symptoms resolved after two pneumatic dilatation procedures, and his weight and height began to catch up to his peers. Clinicians might consider using high-resolution manometry in children with atypical GERD even after evaluation with an impedance-pH monitor.

Clostridium difficile infection has been increasing since 2000 in children and in adults. Frequent antibiotics use, comorbidity, and the development of hypervirulent strains have increased the risk of infection. Despite the high carriage rates of C. difficile, infants rarely develop clinical infection. Discontinuing antibiotics and supportive management usually leads to resolution of disease. Antibiotics use should be stratified depending on the patient's age and severity of the disease.

Neonatal-onset inflammatory bowel disease (IBD) accounts for only 0.25% of pediatric IBD cases. The molecular pathogenesis of IBD remains unclear. Recently, rare Mendelian mutations have been identified in children with very early-onset Crohn's disease and ulcerative colitis. In this study, we report compound heterozygous mutations in the interleukin-10 receptor A (IL-10RA) gene in children with severe neonatal-onset IBD. Patient 1 had chronic diarrhea within the first month of life and had perianal fistulae. She was diagnosed with 'intractable ulcerating enterocolitis in infancy' and underwent subtotal colectomy at the age of 24 months because of poor response to immunosuppressant therapy. Compound heterozygous mutations, c.[301C>T];[350G>A](p.[R101W];[R117H]), were discovered in IL-10RA for this patient. Patient 2 presented symptoms within the first month of life and was diagnosed with Crohn's disease. Severe colitis and perianal and enteroenteric fistulae occurred repeatedly, and he underwent surgical management involving colectomy, colostomy, and ileostomy. We identified mutations in IL-10RA, c.[272A>G];[784C>T] (p.[Y91C];[R262C]). Patient 3 had chronic diarrhea and a rectovaginal fistula at 3 days of life and was diagnosed with Crohn's disease. She underwent fistulectomy and ileostomy, but experienced frequent relapses. Mutations, c.[272A>G];[301C>T] (p.[Y91C];[R101W]), were found in IL-10RA. This report confirms the genetic defect of IL-10RA in neonatal-onset IBD including 'intractable ulcerating enterocolitis in infancy'.

The gut mucosal barrier plays an important role in maintaining a delicate immune homeostasis. The pathogenesis of inflammatory bowel disease (IBD) is considered to involve a defective mucosal immunity along with a genetic predisposition. Recent views have suggested an excessive response to components of the gut microbiota in IBD. A condition of "dysbiosis", with alterations of the gut microbial composition, has been observed in patients with IBD. In this article, the author review recent studies of gut microbiota in IBD, particularly the importance of the gut microbiota in the pathogenesis of pediatric IBD.

Fecal samples were serially collected within 72 h after birth and at 1, 2, and 4-6 weeks of age from preterm infants in the neonatal intensive care units (NICUs) of two different university hospitals. Total bacterial DNA was extracted from each fecal sample from 49 infants, and polymerase chain reaction (PCR) was performed with primers for the 16S gene of

Acute diarrhea is one of the most common symptoms in children. Common causes and differential diagnosis are reviewed in this article. In children with suspicious diarrhea, one should consider whether the stool is normal variant or true diarrhea and in the case of true diarrhea, whether it is infectious or noninfectious diarrhea, particularly bacterial or viral infection; last, in the case of bacterial infection, whether antibiotics is needed or not. Rotaviruses and noroviruses are the most common causes in children with acute diarrhea. The seasonal distribution of rotavirus infection is changing. Epidemics of norovirus are increasing. The main symptom of norovirus infection in children is vomiting, unlike rotavirus infection. Bacterial infection is not a common cause. When a child shows bloody and mucoid diarrhea, the use of antibiotics should be considered if the patient is a young infant, is immunocompromised, or has toxic symptoms such as high fever, severe dehydration, or malnutrition. Clinical approaches focused on etiology can support the proper management and prediction of prognosis. Genetic epidemiology research is needed to monitor the efficacy of rotavirus vaccination and to develop a norovirus vaccine.