Usefulness of functional splicing analysis to confirm precise disease pathogenesis in Diamond-Blackfan anemia caused by intronic variants in RPS19

Diamond-Blackfan anemia (DBA) is mainly caused by pathogenic variants in ribosomal proteins and 22 responsible genes have been identified to date. The most common causative gene of DBA is RPS19 [NM_001022.4]. Nearly 180 RPS19 variants have been reported, including three deep intronic variants outside the splicing consensus sequence (c.72-92A > G, c.356 + 18G > C, and c.411 + 6G > C). We also identified one case with a c.412-3C > G intronic variant. Without conducting transcript analysis, the pathogenicity of these variants is unknown. However, it is difficult to assess transcripts because of their fragility. In such cases, in vitro functional splicing assays can be used to assess pathogenicity. Here, we report functional splicing analysis results of four RPS19 deep intronic variants identified in our case and in previously reported cases. One splicing consensus variant (c.411 + 1G > A) was also examined as a positive control. Aberrant splicing with a 2-bp insertion between exons 5 and 6 was identified in the patient samples and minigene assay results also identified exon 6 skipping in our case. The exon 6 skipping transcript was confirmed by further evaluation using quantitative RT-PCR. Additionally, minigene assay analysis of three reported deep intronic variants revealed that none of them showed aberrant splicing and that these variants were not considered to be pathogenic. In conclusion, the minigene assay is a useful method for functional splicing analysis of inherited disease.

Contradiction between genetic analysis and diuretic loading test in type I Bartter syndrome: a case report

BACKGROUND

In typical cases of Bartter syndrome (BS), assessing response to diuretics (furosemide and thiazide), hereinafter referred to as diuretic loading test, may be used to diagnose the type by detecting which part of the kidney tubule is not functioning correctly. However, the diuretic loading test may not always agree with the results of genetic analyses.

CASE PRESENTATION

A 5-year-old boy was admitted due to lower extremity weakness and abnormal gait. He had a recurrent episode of muscle weakness and laboratory results showed severe hypokalemia. The direct genomic sequencing of the case revealed a new mutation in the SLC12A1 gene, which is associated with type I Bartter syndrome. Because there was the difference between the phenotype and genotype, we conducted a diuretic loading test to confirm the diagnosis. However, the results showed a clear increase in urine excretion of Na and Cl. These results were not consistent with typical type I BS, but consistent with the patient's phenotype.

CONCLUSION

The diuretic loading test has limited utility for diagnosis especially in atypical cases. On the other hand, this test, which allows assessment of channel function, is useful for better understanding of the genotype-phenotype correlation.

Prevalence of Wilson disease based on genome databases in Japan

BACKGROUND

Wilson disease (WD) is an autosomal recessive disorder caused by mutations in the ATP7B gene. In 1984, Scheinberg and Sternlieb estimated the prevalence of WD to be 1:30 000. However, recent epidemiological studies have reported increasing prevalence rates in different populations. The carrier frequency of ATP7B variants and the prevalence of WD in the Japanese population have not been reported using multiple databases.

METHODS

Multiple public databases were used. First, we included mutations in the ATP7B gene that were registered in the Human Gene Mutation Database (HGMD) Professional, where 885 ATP7B variants were identified as pathogenic. Next, we investigated the allele frequencies of these 885 variants in Japanese individuals using the Human Genetic Variation Database (HGVD) and the Japanese Multi Omics Reference Panel (jMorp).

RESULTS

Of the 885 variants of ATP7B, 7 and 12 missense and nonsense variants, zero and three splicing variants, and zero and two small deletions were found in the HGVD and in jMorp, respectively. The total allele frequencies of the ATP7B mutations were 0.011 in the HGVD and 0.014 in the jMorp. According to these data, the carrier frequencies were 0.022 (2.2%) and 0.028 (2.8%), respectively, and patient frequencies were 0.000121 (1.21/10 000 individuals) and 0.000196 (1.96/10 000 individuals), respectively.

CONCLUSIONS

This is the first study to report the carrier frequency of ATP7B variants and the prevalence of WD in Japan using multiple databases. The calculated prevalence of WD was comparatively higher than that of previous reports, indicating previous underdiagnosis or the existence of less severe phenotypes.

Early steroid pulse therapy for children with suspected acute encephalopathy: An observational study

Steroid pulse therapy is widely used to treat virus-associated acute encephalopathy, especially the cytokine storm type; however, its effectiveness remains unknown. We sought to investigate the effectiveness of early steroid pulse therapy for suspected acute encephalopathy in the presence of elevated aspartate aminotransferase (AST) levels.We enrolled children admitted to Hyogo Children's Hospital between 2003 and 2017 with convulsions or impaired consciousness accompanied by fever (temperature >38°C). The inclusion criteria were: refractory status epilepticus or prolonged neurological abnormality or hemiplegia at 6 hours from onset, and AST elevation >90 IU/L within 6 hours of onset. We excluded patients with a neurological history. We compared the prognosis between the groups with or without steroid pulse therapy within 24 hours. A good prognosis was defined as a Pediatric Cerebral Performance Category Scale (PCPC) score of 1-2 at the last evaluation, within 30 months of onset. Moreover, we analyzed the relationship between prognosis and time from onset to steroid pulse therapy.Fifteen patients with acute encephalopathy and 5 patients with febrile seizures were included in this study. Thirteen patients received steroid pulse therapy within 24 hours. There was no between-group difference in the proportion with a good prognosis. There was no significant correlation between PCPC and timing of steroid pulse therapy (rs = 0.253, P = .405). Even after excluding 2 patients with brainstem lesions, no significant correlation between PCPC and steroid pulse therapy timing (rs = 0.583, P = .060) was noted. However, the prognosis tended to be better in patients who received steroid pulse therapy earlier.Steroid pulse therapy within 24 hours did not improve the prognosis in children with suspected acute encephalopathy associated with elevated AST. Still, even earlier administration of treatment could prevent the possible neurological sequelae of this condition.

Spinal Muscular Atrophy: Diagnosis, Incidence, and Newborn Screening in Japan

Spinal muscular atrophy (SMA) is a genetic neuromuscular disorder that causes degeneration of anterior horn cells in the human spinal cord and subsequent loss of motor neurons. The severe form of SMA is among the genetic diseases with the highest infant mortality. Although SMA has been considered incurable, newly developed drugs-nusinersen and onasemnogene abeparvovec-improve the life prognoses and motor functions of affected infants. To maximize the efficacy of these drugs, treatments should be started at the pre-symptomatic stage of SMA. Thus, newborn screening for SMA is now strongly recommended. Herein, we provide some data based on our experience of SMA diagnosis by genetic testing in Japan. A total of 515 patients suspected of having SMA or another lower motor neuron disease were tested. Among these patients, 228 were diagnosed as having SMA with survival motor neuron 1 (SMN1) deletion. We analyzed the distribution of clinical subtypes and ages at genetic testing in the SMN1-deleted patients, and estimated the SMA incidence based on data from Osaka and Hyogo prefectures, Japan. Our data showed that confirmed diagnosis by genetic testing was notably delayed, and the estimated incidence was 1 in 30,000-40,000 live births, which seemed notably lower than in other countries. These findings suggest that many diagnosis-delayed or undiagnosed cases may be present in Japan. To prevent this, newborn screening programs for SMA (SMA-NBS) need to be implemented in all Japanese prefectures. In this article, we also introduce our pilot study for SMA-NBS in Osaka Prefecture.

TRENDS IN THE PREVALENCE OF FRAILTY IN JAPAN: A META-ANALYSIS FROM THE ILSA-J

OBJECTIVE

To examine whether age-specific prevalence of frailty in Japan changed between 2012 and 2017.

DESIGN

This study performed meta-analyses of data collected from 2012 to 2017 using the Integrated Longitudinal Studies on Aging in Japan (ILSA-J), a collection of representative Japanese cohort studies.

SETTING

The ILSA-J studies were conducted on community-living older adults.

PARTICIPANTS

ILSA-J studies were considered eligible for analysis if they assessed physical frailty status and presence of frailty in the sample. Seven studies were analyzed for 2012 (±1 year; n = 10312) and eight studies were analyzed for 2017 (±1 year; n = 7010). Five studies were analyzed for both 2012 and 2017.

MEASUREMENTS

The study assessed the prevalence of frailty and frailty status according to 5 criteria: slowness, weakness, low activity, exhaustion, and weight loss.

RESULTS

The overall prevalence of physical frailty was 7.0% in 2012 and 5.3% in 2017. The prevalence of frailty, especially in people 70 years and older, tended to decrease in 2017 compared to 2012. Slight decreases were found in the prevalence of frailty subitems including weight loss, slowness, exhaustion, and low activity between 2012 and 2017, but change in the prevalence of weakness was weaker than other components.

CONCLUSIONS

The prevalence of physical frailty decreased from 2012 to 2017. There are age- and gender-related variations in the decrease of each component of frailty.

Genotype-Phenotype Correlation in WT1 Exon 8 to 9 Missense Variants

Introduction

WT1 missense mutation in exon 8 or 9 causes infantile nephrotic syndrome with early progression to end-stage kidney disease (ESKD), Wilms tumor, and 46,XY female. However, some patients with missense mutations in exon 8 or 9 progress to ESKD in their teens or later. Therefore, we conducted a systematic review and functional analysis of WT1 transcriptional activity.

Methods

We conducted a systematic review of 174 cases with WT1 exon 8 or 9 missense variants from our cohort (n=13) and previous reports (n=161). Of these cases, mild and severe genotypes were selected for further in vitro functional analysis using luciferase assay.

Results

The median age of developing ESKD was 1.17 years. A comparative study was conducted among three WT1 genotype classes: mutations of the DNA-binding site (DBS group), mutations outside the DNA-binding site but at sites important for zinc finger structure formation by 2 cysteines and 2 histidines (C2H2 group), and mutations leading to other amino acid changes (Others group). The DBS group showed the severest phenotype and the C2H2 group was intermediate, whereas the Others group showed the mildest phenotype (developing ESKD at 0.90, 2.00, and 3.92 years, respectively, with significant differences). In vitro functional analysis showed dominant-negative effects for all variants; in addition, the DBS and C2H2 mutations were associated with significantly lower WT1 transcriptional activity than the other mutations.

Conclusion

Not only the DNA-binding site but also C2H2 zinc finger structure sites are important for maintaining WT1 transcriptional activity, and their mutation causes severe clinical symptoms.

Limited correlation between tumor markers and minimal residual disease detected by seven neuroblastoma-associated mRNAs in high-risk neuroblastoma patients

Vanillylmandelic acid (VMA), homovanillic acid (HVA), neuron-specific enolase (NSE) and lactate dehydrogenase (LDH) are classical tumor markers and are used as standard clinical evaluations for patients with neuroblastoma (NB). Minimal residual disease (MRD) can be monitored by quantifying several sets of NB-associated mRNAs in the bone marrow (BM) and peripheral blood (PB) of patients with NB. Although MRD in BM and PB has been revealed to be a strong prognostic factor that is independent of standard clinical evaluations, its interrelation with tumor markers remains uncharacterized. The present study determined the levels of tumor markers (VMA, HVA, NSE and LDH) and MRD (BM-MRD and PB-MRD) in 133 pairs of concurrently collected BM, PB and urine samples from 19 patients with high-risk NB. The patients were evaluated during the entire course of treatment, which included 10 diagnoses, 32 treatments, 36 post-treatment, 9 relapses and 46 post-relapse sample pairs. The level of BM-MRD and PB-MRD was determined by quantifying 7 NB-mRNAs (collapsin response mediator protein 1, dopamine beta-hydroxylase, dopa decarboxylase, growth-associated protein 43, ISL LIM homeobox 1, pairedlike homeobox 2b and tyrosine hydroxylase) using droplet digital PCR. In overall sample pairs, tumor markers (VMA, HVA, NSE and LDH) demonstrated weak but significant correlations (P<0.011) with BM-MRD and PB-MRD. In subgroups according to each patient evaluation, the degree of correlation between tumor markers and MRD became stronger in patients with adrenal gland tumors, BM metastasis at diagnosis and relapse/regrowth compared with overall sample pairs. In contrast, tumor markers demonstrated variable correlations with MRD in subgroups according to each sample evaluation (BM infiltration at sampling, collection time point and disease status). The results suggested that tumor markers may demonstrate limited correlation with MRD in patients with high-risk NB.

Prognosis and acute complications at the first onset of idiopathic nephrotic syndrome in children: a nationwide survey in Japan (JP-SHINE study)

BACKGROUND

Information on the epidemiology of idiopathic nephrotic syndrome (INS) in children, complications of INS and the side effects of steroid therapy is scarce.

METHODS

The Japanese Pediatric Survey Holding Information of Nephrotic Syndrome, a nationwide cohort study, was conducted by the Japanese Study Group of Renal Disease in Children and enrolled 2099 children with newly diagnosed INS between 1 January 2010 and 31 December 2012. We conducted a follow-up study of the complications during the first onset and the patients' prognosis in this cohort.

RESULTS

We obtained follow-up data on 999 children (672 males) with a median age at onset of 4.5 years [interquartile range (IQR) 2.8-9.4] and a median follow-up period of 4.1 years (IQR 2.5-5.1). At the first onset, 24% of patients experienced severe acute kidney injury (AKI), defined as a serum creatinine increase to a level two or more times the baseline. On logistic regression analysis, age, hematuria, severe hypoalbuminemia (serum albumin <1.0 g/dL) and severe bacterial infection were not independent factors, but female sex {hazard ratio [HR] 1.5 [95% confidence interval (CI) 1.1-1.7]} and hypertension [HR 4.0 (95% CI 2.6-6.0)] were significantly related to AKI. During the observation period, ocular hypertension requiring treatment occurred in 17.4% of patients, among which 0.4% received surgical treatment. Progression to frequently relapsing nephrotic syndrome/steroid-dependent nephrotic syndrome in 3 years was seen in 44.2% of the patients and was shown by the Cox regression analysis to be significantly related to younger age and days until remission at the first episode, but not to sex, hematuria, the minimum serum albumin level or AKI. Two patients died during the observation period. One patient showed progression to end-stage kidney disease.

CONCLUSION

Based on the results of a multicenter questionnaire survey, the overall survival and renal survival rates were found to be excellent. However, proper management of complications, particularly in AKI and ocular hypertension, is mandatory.

Minimal residual disease in high-risk neuroblastoma shows a dynamic and disease burden-dependent correlation between bone marrow and peripheral blood

•

Bone marrow is the most frequent site of metastasis and relapse for neuroblastoma.

•

Minimal residual disease has been identified in bone marrow and peripheral blood (BM-MRD and PB-MRD) by quantifying several sets of neuroblastoma-associated mRNAs.

•

BM-MRD has significant prognostic information for high-risk neuroblastoma.

•

BM-MRD and PB-MRD show a dynamic and disease burden-dependent correlation in high-risk neuroblastoma.

Neuroblastoma (NB) is the most common extracranial solid tumor in children and originates from sympathoadrenal or Schwann cell precursors derived from neural crest. These neural crest derivatives also constitute the hematopoietic and mesenchymal stem cells in bone marrow (BM) that is the most frequent site of NB metastasis and relapse. In NB patients, NB cells have been pathologically detected in BM and peripheral blood (PB), and minimal residual disease (MRD) in BM and PB (BM-MRD and PB-MRD) can be monitored by quantitating several sets of NB-associated mRNAs (NB-mRNAs). Although previous studies have shown varying degrees of correlation between BM-MRD and PB-MRD, the underlying factors and/or mechanisms remains unknown. In the present study, we determined the levels of BM-MRD and PB-MRD by quantitating seven NB-mRNAs in 133 pairs of concurrently collected BM and PB samples from 19 high-risk NB patients with clinical disease evaluation, and examined their correlation in overall and subgroups of sample pairs. The levels of BM-MRD and PB-MRD were moderately (r = 0.418, p < 0.001) correlated with each other in overall sample pairs. The correlation became strong (r = 0.725, p < 0.001), weak (r = 0.284, p = 0.008), and insignificant (p = 0.194) in progression, stable, and remission subgroups of sample pairs, respectively. It also became stronger in subgroups of sample pairs with poor treatment responses and poor prognostic factors. Present study suggests that MRD in high-risk NB shows a dynamic and disease burden-dependent correlation between BM and PB.

A case of 17q12 deletion syndrome that presented antenatally with markedly enlarged kidneys and clinically mimicked autosomal recessive polycystic kidney disease

The gene encoding hepatocyte nuclear factor 1β (HNF1B), a transcription factor involved in the development of the kidney and other organs, is located on chromosome 17q12. Heterozygous deletions of chromosome 17q12, which involve 15 genes including HNF1B, are known as 17q12 deletion syndrome and are a common cause of congenital anomalies of the kidneys and urinary tract (CAKUT) and may also present as a multisystem disorder. Autosomal recessive polycystic kidney disease (ARPKD), on the other hand, is a severe form of polycystic kidney disease caused by mutations in PKHD1 (polycystic kidney and hepatic disease 1). It is important to differentiate between these two diseases because they differ significantly in inheritance patterns, renal prognosis, and extrarenal manifestations. Here we report a case of 17q12 deletion syndrome that clinically mimicked ARPKD in which genetic testing was essential for appropriate genetic counseling and monitoring of possible extrarenal manifestations. The patient presented antenatally with markedly enlarged kidneys and showed bilaterally hyperechoic kidneys with poor corticomedullary differentiation and multiple cysts on ultrasonography. There was no family history of renal disease. ARPKD was clinically suspected and genetic testing was performed to confirm diagnosis, resulting in an unexpected finding of 17q12 deletion including HNF1B. While some research has been done to identify patients that should be tested for HNF1B anomalies, this case illustrates the difficulty of recognizing HNF1B-related disease and the importance of genetic testing in appropriately managing CAKUT cases.

Prediction of AESD and neurological sequelae in febrile status epilepticus

OBJECTIVE

The clinical prediction rule (CPR) for acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) was developed with an area under the receiver operating characteristic curve (AUC) of 0.95 - 0.96. Our objective was to verify the AESD CPR in a new cohort and compare the utilities of three CPRs of acute encephalopathy: the Tada, Yokochi, and Nagase criteria.

METHODS

We reviewed the clinical data and medical charts of 580 consecutive patients (aged < 18 years) with febrile convulsive status epilepticus lasting for ≥ 30 min in 2002 - 2017 and measured the performance of the CPRs in predicting AESD and sequelae.

RESULTS

The CPRs predicted AESD with an AUC of 0.84 - 0.88. The Tada criteria predicted AESD with a positive predictive value (PPV) of 0.25 and a negative predictive value (NPV) of 0.99. The Yokochi criteria predicted AESD with a PPV and NPV of 0.20 and 0.95, respectively, after 12 h. The Nagase criteria predicted AESD with a PPV and NPV of 0.14 and 1.00, respectively, after 6 h. The PPVs of the Tada, Yokochi, and Nagase criteria for sequelae were 0.28, 0.28, and 0.17, respectively; the corresponding NPVs were 0.97, 0.95, and 0.98, respectively.

CONCLUSIONS

The effectiveness of the AESD CPR in a new cohort was lower than that in the derivation study. CPRs are not sufficient as diagnostic tests, but they are useful as screening tests. The Nagase criteria are the most effective for screening among the three CPRs due to their high NPV and swiftness.

Bilirubin/albumin (B/A) ratios correlate with unbound bilirubin levels in preterm infants

BACKGROUND

A strong correlation between the bilirubin/albumin (B/A) ratio and unbound bilirubin (UB) levels in newborns ≥35 weeks of gestation has been reported. However, in preterm infants, the usefulness of B/A ratios remains unclear.

METHODS

We obtained serum from 381 newborns <35 weeks of gestation. UB levels were measured using the glucose oxidase-peroxidase method. Total serum bilirubin (TB) and albumin (Alb) concentrations were measured spectrophotometrically. Samples were then stratified into two groups based on the infant's phototherapy use. B/A ratios were calculated and correlated with UB levels. Samples taken from infants prior to or never receiving phototherapy (No PTx) were then stratified by gestational age (GA) epochs: 22-27, 28-29, 30-31, and 32-34 weeks and B/A ratios correlated with UB levels.

RESULTS

B/A ratios significantly correlated with UB levels in samples from the No PTx cohort (n = 1250; y = 1.83x - 0.15, r² = 0.93) when compared with samples from infants post-phototherapy (Post-PTx, n = 2039; y = 1.05x + 0.09, r² = 0.69). Even when stratified by GA, the correlation remained.

CONCLUSIONS

In preterm infants <35 weeks of gestation, B/A ratios correlated with UB levels better in infants prior to or never receiving phototherapy than in those infants receiving phototherapy.

IMPACT

The bilirubin/albumin (B/A) ratio significantly correlates with unbound bilirubin (UB) levels in preterm infants <35 weeks of gestation. The B/A ratio can be used as an index of UB levels in preterm infants <35 weeks of gestation. The B/A ratio is useful, especially when UB measurements are not available, for managing hyperbilirubinemia in preterm infants.

Heterozygous missense variant in TRPC6 in a boy with rapidly progressive infantile nephrotic syndrome associated with diffuse mesangial sclerosis

Transient receptor potential channel C6 encoded by TRPC6 is involved in slit diaphragm formation in podocytes, and abnormalities of the TRPC6 protein cause various glomerular diseases. The first identified pathogenic variant of TRPC6 was found to cause steroid-resistant nephrotic syndrome that typically developed in adulthood and then slowly led to end-stage renal disease, along with a renal pathology of focal segmental glomerulosclerosis. Here, we report a patient with rapidly progressing infantile nephrotic syndrome and a heterozygous missense TRPC6 variant. The patient, a 2-year-old Japanese boy, developed steroid-resistant nephrotic syndrome at age 11 months. His renal function deteriorated rapidly, and peritoneal dialysis was introduced at age 1 year and 6 months. His renal pathology, obtained at age 1 year and 1 month, was consistent with diffuse mesangial sclerosis (DMS). Clinical exome analysis and custom panel analysis for hereditary renal diseases revealed a reported heterozygous missense variant in TRPC6 (NM_004621.5:c.523C > T:p.Arg175Trp). This is the first report of a patient with a TRPC6-related renal disorder associated with DMS.

Biallelic variants in LIG3 cause a novel mitochondrial neurogastrointestinal encephalomyopathy

Abnormal gut motility is a feature of several mitochondrial encephalomyopathies, and mutations in genes such as TYMP and POLG, have been linked to these rare diseases. The human genome encodes three DNA ligases, of which only one, ligase III (LIG3), has a mitochondrial splice variant and is crucial for mitochondrial health. We investigated the effect of reduced LIG3 activity and resulting mitochondrial dysfunction in seven patients from three independent families, who showed the common occurrence of gut dysmotility and neurological manifestations reminiscent of mitochondrial neurogastrointestinal encephalomyopathy. DNA from these patients was subjected to whole exome sequencing. In all patients, compound heterozygous variants in a new disease gene, LIG3, were identified. All variants were predicted to have a damaging effect on the protein. The LIG3 gene encodes the only mitochondrial DNA (mtDNA) ligase and therefore plays a pivotal role in mtDNA repair and replication. In vitro assays in patient-derived cells showed a decrease in LIG3 protein levels and ligase activity. We demonstrated that the LIG3 gene defects affect mtDNA maintenance, leading to mtDNA depletion without the accumulation of multiple deletions as observed in other mitochondrial disorders. This mitochondrial dysfunction is likely to cause the phenotypes observed in these patients. The most prominent and consistent clinical signs were severe gut dysmotility and neurological abnormalities, including leukoencephalopathy, epilepsy, migraine, stroke-like episodes, and neurogenic bladder. A decrease in the number of myenteric neurons, and increased fibrosis and elastin levels were the most prominent changes in the gut. Cytochrome c oxidase (COX) deficient fibres in skeletal muscle were also observed. Disruption of lig3 in zebrafish reproduced the brain alterations and impaired gut transit in vivo. In conclusion, we identified variants in the LIG3 gene that result in a mitochondrial disease characterized by predominant gut dysmotility, encephalopathy, and neuromuscular abnormalities.

Multivariate analysis of the impact of weather and air pollution on emergency department visits for night-time headaches among children: retrospective, clinical observational study

OBJECTIVES

To examine the association between the number of visits to the emergency department (ED) by children for night-time headaches and exposure to multifaceted factors, such as meteorological conditions and air pollution.

DESIGN

We conducted a clinical observational time-series analysis study.

SETTING

We reviewed consecutive patients younger than 16 years of age at the primary ED centre in Kobe city, Japan, during the night shift (19:30-7:00 hours) between 1 January 2011 and 31 December 2019.

PARTICIPANTS

In total, 265 191 children visited the ED; 822 presented with headache during the study period.

PRIMARY OUTCOME MEASURES

We investigated the effects of meteorological factors and air pollutants by multivariate analysis of Poisson regression estimates. A subanalysis included the relationship between the number of patients with night-time headaches and the above factors by sex. Furthermore, the effect of typhoon landing on patient visits for headache was also analysed. Headache was not classified because examinations were performed by general paediatricians (non-specialists).

RESULTS

The number of patients with night-time headaches displayed distinct seasonal changes, with peaks during the summer. Multivariate analysis of Poisson regression estimates revealed a significant positive relationship between the number of patients for headache and mean temperature. Subanalysis by sex indicated a positive relationship between the number of patients with headache and mean temperature in both sexes; however, it was significant only for females. No relationship was found between the number of patients with headache and air pollution. There was no change in the number of patients for night-time headaches 3 days before and after typhoon landing.

CONCLUSIONS

High temperature is the main factor for visiting ED for night-time headaches among children in Kobe city. Our results suggest that preventive measures against night-time headaches may be possible by reducing time spent outside during summer.

Association of residual gastric acid secretion with persistent symptoms in gastroesophageal reflux disease patients receiving standard-dose proton pump inhibitor therapy

BACKGROUND

Although a third of gastroesophageal reflux disease (GERD) patients are refractory to proton pump inhibitor (PPI) therapy, the underlying mechanism of the refractoriness remains unclear. We compared the level of gastric acid suppression during PPI treatment between responders and non-responders by directly measuring gastric acid secretion in GERD patients taking PPIs.

METHODS

Seventy-five consecutive patients receiving standard-dose PPI therapy for GERD were prospectively recruited, irrespective of persistent GERD symptoms. They were asked about their GERD symptoms using a validated questionnaire, and simultaneously underwent both a routine endoscopic examination and a gastric acid secretory testing using an endoscopic gastrin test. Associations between residual gastric acid secretion during PPI treatment and persistent GERD symptoms were analyzed by a logistic regression analysis.

RESULTS

Overall, 26 of 75 (34.7%) patients were judged to be positive for persistent GERD symptoms. The patients with and without persistent symptoms showed similar gastric acid secretion levels (1.3 [1.3] mEq/10 min vs. 1.4 [2.0] mEq/10 min). Sufficient gastric acid suppression, defined as < 0.6, was not significantly associated with persistent GERD symptoms (odds ratio 1.1, 95% confidence interval 0.40-3.5).

CONCLUSIONS

This study provided solid evidence to support that the gastric acid suppression level during PPI treatment does not differ between patients with and without persistent GERD symptoms. The insignificant role of residual gastric acid in the persistent GERD symptoms suggests that the use of medications other than those that enhance gastric acid inhibitory effects would be an essential approach for the management of PPI-refractory GERD.

Clinicopathological significance of glomerular capillary IgA deposition in childhood IgA nephropathy

BACKGROUND

IgA nephropathy (IgAN) is characterized by predominant mesangial IgA deposition. Some patients with IgAN demonstrate IgA deposition in glomerular peripheral capillaries (cap-IgA). The clinicopathological significance of cap-IgA remains incompletely investigated in children.

METHODS

We retrospectively analyzed 503 consecutive cases of biopsy-proven childhood IgAN between July 1976 and June 2013 to compare clinical and pathological features between IgAN patients with and without cap-IgA.

RESULTS

Among the 503 patients, 30 (6.0%) had cap-IgA. We found significant differences in proteinuria (2.0 vs. 0.5 g/day/m², p < 0.0001), time from onset to kidney biopsy (2.2 vs. 8.3 months, p < 0.0001), and rate of proteinuria remission after treatment (23.3% vs. 48.0%, p = 0.007) between both groups. Pathological analysis revealed significant differences in M1 (83.3% vs. 56.0%, p = 0.002), ratio of subendothelial electron dense deposits (EDDs, 58.6% vs. 16.5%, p < 0.0001) and subepithelial EDDs (48.3% vs. 16.5%, p = 0.0001), and glomerular basement membrane (GBM) lysis (58.6% vs. 27.1%, p = 0.0006) between both groups. More than half of cap-IgA patients (17/30, 56.7%), whereas only 26.2% of non-cap-IgA patients (124/473), were treated with immunosuppressive treatments. Six of 30 cases (20%) with cap-IgA reached glomerular filtration rate (GFR) categories G3a-G5 (estimated GFR < 60 ml/min/1.73 m²) at most recent observation (mean observation period: 7.0 ± 4.0 years). According to Kaplan-Meier analysis, patients with cap-IgA had significantly lower kidney survival curves than non-cap-IgA patients (72.8% vs. 97.2% at 10 years, p < 0.0001).

CONCLUSIONS

Cap-IgA is associated with acute inflammation with GBM changes, resulting in refractory heavier proteinuria. Cap-IgA may represent a poor prognostic factor.

Study Design and Baseline Characteristics of the CARDINAL Trial: A Phase 3 Study of Bardoxolone Methyl in Patients with Alport Syndrome

INTRODUCTION

Alport syndrome is a rare genetic disorder that affects as many as 60,000 persons in the USA and a total of 103,000 persons (<5 per 10,000) in the European Union [1, 2]. It is the second most common inherited cause of kidney failure and is characterized by progressive loss of kidney function that often leads to end-stage kidney disease. Currently, there are no approved disease-specific agents for therapeutic use. We designed a phase 3 study (CARDINAL; NCT03019185) to evaluate the safety, tolerability, and efficacy of bardoxolone methyl in patients with Alport syndrome.

METHODS

The CARDINAL phase 3 study is an international, multicenter, double-blind, placebo-controlled, randomized registrational trial. Eligible patients were of ages 12-70 years with confirmed genetic or histologic diagnosis of Alport syndrome, eGFR 30-90 mL/min/1.73 m2, and urinary albumin to creatinine ratio (UACR) ≤3,500 mg/g. Patients with B-type natriuretic peptide values >200 pg/mL at baseline or with significant cardiovascular histories were excluded. Patients were randomized 1:1 to bardoxolone methyl or placebo, with stratification by baseline UACR.

RESULTS

A total of 371 patients were screened, and 157 patients were randomly assigned to receive bardoxolone methyl (n = 77) or placebo (n = 80). The average age at screening was 39.2 years, and 23 (15%) were <18 years of age. Of the randomized population, 146 (93%) had confirmed genetic diagnosis of Alport syndrome, and 62% of patients had X-linked mode of inheritance. Mean baseline eGFR was 62.7 mL/min/1.73 m2, and the geometric mean UACR was 141.0 mg/g. The average annual rate of eGFR decline prior to enrollment in the study was -4.9 mL/min/1.73 m2 despite 78% of the patient population receiving ACE inhibitor (ACEi) or ARB therapy.

DISCUSSION/CONCLUSION

CARDINAL is one of the largest interventional, randomized controlled trials in Alport syndrome conducted to date. Despite the use of ACEi or ARB, patients were experiencing significant loss of kidney function prior to study entry.

Genetic Analysis of UGT1A1 Polymorphisms Using Preserved Dried Umbilical Cord for Assessing the Potential of Neonatal Jaundice as a Risk Factor for Autism Spectrum Disorder in Children

Neonatal jaundice has been suggested as a perinatal risk factor for autism spectrum disorder (ASD). We examined UGT1A1 polymorphisms to assess the potential of neonatal jaundice as a risk factor for ASD in children by using DNA extracted from preserved umbilical cord. In total, 79 children with ASD were genotyped for UGT1A1*28 (c.-41-40dup), UGT1A1*6 (c.211 G > A), and UGT1A1*27 (c.686 C > A). The allele frequency of UGT1A1*6 (OR = 1.34, p = 0.26) and UGT1A1*28 (OR = 0.80, p = 0.54) and the prevalence of UGT1A1*28/*6 diplotypes did not differ significantly from those in the control population. No UGT1A1*27 allele was detected in the subjects. ASD symptom assessment scores were not associated with UGT1A1*28/*6/*27 genotypes or UGT1A1*28/*6 diplotypes. These results suggest that neonatal jaundice is not significantly associated with ASD.

Correction to: Functional analysis of suspected splicing variants in CLCN5 gene in Dent disease 1

A correction to this paper has been published: https://doi.org/10.1007/s10157-021-02041-8

Catheter-related blood stream infection caused by Mycobacterium chelonae in a child with myeloid leukemia associated with Down syndrome

Rapidly growing nontuberculous mycobacteria should be considered if GPRs gram-positive rods are detected in blood cultures 2-3 days after the blood sample collection.

A case of autoimmune enteropathy with CTLA4 haploinsufficiency

Autoimmune enteropathy (AIE) is a rare disease, characterized by intractable diarrhea, villous atrophy of the small intestine, and the presence of circulating anti-enterocyte autoantibodies. Immune dysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) syndrome, and mutations in FOXP3, which is a master gene of regulatory T cells (Tregs), are major causes of AIE. Recent studies have demonstrated that mutations in other Treg-associated genes, such as CD25 and CTLA4, show an IPEX-like phenotype. We present the case of a 13-year-old girl with CTLA4 haploinsufficiency, suffering from recurrent immune thrombocytopenic purpura and intractable diarrhea. We detected an autoantibody to the AIE-related 75 kDa antigen (AIE-75), a hallmark of the IPEX syndrome, in her serum. She responded well to a medium dose of prednisolone and a controlled dose of 6-mercaptopurine (6-MP), even after the cessation of prednisolone administration. Serum levels of the soluble interleukin-2 receptor and immunoglobulin G (IgG) were useful in monitoring disease activity during 6-MP therapy. In conclusion, autoimmune-mediated mechanisms, similar to the IPEX syndrome, may be involved in the development of enteropathy in CTLA4 haploinsufficiency. Treatment with 6-MP and monitoring of disease activity using serum levels of soluble interleukin-2 receptor and IgG is suggested for such cases.