A PEDIATRIC CASE OF PANNICULITIS INDUCED BY Pseudomonas aeruginosa WITH CLINICAL FEATURES SIMILAR TO ECTHYMA GANGRENOSUM.

The clinical features of panniculitis caused by Pseudomonas aeruginosa, in contrast to those caused by ecthyma gangrenosum, remain unknown. Here, we report a pediatric case of P. aeruginosa panniculitis. The patient had systemic involvement without bacteremia and also had a background of autoimmune neutropenia. These features are common in ecthyma gangrenosum but have not been reported in P. aeruginosa-induced panniculitis.

Impact of tracheostomies on the long-term survival of patients with trisomy 13 syndrome.

In this retrospective cohort study, we investigated the impact of tracheostomies on the long-term survival of children with trisomy 13 syndrome at a Japanese tertiary pediatric center. We compared survival and survival to discharge rates between patients who underwent tracheostomies during their NICU stays (T group, n = 8) and those who did not (non-T group, n = 11). A total of 19 patients enrolled. Median survival in all patients was 673 (266-1535) days. Significant differences in the 1-, 2-, and 3-year survival rates were found between the T and the non-T groups (100% vs. 46%, p = 0.018; 88% vs. 18%, p = 0.006; 63% vs. 9%, p = 0.041, respectively). The survival to discharge rate was higher in the T versus non-T group (75% vs. 45%, p = 0.352). This study highlights a significantly higher long-term survival of patients with trisomy 13 syndrome who underwent tracheostomies during their NICU stays.

International cohort of 382 children with lupus nephritis - presentation, treatment and outcome at 24 months.

BACKGROUND: Children with lupus have a higher chance of nephritis and worse kidney outcome than adult patients. METHODS: We retrospectively analyzed clinical presentation, treatment and 24-month kidney outcome in a cohort of 382 patients (≤ 18 years old) with lupus nephritis (LN) class ≥ III diagnosed and treated in the last 10 years in 23 international centers. RESULTS: The mean age at onset was 11 years 9 months and 72.8% were females. Fifty-seven percent and 34% achieved complete and partial remission at 24-month follow-up, respectively. Patients with LN class III achieved complete remission more often than those with classes IV or V (mixed and pure). Only 89 of 351 patients maintained stable complete kidney remission from the 6th to 24th months of follow-up. eGFR ≥ 90 ml/min/1.73 m2 at diagnosis and biopsy class III were predictive of stable kidney remission. The youngest and the oldest age quartiles (2y-9y, 5m) (14y, 2m-18y,2m) showed lower rates of stable remission (17% and 20.7%, respectively) compared to the two other age groups (29.9% and 33.7%), while there was no difference in gender. No difference in achieving stable remission was found between children who received mycophenolate or cyclophosphamide as induction treatment. CONCLUSION: Our data show that the rate of complete remission in patients with LN is still not high enough. Severe kidney involvement at diagnosis was the most important risk factor for not achieving stable remission while different induction treatments did not impact outcome. Randomized treatment trials involving children and adolescents with LN are needed to improve outcome for these children. A higher resolution version of the Graphical abstract is available as Supplementary information.

Efficacy of combination therapy for childhood complicated focal IgA nephropathy.

BACKGROUND: Patients with immunoglobulin A nephropathy who present with focal mesangial proliferation (focal IgAN) can have a relatively good prognosis, and renin-angiotensin system inhibitor (RAS-i) is commonly used as the initial treatment. However, there are some complicated focal IgAN cases with resistance to RAS-i treatment or nephrotic-range proteinuria. Thus, combination therapy including corticosteroids is often used. This study aimed to evaluate the efficacy of combination therapy for complicated focal IgAN cases by comparing to diffuse mesangial proliferation (diffuse IgAN). METHODS: We conducted a multicenter retrospective study on 88 children who received 2-year combination therapy. The participants were classified based on pathological severity: focal IgAN (n = 26) and diffuse IgAN (n = 62). RESULTS: In total, 26 patients with focal IgAN and 52 with diffuse IgAN achieved proteinuria disappearance within 2 years (100 vs. 83.9%, P = 0.03). Moreover, the time to proteinuria disappearance was significantly shorter in the focal IgAN group than in the diffuse IgAN group (2.9 vs. 4.2 months, P < 0.01) and all patients with focal IgAN achieved proteinuria disappearance within 8 months. At the last observation (8.6 vs. 10.4 years, P = 0.13), only patients with diffuse IgAN (n = 12) had greater than stage 2 chronic kidney disease. In terms of irreversible adverse events, one patient exhibited cataracts. CONCLUSION: Combination therapy was significantly effective in patients with complicated focal IgAN. Moreover, the long-term prognosis was good, and the duration of combination therapy for complicated focal IgAN can be decreased to reduce adverse events.

A Case with Iron Deficiency Anemia Developed Aplastic Crisis.

A toddler with an unbalanced diet and gastrointestinal bleeding by juvenile polyp developed an aplastic crisis due to the human parvovirus B19 (HPVB19). Although he exhibited microcytic anemia without iron deficiency in the acute phase of HPVB19 infection, he presented with iron deficiency anemia (IDA) in the chronic phase. IDA results in erythroblast hyperplasia and shortened red blood cell lifespan as like congenital hemolytic diseases, which may lead to an aplastic crisis during HPVB19 infection. It should be noted that iron deficiency is often masked, and microcytic anemia may be a clue for IDA.

Identification of novel OCRL isoforms associated with phenotypic differences between Dent disease-2 and Lowe syndrome.

BACKGROUND: Although Lowe syndrome and Dent disease-2 are caused by Oculocerebrorenal syndrome of Lowe (OCRL) mutations, their clinical severities differ substantially and their molecular mechanisms remain unclear. Truncating mutations in OCRL exons 1-7 lead to Dent disease-2, whereas those in exons 8-24 lead to Lowe syndrome. Herein we identified the mechanism underlying the action of novel OCRL protein isoforms. METHODS: Messenger RNA samples extracted from cultured urine-derived cells from a healthy control and a Dent disease-2 patient were examined to detect the 5' end of the OCRL isoform. For protein expression and functional analysis, vectors containing the full-length OCRL transcripts, the isoform transcripts and transcripts with truncating mutations detected in Lowe syndrome and Dent disease-2 patients were transfected into HeLa cells. RESULTS: We successfully cloned the novel isoform transcripts from OCRL exons 6-24, including the translation-initiation codons present in exon 8. In vitro protein-expression analysis detected proteins of two different sizes (105 and 80 kDa) translated from full-length OCRL, whereas only one protein (80 kDa) was found from the isoform and Dent disease-2 variants. No protein expression was observed for the Lowe syndrome variants. The isoform enzyme activity was equivalent to that of full-length OCRL; the Dent disease-2 variants retained >50% enzyme activity, whereas the Lowe syndrome variants retained <20% activity. CONCLUSIONS: We elucidated the molecular mechanism underlying the two different phenotypes in OCRL-related diseases; the functional OCRL isoform translated starting at exon 8 was associated with this mechanism.

Improving survival in patients with trisomy 18.

The effects of medical and surgical interventions on the survival of patients with trisomy 18 have been reported, leading to changes in perinatal management and decision-making. However, few studies have fully reported the recent changes in survival and treatment of trisomy 18. We examined how treatment and survival of patients with trisomy 18 have changed over a decade in a Japanese pediatric tertiary referral center. This retrospective cohort study included patients with trisomy 18 who were admitted within the first 7 days of life at the Hyogo Prefectural Kobe Children's Hospital between 2008 and 2017. The patients were divided into early period (EP) and late period (LP) groups based on the birth year of 2008-2012 and 2013-2017, respectively. Changes in treatment and survival rates were compared between the two groups. A total of 56 patients were studied (29 in the EP group and 27 in the LP group). One-year survival rates were 34.5% and 59.3% in the EP and LP groups, respectively. The survival to discharge rate significantly increased from 27.6% in the EP group to 81.5% in the LP group (p < 0.001). The proportion of patients receiving surgery, especially for congenital heart defects, significantly increased from 59% in the EP group to 96% in the LP group (p = 0.001). In our single-center study, survival and survival to discharge were significantly improved in patients with trisomy 18, probably because of increased rate of surgical interventions. These findings may facilitate better decision-making by patients' families and healthcare providers.

Bilateral Renal Hypoplasia with High ß2-Microglobulinuria in the Neonatal Period.

Urinary ß2 microglobulin (ß2-MG) is a low-molecular-weight protein that is filtered by the glomerular basement membrane and absorbed by the proximal tubule epithelial cells. In perinatal management, urinary ß2-MG levels are used to assess intrauterine inflammation in newborns, since urinary excretion increases during inflammation. Furthermore, ß2-MG levels in fetal blood and urine are also used for predicting fetal renal function because ß2-MG is not transferred to the placenta. Herein, we reported a patient with persistent high urinary ß2-MG levels since neonatal period, who was later diagnosed with bilateral renal hypoplasia. If a newborn presents persistent hyper ß2-microglobulinuria even without hematuria or proteinuria, congenital renal malformations should be considered.

X-chromosome inactivation patterns in females with Fabry disease examined by both ultra-deep RNA sequencing and methylation-dependent assay.

BACKGROUND: Fabry disease is an X-linked inherited lysosomal storage disorder caused by mutations in the gene encoding α-galactosidase A. Males are usually severely affected, while females have a wide range of disease severity. This variability has been assumed to be derived from organ-dependent skewed X-chromosome inactivation (XCI) patterns in each female patient. Previous studies examined this correlation using the classical methylation-dependent method; however, conflicting results were obtained. This study was established to ascertain the existence of skewed XCI in nine females with heterozygous pathogenic variants in the GLA gene and its relationship to the phenotypes. METHODS: We present five female patients from one family and four individual female patients with Fabry disease. In all cases, heterozygous pathogenic variants in the GLA gene were detected. The X-chromosome inactivation patterns in peripheral blood leukocytes and cells of urine sediment were determined by both classical methylation-dependent HUMARA assay and ultra-deep RNA sequencing. Fabry Stabilization Index was used to determine the clinical severity. RESULTS: Skewed XCI resulting in predominant inactivation of the normal allele was observed only in one individual case with low ⍺-galactosidase A activity. In the remaining cases, no skewing was observed, even in the case with the highest total severity score (99.2%). CONCLUSION: We conclude that skewed XCI could not explain the severity of female Fabry disease and is not the main factor in the onset of various clinical symptoms in females with Fabry disease.

Comparison of clinical and genetic characteristics between Dent disease 1 and Dent disease 2.

BACKGROUND: Dent disease is associated with low molecular weight proteinuria and hypercalciuria and caused by pathogenic variants in either of two genes: CLCN5 (Dent disease 1) and OCRL (Dent disease 2). It is generally not accompanied by extrarenal manifestations and it is difficult to distinguish Dent disease 1 from Dent disease 2 without gene testing. We retrospectively compared the characteristics of these two diseases using one of the largest cohorts to date. METHODS: We performed gene testing for clinically suspected Dent disease, leading to the genetic diagnosis of 85 males: 72 with Dent disease 1 and 13 with Dent disease 2. A retrospective review of the clinical findings and laboratory data obtained from questionnaires submitted in association with the gene testing was conducted for these cases. RESULTS: The following variables had significantly higher levels in Dent disease 2 than in Dent disease 1: height standard deviation score (height SDS), serum creatinine-based estimated GFR (Cr-eGFR) (median: 84 vs. 127 mL/min/1.73 m2, p < 0.01), serum aspartate aminotransferase (AST), serum alanine aminotransferase (ALT), serum lactate dehydrogenase (LDH), serum creatine phosphokinase (CK), serum potassium, serum inorganic phosphorus, serum uric acid, urine protein/creatinine ratio (median: 3.5 vs. 1.6 mg/mg, p < 0.01), and urine calcium/creatinine ratio. There were no significant differences in serum sodium, serum calcium, alkaline phosphatase (ALP), urine ß2-microglobulin, incidence of nephrocalcinosis, and prevalence of intellectual disability or autism spectrum disorder. CONCLUSIONS: The clinical and laboratory features of Dent disease 1 and Dent disease 2 were shown in this study. Notably, patients with Dent disease 2 showed kidney dysfunction at a younger age, which should provide a clue for the differential diagnosis of these diseases.

Pathogenic evaluation of synonymous COL4A5 variants in X-linked Alport syndrome using a minigene assay.

BACKGROUND: X-linked Alport syndrome (XLAS) is a progressive, hereditary glomerular nephritis of variable severity caused by pathogenic COL4A5 variants. Currently, genetic testing is widely used for diagnosing XLAS; however, determining the pathogenicity of variants detected by such analyses can be difficult. Intronic variants or synonymous variants may cause inherited diseases by inducing aberrant splicing. Transcript analysis is necessary to confirm the pathogenicity of such variants, but it is sometimes difficult to extract mRNA directly from patient specimens. METHODS: In this study, we conducted in vitro splicing analysis using a hybrid minigene assay and specimens from three XLAS patients with synonymous variants causing aberrant splicing, including previously reported pathogenic mutations in the same codon. The variants were c.876 A>T (p.Gly292=), c.2358 A>G (p.Pro786=), and c.3906 A>G (p.Gln1302=). RESULTS: The results from our hybrid minigene assay were sufficient to predict splicing abnormalities; c.876 A>T cause 17-bp del and 35-bp del, c.2358 A>G cause exon 29 skipping, c.3906 A>G cause exon 42 skipping, which are very likely to cause pathogenicity. Further, patients carrying c.2358 A>G exhibited a mild phenotype that may have been associated with the presence of both normal and abnormally spliced transcripts. CONCLUSION: The minigene system was shown to be a sensitive assay and a useful tool for investigating the pathogenicity of synonymous variants.

Development of an exon skipping therapy for X-linked Alport syndrome with truncating variants in COL4A5.

Currently, there are no treatments for Alport syndrome, which is the second most commonly inherited kidney disease. Here we report the development of an exon-skipping therapy using an antisense-oligonucleotide (ASO) for severe male X-linked Alport syndrome (XLAS). We targeted truncating variants in exon 21 of the COL4A5 gene and conducted a type IV collagen α3/α4/α5 chain triple helix formation assay, and in vitro and in vivo treatment efficacy evaluation. We show that exon skipping enabled trimer formation, leading to remarkable clinical and pathological improvements including expression of the α5 chain on glomerular and the tubular basement membrane. In addition, the survival period was clearly prolonged in the ASO treated mice group. This data suggests that exon skipping may represent a promising therapeutic approach for treating severe male XLAS cases.

Gastrointestinal symptoms as an extended clinical feature of Pierson syndrome: a case report and review of the literature.

BACKGROUND: Pierson syndrome (PS) is a rare autosomal recessive disorder, characterized by congenital nephrotic syndrome and microcoria. Advances in renal replacement therapies have extended the lifespan of patients, whereas the full clinical spectrum of PS in infancy and beyond remains elusive. CASE PRESENTATION: We present the case of a 12-month-old boy with PS, manifesting as the bilateral microcoria and congenital nephrotic syndrome. He was born without asphyxia, and was neurologically intact from birth through the neonatal period. Generalized muscle weakness and hypotonia were recognized from 3 months of age. The infant showed recurrent vomiting at age 5 months of age, and was diagnosed with gastroesophageal reflux and intestinal malrotation. Despite the successful surgical treatment, vomiting persisted and led to severely impaired growth. Tulobuterol treatment was effective in reducing the frequency of vomiting. Targeted sequencing confirmed that he had a compound heterozygous mutation in LAMB2 (NM_002292.3: p.Arg550X and p.Glu1507X). A search of the relevant literature identified 19 patients with severe neuro-muscular phenotypes. Among these, only 8 survived the first 12 months of life, and one had feeding difficulty with similar gastrointestinal problems. CONCLUSIONS: This report demonstrated that severe neurological deficits and gastrointestinal dysfunction may emerge in PS patients after the first few months of life.

Clinical and genetic variability of PAX2-related disorder in the Japanese population.

Pathogenic variants of paired box gene 2 (PAX2) cause autosomal-dominant PAX2-related disorder, which includes renal coloboma syndrome (RCS). Patients with PAX2-related disorder present with renal and ophthalmological pathologies, as well as with other abnormalities, including developmental problems and hearing loss. We sequenced PAX2 in 457 patients with congenital anomalies of the kidney and urinary tract or with renal dysfunction of unknown cause and identified 19 different pathogenic variants in 38 patients from 30 families (6.5%). Thirty-four patients had renal hypodysplasia or chronic kidney disease of unknown cause, and three had focal segmental glomerulosclerosis. Although no obvious genotype-phenotype correlation was observed, six of the seven patients who developed end-stage renal disease in childhood had truncating variants. Twenty-three patients had ocular disabilities, mostly optic disc coloboma. Non-renal and non-ophthalmological manifestations included developmental disorder, electrolyte abnormality, and gonadal abnormalities. Two unrelated patients had congenital cystic adenomatoid malformations in their lungs. Six of ten probands with PAX2 mutation identified by next-generation sequencing did not show typical RCS manifestations. We conclude that PAX2-related disorder has a variable clinical presentation and can be diagnosed by next-generation sequencing even in the absence of typical RCS manifestations.

Molecular mechanisms determining severity in patients with Pierson syndrome.

Null variants in LAMB2 cause Pierson syndrome (PS), a severe congenital nephrotic syndrome with ocular and neurological defects. Patients' kidney specimens show complete negativity for laminin ß2 expression on glomerular basement membrane (GBM). In contrast, missense variants outside the laminin N-terminal (LN) domain in LAMB2 lead to milder phenotypes. However, we experienced cases not showing these typical genotype-phenotype correlations. In this paper, we report six PS patients: four with mild phenotypes and two with severe phenotypes. We conducted molecular studies including protein expression and transcript analyses. The results revealed that three of the four cases with milder phenotypes had missense variants located outside the LN domain and one of the two severe PS cases had a homozygous missense variant located in the LN domain; these variant positions could explain their phenotypes. However, one mild case possessed a splicing site variant (c.3797 + 5G>A) that should be associated with a severe phenotype. Upon transcript analysis, this variant generated some differently sized transcripts, including completely normal transcript, which could have conferred the milder phenotype. In one severe case, we detected the single-nucleotide substitution of c.4616G>A located outside the LN domain, which should be associated with a milder phenotype. However, we detected aberrant splicing caused by the creation of a novel splice site by this single-base substitution. These are novel mechanisms leading to an atypical genotype-phenotype correlation. In addition, all four cases with milder phenotypes showed laminin ß2 expression on GBM. We identified novel mechanisms leading to atypical genotype-phenotype correlation in PS.