Changes in awareness and knowledge concerning mother-to-child infections among Japanese pregnant women between 2012 and 2018

This study aimed to investigate the long-term changes in awareness of and knowledge about mother-to-child infections across 6 years in Japan. A questionnaire survey was conducted at our facility from October 2012 to January 2018, and the study periods were divided into 4 phases comprising 16 months each. A multiple-choice questionnaire assessed participants’ awareness of the following 13 pathogens of mother-to-child infections: cytomegalovirus (CMV), Toxoplasma gondii (T. gondii), hepatitis B virus, rubella virus, herpes simplex virus, parvovirus B19, hepatitis C virus, human immunodeficiency virus, human T cell leukemia virus type-1, measles virus, varicella-zoster virus, Chlamydia trachomatis, and Treponema pallidum. For the selected four pathogens (i.e., CMV, rubella virus, T. gondii, and parvovirus B19), the questionnaire also evaluated participants’ knowledge of transmission routes, the most susceptible time of infection that could yield severe fetal disease during pregnancy, the maximum frequency of fetal infection in cases of maternal infection, and methods to prevent maternal infection. In total, 1433 pregnant Japanese women were included in this study. There was no secular change in awareness of the pathogens concerning mother-to-child infections over time, and we also clarified that the detailed knowledge of the four pathogens of typical mother-to-child infections did not improve. Since knowledge about methods to prevent maternal infection is still insufficient for all pathogens, further advocacy is required to prevent mother-to-child infections.

Genetic background, recent advances in molecular biology, and development of novel therapy in Alport syndrome

Alport syndrome (AS) is a progressive inherited kidney disease characterized by hearing loss and ocular abnormalities. There are three forms of AS depending on inheritance mode: X-linked Alport syndrome (XLAS), autosomal recessive AS (ARAS), and autosomal dominant AS (ADAS). XLAS is caused by pathogenic variants in COL4A5, which encodes type IV collagen α5 chain, while ADAS and ARAS are caused by variants in COL4A3 or COL4A4, which encode type IV collagen α3 or α4 chain, respectively. In male XLAS or ARAS cases, end-stage kidney disease (ESKD) develops around a median age of 20 to 30 years old, while female XLAS or ADAS cases develop ESKD around a median age of 60 to 70 years old. The diagnosis of AS is dependent on either genetic or pathological findings. However, determining the pathogenicity of the variants detected by gene tests can be difficult. Recently, we applied the following molecular investigation tools to determine pathogenicity: 1) in silico and in vitro trimer formation assay of α345 chains to assess triple helix formation ability, 2) kidney organoids constructed from patients’ induced pluripotent stem cells to identify α5 chain expression on the glomerular basement membrane, and 3) in vitro splicing assay to detect aberrant splicing to determine the pathogenicity of variants. In this review article, we discuss the genetic background and novel assays for determining the pathogenicity of variants. We also discuss the current treatment approaches and introduce exon skipping therapy as one potential treatment option.

Autosomal Dominant Tubulointerstitial Kidney Disease HNF1B With Maturity-Onset Diabetes of the Young: A Case Report With Kidney Biopsy

Autosomal dominant tubulointerstitial kidney disease subtype hepatocyte nuclear factor 1β (ADTKD-HNF1B) is a hereditary disease caused by variants of HNF1B that is characterized by a family history of tubulointerstitial nephropathy with concomitant diabetes mellitus. We report on a Japanese man in his early 40s who had ADTKD-HNF1B diagnosed. He had a reduced glomerular filtration rate, borderline diabetes mellitus, multiple small cysts in his bilateral kidneys, and pancreatic hypoplasia. He also had a family history of diabetes and kidney cystic lesions. These phenotypes represent ADTKD-HNF1B and genetic analysis revealed a missense variant of HNF1B. Kidney biopsy demonstrated not only tubulointerstitial fibrosis but also abnormal mitochondrial morphology in tubular cells, a novel finding.

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 β2-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.

Extranodal natural killer/T-cell lymphoma in an 11-year-old child

Extranodal natural killer/T-cell lymphoma (ENKTL) is difficult to identify and diagnose appropriately. Positron emission tomography imaging is a crucial method that leads to precise diagnosis. A proper regimen including stem cell transplantation would possibly improve prognosis of advanced ENKTL.

Genetic analysis diagnosed Bardet–Biedl syndrome in a patient with a clinical diagnosis of Senior–Løken syndrome

Background

Senior–Løken syndrome (SLS) and Bardet–Biedl syndrome (BBS) are ciliopathies. SLS is characterized by retinitis pigmentosa (RP) and familial nephronophthisis, leading to end-stage kidney disease, while BBS is characterized by six major symptoms: RP, polydactyly, obesity, genital abnormalities, learning difficulties, and renal defects. Ciliopathies have been diagnosed on a phenotypic basis, but diagnosis can now be established by genetic testing, using techniques such as next-generation sequencing. Here, we report a patient clinically diagnosed with SLS but diagnosed with BBS 13 years later using next-generation sequencing.

Case presentation

The patient was diagnosed with RP at the age of 6 years. She had some difficulty in social interactions and pre-obesity, but no polydactyly. At the age of 8 years, she was diagnosed with chronic kidney disease, anemia, and liver dysfunction. Kidney and liver biopsy revealed renal tubule cysts, tubule membrane disruption, and liver fibrosis. Therefore, SLS was diagnosed but no NPHP1 mutations were detected. Peritoneal dialysis was started at the age of 9 years, and she underwent kidney transplantation with a graft from her father at the age of 13 years. At the age of 21 years, she again underwent genetic testing for most of the mutations associated with ciliopathy. This revealed a homozygous frameshift mutation in intron 11 of SDCCAG8.

Conclusions

Mutations in SDCCAG8 are known to be causative of SLS and BBS without polydactyly. The fact that the patient had RP, some difficulty in social interactions, pre-obesity, juvenile nephronophthisis, liver fibrosis, bronchial asthma, and otitis media suggested BBS. However, some of these are not specific symptoms for BBS and she had few typical symptoms of BBS. Therefore, a definitive diagnosis of BBS was difficult without genetic analysis. Because many more patients with SDCCAG8 mutations have extrarenal manifestations like the current patient than standard nephronophthisis patients, careful monitoring of extrarenal manifestations is needed to improve patient management.

A woman with a dual genetic diagnosis of autosomal dominant tubulointerstitial kidney disease and KBG syndrome

We present a female patient with a dual genetic diagnosis of autosomal dominant tubulointerstitial kidney disease and KBG syndrome. The proband was an 18-year-old woman presenting with intellectual disability, renal insufficiency, and hyperuricemia. Abdominal ultrasonography did not reveal any abnormalities. The patient's father had been diagnosed with chronic kidney disease and hyperuricemia in his twenties; however, he had no intellectual disability. Her mother and two younger siblings were not affected. Next generation sequencing (NGS) identified mutations in UMOD (c.796T > C) of the proband and her father, and in ANKRD11 (c.1903_1907del) of the proband. Renal insufficiency and intellectual disability were attributed to mutations in UMOD and ANRKD11, respectively. When making genetic diagnoses, the presence of multiple mutations in an individual should be considered, particularly when not all symptoms could be attributed to a single disease. The number of patients with dual genetic diagnosis is expected to increase as NGS becomes more readily available; thus, making it necessary to undertake a careful and robust assessment of the clinical symptoms and the related genotypes, to ensure an accurate diagnosis.

Elevated cytokine, chemokine, and growth and differentiation factor-15 levels in hemorrhagic shock and encephalopathy syndrome: A retrospective observational study

Patients with hemorrhagic shock and encephalopathy syndrome (HSES) have a high early mortality rate, which may be caused by a 'cytokine storm'. However, there is little information on how cytokines and chemokines change over time in these patients. We aimed to describe the characteristics of HSES by examining changes in serum biomarker levels over time. Six patients with HSES were included. We retrospectively evaluated their clinical course and imaging/laboratory data. We measured serum levels of multiple cytokines [interleukin 1β (IL-1β), IL-2, IL-4, IL-6, IL-10, IL-17, interferon-gamma, and tumor necrosis factor alpha], chemokines (IL-8, monocyte chemoattractant protein-1, interferon-inducible protein-10), and growth and differentiation factor (GDF)-15. The highest cytokine and chemokine levels were noted in the first 24 h, and decreased thereafter. The GDF-15 level was markedly high. Cytokine, chemokine, and GDF-15 levels were significantly higher in patients with HSES than in controls in the first 24 h, except for IL-2 and IL-4. Patients with HSES have high inflammatory cytokine and chemokine levels, a high GDF-15 level in the first 24 h, and high lactate levels. Our study provides new insights on the pathophysiology of HSES, a detailed clinical picture of patients with HSES, and potential biomarkers.

Frailty Checkup Supporters' Intentions to Participate in Human-Resource Development and Training Activities

BACKGROUND

Frailty prevention is one of social prescriptions for an aging society. That requires community level intervention.

OBJECTIVES

This study examined frailty checkup supporters' (FCSs') intentions to engage in human-resource development and training activities (i.e., leadership activities) and related factors.

DESIGN

Cross-sectional study.

SETTING

Three municipalities in suburban area, Eastern Japan.

PARTICIPANTS

Forty-five of 59 FCSs completed anonymous self-administered questionnaires.

MEASUREMENTS

Questionnaire sought information regarding their sociodemographic data, their perceptions and experiences of FCS activities, and their intentions to participate in human-resource development and training activities. Participants were divided into a high intention (HI) and low intention group (LI). The two groups were compared using quantitative and qualitative data.

RESULTS

Eleven FCSs reported intending to engage in leader-related activities. Factors associated with FCSs' intentions were finding FCS activities rewarding and the willingness to continue performing FCS activities. The participants who changed their daily activities (p = .041) and perceptions regarding contributing to the community (p = .018) showed significantly higher intention than LI participants. Free description about the changes in perceptions and lifestyles as a consequence of participating in FCS activities were analyzed qualitatively. FCSs who changed their daily activities and perspectives about contributing to the community described positive changes in both the groups. Meanwhile, FCSs who did not change their daily activities and perspectives about contributing to the community described their reason only in the LI group.

CONCLUSIONS

The results might encourage FCSs to participate in training and guidance activities, as they have positive experiences and receive recognition obtained through participation in such activities.

Biallelic variants/mutations of IL1RAP in patients with steroid-sensitive nephrotic syndrome

Nephrotic syndrome (NS) is a renal disease characterized by severe proteinuria and hypoproteinemia. Although several single-gene mutations have been associated with steroid-resistant NS, causative genes for steroid-sensitive NS (SSNS) have not been clarified. While seeking to identify causative genes associated with SSNS by whole-exome sequencing, we found compound heterozygous variants/mutations (c.524T>C; p.I175T and c.662G>A; p.R221H) of the interleukin-1 receptor accessory protein (IL1RAP) gene in two siblings with SSNS. The siblings' parents are healthy, and each parent carries a different heterozygous IL1RAP variant/mutation. Since IL1RAP is a critical subunit of the functional interleukin-1 receptor (IL-1R), we investigated the effect of these variants on IL-1R subunit function. When stimulated with IL-1β, peripheral blood mononuclear cells from the siblings with SSNS produced markedly lower levels of cytokines compared with cells from healthy family members. Moreover, IL-1R with a variant IL1RAP subunit, reconstituted on a hematopoietic cell line, had impaired binding ability and low reactivity to IL-1β. Thus, the amino acid substitutions in IL1RAP found in these NS patients are dysfunctional variants/mutations. Furthermore, in the kidney of Il1rap-/- mice, the number of myeloid-derived suppressor cells, which require IL-1β for their differentiation, was markedly reduced although these mice did not show significantly increased proteinuria in acute nephrotic injury with lipopolysaccharide treatment. Together, these results identify two IL1RAP variants/mutations in humans for the first time and suggest that IL1RAP might be a causative gene for familial NS.

Heterozygous Urinary Abnormality-Causing Variants of COL4A3 and COL4A4 Affect Severity of Autosomal Recessive Alport Syndrome

Background

Autosomal recessive Alport syndrome (ARAS) is an inherited renal disorder caused by homozygous and compound heterozygous mutations in COL4A3 or COL4A4, but the prognostic predictors for this disorder are not yet fully understood. Recently, the magnitude of the clinical spectrum of the COL4A3 and COL4A4 heterozygous state has attracted attention. This spectrum includes asymptomatic carriers of ARAS, benign familial hematuria, thin basement membrane disease, and autosomal dominant Alport syndrome.

Methods

We retrospectively analyzed 49 patients with ARAS from 41 families with a median age of 19 years to examine the clinical features and prognostic factors of ARAS, including the associated genotypes.

Results

The median age of patients with ARAS at ESKD onset was 27 years. There was no significant association between the presence or absence of hearing loss or truncating mutations and renal prognosis. However, there was a statistically significant correlation between renal prognosis and heterozygous variants that cause urinary abnormalities. Where the urinary abnormality-causing variant was absent or present in only one allele, the median age of ESKD onset was 45 years, whereas the same variant present on both alleles was associated with an age of onset of 15 years (P<0.001).

Conclusions

This study was the first to demonstrate the clinical importance in ARAS of focusing on variants in COL4A3 or COL4A4 that cause urinary abnormalities in both the homozygous or heterozygous state. Although heterozygous mutation carriers of COL4A3 and COL4A4 comprise a broad clinical spectrum, clinical information regarding each variant is important for predicting ARAS prognosis.

A Novel Method for Measuring Serum Unbound Bilirubin Levels Using Glucose Oxidase-Peroxidase and Bilirubin-Inducible Fluorescent Protein (UnaG): No Influence of Direct Bilirubin

The glucose oxidase–peroxidase (GOD–POD) method used to measure serum unbound bilirubin (UB) suffers from direct bilirubin (DB) interference. Using a bilirubin-inducible fluorescent protein from eel muscle (UnaG), a novel GOD–POD–UnaG method for measuring UB was developed. Newborn sera with an indirect bilirubin/albumin (iDB/A) molar ratio of <0.5 were classified into four groups of DB/total serum bilirubin (TB) ratios (<5%, 5–10%, 10–20%, and ≥20%), and the correlation between the UB levels and iDB/A ratio was examined. Linear regression analysis was performed to compare UB values from both methods with the iDB/A ratio from 38 sera samples with DB/TB ratio <5% and 11 samples with DB/TB ratio ≥5%. The correlation coefficient (r) between UB values and the iDB/A ratio for the GOD–POD method was 0.8096 (DB/TB ratio <5%, n = 239), 0.7265 (5–10%, n = 29), 0.7165 (10–20%, n = 17), and 0.4816 (≥20%, n = 16). UB values using the GOD–POD–UnaG method highly correlated with the iDB/A ratio in both <5% and ≥5% DB/TB ratio sera (r = 0.887 and 0.806, respectively), whereas a low correlation (r = 0.428) occurred for ≥5% DB/TB ratio sera using the GOD–POD method. Our GOD–POD–UnaG method can measure UB levels regardless of the presence of DB.

Seizure prevalence in children aged up to 3 years: a longitudinal population-based cohort study in Japan

OBJECTIVE

To investigate the prevalence of seizures/febrile seizures in children up to 3 years of age and examine the effects of gestational age at birth on the risk for febrile seizures.

DESIGN

Retrospective longitudinal population-based cohort study.

SETTING

Kobe City public health center, Kobe, Japan, from 2010 to 2018.

PARTICIPANTS

Children who underwent a medical check-up at 3 years of age.

METHODS

Information regarding seizures was collected from the parents of 96 014 children. We identified the occurrence of seizure/febrile seizure in 74 017 children, whose gestational ages at birth were noted. We conducted a multivariate analysis with the parameter, gestational age at birth, to analyse the risk of seizure. We also stratified the samples by sex and birth weight (<2500 g or not) and compared the prevalence of seizure between those with the term and late preterm births.

RESULTS

The prevalence of seizure was 12.1% (11.8%-12.3%), 13.2% (12.2%-14.4%), 14.6% (12.4%-17.7%) and 15.7% (10.5%-22.8%) in children born at 37-41, 34-36, 28-33 and 22-27 gestational weeks, respectively. The prevalence of febrile seizures was 9.0% (8.8%-9.2%), 10.5% (9.5%-11.5%), 11.8% (9.7%-14.5%) and 11.2% (6.9%-17.7%) in children born at 37-41, 34-36, 28-33 and 22-27 gestational weeks, respectively. Male was an independent risk factor for seizures (OR: 1.15, 95% CI 1.09 to 1.20; absolute risk increase 0.014, 95% CI 0.010 to 0.019) and febrile seizures (OR: 1.21, 95% CI 1.15 to 1.28; absolute risk increase 0.016, 95% CI 0.012 to 0.020), respectively. Late preterm birth was not associated with an increased risk of seizure/febrile seizure.

CONCLUSIONS

Although very preterm birth may increase the risk of seizure/febrile seizure, the risk associated with late preterm birth is considerably small and less than that associated with male.

FAT1 biallelic truncating mutation causes a non-syndromic proteinuria in a child

The identification of monogenic causes in patients with proteinuria has revealed that the encoded proteins functionally participate in distinct cellular tasks and signaling pathways in the slit diaphragms of the glomerular basement membrane. FAT1 is a member of a small family of vertebrate-cadherin-like genes, which is a crucial component in slit diaphragms and has a vital role in tubular regeneration. Only 5 cases with glomerulonephritis having FAT1 gene biallelic variants have been reported. However, only one had the biallelic truncating variant, and others had missense variants. Therefore, we need further evidence of this gene being responsible for steroid-resistant nephrotic syndrome (SRNS) or glomerulonephritis. Here we describe a 5-year-old boy in who proteinuria was detected at the age of 3 years without any extrarenal symptom. The pathological findings were examined, and targeted exome sequencing was performed. We also conducted reviews for all previously-reported cases of glomerulonephritis possessing FAT1 biallelic gene variants. We found two novel truncating variants in FAT1 (NM_005245.3), c.12867dup in exon 10, and, c.5480_5483del in exon 25. Our case showed mild proteinuria compared to previously-reported cases who showed SRNS and extrarenal symptoms that might have been because the latter variant in our patient was located on out of cadherin domains; however, our follow up period is short and we further need careful follow up. Our findings corroborate the evidence that individuals with FAT1-truncating variants can show isolated mild proteinuria. Further studies are needed to investigate the genotype-phenotype correlation in this disease. Therefore, our case will provide vital information regarding this rare condition.

Immune-complex glomerulonephritis with a membranoproliferative pattern in Frasier syndrome: a case report and review of the literature

Background

Mutations in the Wilms tumor 1 gene cause a spectrum of podocytopathy ranging from diffuse mesangial sclerosis to focal segmental glomerulosclerosis. In a considerable fraction of patients with Wilms tumor 1 mutations, the distinctive histology of immune-complex-type glomerulonephritis has been reported. However, the clinical relevance and etiologic mechanisms remain unknown.

Case presentation

A 5-year-old child presented with steroid-resistant nephrotic range proteinuria. Initial renal biopsy revealed predominant diffuse mesangial proliferation with a double-contour and coexisting milder changes of focal segmental glomerulosclerosis. Immunofluorescence and electron microscopy revealed a full-house-pattern deposition of immune complexes in the subendothelial and paramesangial areas. Serial biopsies at 6 and 8 years of age revealed that more remarkable changes of focal segmental glomerulosclerosis had developed on top of the initial proliferative glomerulonephritis. Identification of a de novo Wilms tumor 1 splice donor-site mutation in intron 9 (NM_024426.6:c.1447 + 4C > T) and 46,XY-gonadal dysgenesis led to the diagnosis of Frasier syndrome.

Conclusions

Our findings, together with those of others, point to the importance of heterogeneity in clinicopathological phenotypes caused by Wilms tumor 1 mutations and suggest that immune-complex-mediated membranoproliferative glomerulopathy should be considered as a histological variant.

A cross-sectional nationwide survey of congenital and infantile nephrotic syndrome in Japan

BACKGROUND

Congenital nephrotic syndrome (CNS) and infantile nephrotic syndrome (INS) cause substantial morbidity and mortality. In Japan, there is a lack of knowledge regarding the characteristics of CNS and INS. This study aimed to clarify the characteristics of CNS and INS in Japan.

METHODS

This cross-sectional nationwide survey obtained data from 44 institutions in Japan managing 92 patients with CNS or INS, by means of two survey questionnaires sent by postal mail. Patients aged < 16 years by 1 April 2015, with a diagnosis of CNS or INS, were included in this study. The primary outcome was end-stage kidney disease.

RESULTS

A total of 83 patients with CNS or INS were analyzed. The most frequent disease type was non-Finnish (60.2%); 33 patients (39.8%) had Finnish type. Among those with non-Finnish-type disease, 26 had no syndrome and 24 had a syndrome, of which the most frequent was Denys-Drash syndrome (70.8%). Patients with non-Finnish-type disease with syndrome showed the earliest progression to end-stage kidney disease compared with the other two groups, whereas patients with non-Finnish-type disease without syndrome progressed more slowly compared with the other two groups. In the Finnish-type group, the disease was diagnosed the earliest; a large placenta was reported more frequently; genetic testing was more frequently performed (93.8%); mental retardation was the most frequent extra-renal symptom (21.2%); and thrombosis and infection were more frequent compared with the other groups. Patients with non-Finnish-type disease with syndrome had a higher frequency of positive extra-renal symptoms (79.2%), the most common being urogenital symptoms (54.2%). Treatment with steroids and immunosuppressants was more frequent among patients with non-Finnish-type disease without syndrome. Two patients with non-Finnish-type disease without syndrome achieved complete remission. In all groups, unilateral nephrectomy was performed more often than bilateral nephrectomy and peritoneal dialysis was the most common renal replacement therapy.

CONCLUSIONS

The present epidemiological survey sheds light on the characteristics of children with CNS and INS in Japan. A high proportion of patients underwent genetic examination, and patient management was in accord with current treatment recommendations and practices.

TRIAL REGISTRATION

Not applicable.

A Japanese boy with NAA10-related syndrome and hypertrophic cardiomyopathy

NAA10-related syndrome is an extremely rare X-chromosomal disorder, the symptoms of which include intellectual disability (ID), ocular anomalies, or congenital heart diseases, such as hypertrophic cardiomyopathy (HCM). Here, we describe a 4-year-old Japanese male patient who exhibited mild ID, HCM, and specific facial features. A hemizygous mutation (NM_003491.3: c.455_458del, p. Thr152Argfs*6) in exon 7 of NAA10 was detected. We recommend that patients undergo precise medical follow-up considering the characteristics of NAA10-related syndrome.

False positive cases of elevated tetradecenoyl carnitine in newborn mass screening showed significant loss of body weight

Very-long-chain acyl-CoA dehydrogenase (VLCAD) deficiency, a condition in which the body is unable to break down long-chain fatty acids properly, is the most common fatty acid oxidation disorder in Japan. Tandem mass spectrometry has been used in newborn screening (NBS), allowing the detection of patients with VLCAD deficiency even before symptoms manifest. However, tandem mass spectrometry has a high false positive rate. We investigated the clinical characteristics of patients with false positive results for tetradecenoyl acylcarnitine (C14:1). This case-control study used data collected between the 1st of January 2014 and the 31st of March 2019. The case group was defined as patients having levels of both C14:1 and C14:1/C2 ratio higher than cut-off levels in the first newborn mass screening, who were eventually diagnosed as false positives by attending doctors at Kobe University Hospital, Palmore Hospital, or Kakogawa Central City Hospital in Japan. The control group comprised 100 patients randomly selected from the three facilities. The false positive group included 17 cases, and the control group contained 300 patients. The demographics of each group did not show any significant differences in sex, body weight at birth, Cesarean section rate, complete breastfeeding rate, or the number of feedings per day. However, the change in body weight at the sampling day of NBS in the false positive and control groups was -10.2%, and - 4.6%, respectively, showing a statistically significant difference (p < 0.01). In addition, body weight gain at the one-month medical checkup was 38.9 g/day in the false positive group and 44.1 g/day in the control group (p < 0.05). An elevation of C14:1 carnitine has been reported in situations involving the catalysis of fatty acid. Therefore, patients with severe body weight loss might be associated with poor sucking or poor milk supply, which might cause a false positive elevation of C14:1 and C14:1/C2. In suspected VLCAD deficiency, attending doctors should pay attention to body weight changes recorded during newborn mass screening.

Genotype-phenotype correlations influence the response to angiotensin-targeting drugs in Japanese patients with male X-linked Alport syndrome

Early kidney failure in the hereditary type IV collagen disease, Alport syndrome, can be delayed by renin-angiotensin inhibitors. However, whether all patients and all different genotypes respond equally well to this kidney-protective therapy remains unclear. Here, we performed a retrospective study on 430 patients with male X-linked Alport syndrome to examine the relationships among kidney prognosis, genotype, and treatment effect in a large cohort of Japanese patients. We analyzed the clinical features, genotype-phenotype correlation, and kidney survival period for patients treated with or without renin-angiotensin inhibitors. As a result, the median kidney survival period of patients in this cohort was found to be at 35 years with a strong genotype-phenotype correlation. The median age at the onset of end stage kidney disease (ESKD) significantly differed between patients treated with and without renin-angiotensin inhibitors (over 50 years versus 28 years, respectively). Moreover, these drugs delayed the onset of ESKD in patients with truncating variants for 12 years, extending the median age from 16 years to 28 years. Thus, our results confirmed a strong genotype-phenotype correlation in patients with male X-linked Alport syndrome. Additionally, it was suggested that renin-angiotensin inhibitors could significantly delay ESKD progression. Despite these therapies, patients with truncating variants developed ESKD at the median age of 28 years.