Congenital Nephrotic Syndrome Research Articles

The clinical characteristics and genotype analysis of LAMB2 gene mutation.

To report a case of steroid-resistant nephrotic syndrome caused by a LAMB2 gene mutation, examine the associated literature, outline the clinical and genetic features of Pierson syndrome, and deepen the clinical comprehension of this condition. The study involved retrospective summary and analysis of the clinical presentations, genetic mutation features, and prognosis of one case involving a LAMB2 gene mutation. PubMed, Medline, Web of Science, CNKI, and Wanfang databases were searched to gather and summarize information on the pathological phenotypes and genotypic alterations associated with LAMB2 mutations. A 9-month-old infant presented with edema and massive proteinuria, along with horizontal nystagmus and miosis, manifesting clinically as steroid-resistant nephrotic syndrome. Ocular symptoms prompted both a kidney biopsy and genetic testing. The biopsy revealed minimal change disease, while genetic testing identified compound heterozygous mutations in the LAMB2 gene: c.1405C > T (p.R469X) and c.1066 T > A (p.C356S), inherited from the father and mother, respectively. These mutations were determined to be novel. The diagnosis was confirmed as a LAMB2 gene mutation. A literature review of 26 cases with LAMB2 mutations indicated these typically presented as steroid-resistant or congenital nephrotic syndrome, with 14 cases also displaying ocular symptoms. Among the 18 cases undergoing kidney biopsy, findings included focal segmental glomerulosclerosis in 10 cases, minimal change disease in 4 cases, diffuse mesangial sclerosis in 2 cases, IgM nephropathy in 1 case, and mesangial proliferation in 1 case. Electron microscopy in 10 cases showed basement membrane splitting. Genetic analysis revealed 15 cases with compound heterozygous mutations, 5 with homozygous mutations, 3 with heterozygous mutations, 2 with frame-shift mutations, and 1 with a truncating mutation. 16 out of the 26 reported cases progressed to end-stage kidney disease. Mutations in the LAMB2 gene primarily manifest as steroid-resistant or congenital nephrotic syndrome, often accompanied by ocular abnormalities, suggesting a strong likelihood of this disease. The results of genetic testing offer a foundational basis for clinical diagnosis. The identification of a new mutation site in this case expands the known spectrum of mutations in the LAMB2 gene. Unfortunately, the prognosis associated with this condition is generally poor.

Clinical and Genetic Differences between Congenital and Infantile Nephrotic Syndrome

Clinical and Genetic Differences between Congenital and Infantile Nephrotic Syndrome

Adeno-Associated Virus (AAV)-Mediated Gene Therapy in Nphs1 Knockout Mice: A Strategy for Treating Congenital Nephrotic Syndrome

Adeno-Associated Virus (AAV)-Mediated Gene Therapy in Nphs1 Knockout Mice: A Strategy for Treating Congenital Nephrotic Syndrome

Genotype-Phenotype Correlations in Congenital Nephrotic Syndrome Associated with Nephrin Gene C-terminal Mutations

Genotype-Phenotype Correlations in Congenital Nephrotic Syndrome Associated with Nephrin Gene C-terminal Mutations

Консервативная тактика ведения врожденного и инфантильного нефротического синдрома: опыт одного центра

Treatment tactics for patients with congenital nephrotic syndrome (CNS) varies from aggressive kinds, such as early nephrectomy, to conservative ones that include diuretic and nutritional support. The purpose of this research was to assess the effectiveness of conservative treatment of children with congenital and infantile nephrotic syndromes. Materials and methods used: a single-center retrospective study of 11 pediatric patients who had been manifested with NS within their first year of life and had required diuretic therapy, was conducted. The effectiveness of conservative therapy was assessed as preservation of the renal function according to glomerular filtration and satisfactory weight/height and height alone parameters’ dynamics that ensure the safety of kidney transplantation. Results: despite the molecular genetic study was conducted in all 250 children with NS, the described 11 have had verified pathogenic variants as follows: in the NPHS1 gene in 5 (45.5%, CI 16.8-76.6%), in the NPHS2 gene in another 5 (45.5%, CI 16.8-76.6%) and a single patient with none of a kind. It was revealed that despite the persistence of pronounced NS laboratory activity, the edema gradually disappeared against the background of conservative therapy, which in its turn had made it possible to refrain from early nephrectomy as well as to begin the renal replacement therapy over the age of 3 (4) y/o. 9 (81.8%, CI 48.2-97.7%) had satisfactory weight and height parameters at the age of 3 y/o. Only a single patient had undergone the early nephrectomy at the age of 4 months old, that was then followed by a successful kidney transplant at the age of 1 year and 4 months old, which, however, did not affect the then positive height prognosis. Conclusion: thus, reasonably selected conservative therapy for CNS can be effective against edematous syndrome and contribute to satisfactory weight/height growth parameters without early nephrectomy and, accordingly, the start of dialysis during the first year of life.

Clinical presentations and outcomes of congenital and infantile nephrotic syndrome.

Objective: To describe the characteristics and outcomes of congenital nephrotic syndrome (CNS) and infantile nephrotic syndrome (INS). Study Design: Cross-sectional study. Setting: Department of Pediatric Nephrology, National Institute of Child Health, Karachi, Pakistan. Period: July 2023 to January 2024. Methods: All cases of CNS or INS visiting the outpatient, emergency department, or admitted in Nephrology ward were analyzed. Data including demographic characteristic and anthropometric measurements, clinical history and presentation were noted. Short-term outcomes in terms of cases who were discharged from hospital or those who died were recorded. Results: In a total of 33 infants, 17 (51.5%) were male. The mean age was 5.8±3.2 months. The mean days from onset of edema to the time of enrollment was 33.27±22.63 days. The most common presenting features were ascites noted in 4 (12.1%). Associated infections were reported in 21 (63.6%) infants. INS and CNS were noted in 25 (75.8%) and 8 (24.2%) infants respectively. Mortality was reported in 11 (33.3%) infants. Conclusion: Infections were the most common associated conditions in congenital and infantile nephrotic syndrome. Short term outcomes exhibiting high mortality rates warrants early identification and treatment of congenital and infantile nephrotic syndrome.

Phenotypic quantification of Nphs1-deficient mice.

Steroid-resistant nephrotic syndrome (SRNS) is the second most frequent cause of chronic kidney disease in children and young adults. The most severe form of steroid-resistant nephrotic syndrome is congenital nephrotic syndrome Finnish type (CNSF), caused by biallelic loss-of-function variants inNPHS1,encoding nephrin. Since each of the 68 monogenic causes of steroid-resistant nephrotic syndrome represents a rare cause of the disease, tailoring therapeutic interventions to multiple molecular targets remains challenging, suggesting gene replacement therapy (GRT) as a viable alternative. To set the ground for a gene replacement study in vivo, we established rigorous, quantifiable, and reproducible phenotypic assessment of a conditional Nphs1 knockout mouse model. By breeding a floxed Nphs1fl/- mouse (Nphs1tm1Afrn/J) previously studied for pancreatic β-cell survival with a podocin promoter-driven Cre recombinase mouse model (Tg(NPHS2-Cre)295Lbh/J), we generated mice with podocyte-specific nephrin deficiency (Nphs1fl/fl NPHS2-Cre +). We observed a median survival to postnatal day P5 in nephrin-deficient mice, whereas heterozygous control mice and wild type (WT) control group showed 90% and 100% survival, respectively (at P50 days). Light microscopy analysis showed a significantly higher number of renal-tubular microcysts per kidney section in nephrin-deficient mice compared to the control groups (P < 0.0022). Transmission electron microscopy demonstrated reduced foot process (FP) density in nephrin-deficient mice compared to controls (P < 0.0001). Additionally, proteinuria quantitation using urine albumin-to-creatinine ratio (UACR) was significantly higher in nephrin-deficient mice compared to controls. This study represents the first comprehensive description of the kidney phenotype in anephrin-deficient mouse model, laying the foundation for future gene replacement therapy endeavors.

Quantifiable and reproducible phenotypic assessment of a constitutive knockout mouse model for congenital nephrotic syndrome of the Finnish type

Steroid-resistant nephrotic syndrome (SRNS) is the second most frequent cause of childhood chronic kidney disease. Congenital nephrotic syndrome of the Finnish type (CNF) (MIM# 256300) is caused by biallelic variants in the gene NPHS1, encoding nephrin, an integral component of the kidney filtration barrier. No causal treatments exist, and children inevitably require kidney replacement therapy. In preparation for gene replacement therapy (GRT) in CNF, we established a quantifiable and reproducible phenotypic assessment of the nephrin-deficient CNF mouse model: 129/Sv-Nphs1tm1Rkl/J. We assessed the phenotypic spectrum of homozygous mice (Nphs1tm1Rkl/Nphs1tm1Rkl) compared to heterozygous controls (Nphs1tm1Rkl/Nphs1WT) by the following parameters: 1. cohort survival, 2. podocyte foot process (FP) density per glomerular basement membrane (GBM) using transmission electron microscopy, 3. tubular microcysts in brightfield microscopy, and 4. urinary albumin/creatinine ratios. Nphs1tm1Rkl/Nphs1tm1Rkl mice exhibited: 1. perinatal lethality with median survival of 1 day, 2. FP effacement with median FP density of 1.00 FP/µm GBM (2.12 FP/µm in controls), 3. tubular dilation with 65 microcysts per section (6.5 in controls), and 4. increased albumin/creatinine ratio of 238 g/g (4.1 g/g in controls). We here established four quantifiable phenotyping features of a CNF mouse model to facilitate future GRT studies by enabling sensitive detection of phenotypic improvements.

Long-term graft survival in a kidney transplant recipient with glioblastoma: Case report

Long-term immunosuppression after transplantation can increase the risk of cancer development in recipient patients. This case report describes the treatment approach for glioblastoma in a kidney transplant recipient after transplantation. The patient, a 61-year-old woman, received a living donor kidney transplant 24 years ago due to congenital nephrotic syndrome. The patient was on various immunosuppressive medications, including cyclosporine, prednisolone, and mycophenolate mofetil.After 16 years of follow-up, the patient presented with symptoms of brain tumor, leading to further tests. Subsequent examination revealed the presence of a tumor that had spread to frontal region within the brain.A surgical procedure was subsequently conducted to extract the tumor cells and alleviate the resulting pressure within the brain. Based on pathology results, it was determined that the patient had glioblastoma.Methylation of the O6-methylguanine-DNA methyltransferase (MGMT) promoter was detected, indicating the potential response to chemotherapy. Chemotherapy was initiated, along with radiation therapy.After the diagnosis and surgery, the patient's medications for the kidney transplant were modified. Rapamycin replaced the previous medications, and the dose of mycophenolate mofetil and prednisolone was decreased. After 7 years, the patient's kidney is functioning well, with a creatinine level of 1.5, and brain imaging showed no abnormalities. After kidney transplantation, there is an increased risk of various cancers.Overall, this case report demonstrates a successful treatment approach for glioblastoma after kidney transplantation, emphasizing the need for close monitoring and individualized management in transplant recipients at risk for cancer development.Considering the current stability of the patient's condition after a change in medication regimen, patients who have been using the drug Cyclosporine for a long time should be included in future evaluations due to its carcinogenic properties.

Rivaroxaban for the Treatment of Venous Thromboembolism in NPHS1 Congenital Nephrotic Syndrome

Rivaroxaban for the Treatment of Venous Thromboembolism in NPHS1 Congenital Nephrotic Syndrome

Late nephrectomy in infants with congenital nephrotic syndrome of the Finnish type.

Bilateral nephrectomy is commonly performed in patients with congenital nephrotic syndrome of the Finnish type. The optimal timing of nephrectomy is unclear. Growth, thromboembolic events, infections, transplant-related complications and ability to eat were compared between infants with early (Group 1, n = 13) and late (Group 2, n = 10) nephrectomy. 'Early' was defined as nephrectomy at 7-kg body weight followed by peritoneal dialysis and 'late' as nephrectomy at ≥10 kg followed by 3-4 weeks of haemodialysis and kidney transplantation. Patients were followed until the end of the first post-transplant year. Dialysis time was significantly longer in group 1 than in group 2. Late nephrectomy did not increase the risk for thromboembolic events or septicaemia but decreased tube feeding dependency (group 1 69% vs. group 2 20%, p = 0.019). Motor development at transplantation was considered normal in 80% of the infants with late nephrectomy compared to 31% in the early nephrectomy group (p = 0.019); however, the difference between the groups disappeared by the end of the follow-up. Infants with late nephrectomy have comparative outcome but less feeding tube dependency and better motor development during the first post-transplant months compared to infants with early nephrectomy.

#901 Natural history of idiopathic nephrotic syndrome: the UK National RaDaR Idiopathic Nephrotic Syndrome Cohort

Abstract Background and Aims Idiopathic nephrotic syndrome (INS) is an important class of proteinuric renal disease leading to kidney failure (KF). Here we describe the natural history of INS and congenital nephrotic syndrome (NS) using the UK National Registry of Rare Kidney Diseases Idiopathic Nephrotic Syndrome (RaDaR-INS) Cohort, including retrospective and prospective data from 4610 patients with NS not attributable to glomerulonephritis or systemic disorders recruited from 107 adult and paediatric kidney units across the UK since 2010. Method Participant eligibility of RaDaR-INS Cohort patients included ≥12 months observation from disease onset and no KF (CKD stage 5 or on renal replacement therapy) at or prior to disease onset. Disease onset date was defined as first database occurrence of kidney biopsy, primary diagnosis or protein-creatinine ratio (PCR) ≥1.5 g/g. Participants were sub-categorized into those with a genetic diagnosis (INS-genetic), biopsy-proven FSGS (FSGS-biopsy), biopsy–proven minimal change disease (MCD-biopsy) and those with no genetic or biopsy-proven diagnosis (INS-no genetic or biopsy diagnosis). Participants with a biopsy-proven MCD diagnosis and a subsequent biopsy proven FSGS diagnosis were included in both MCD-biopsy and FSGS-biopsy categories and formed a category of their own (MCD progressing to FSGS). Longitudinal proteinuria, assessed as time-average protein-to-creatinine ratio (TA-PCR), and eGFR slope were calculated over the full duration of follow-up or until KF. Kidney survival was calculated from disease onset to event (KF or death) and censored at last follow-up. Results Of the 4066 patients meeting eligibility, median age at disease onset was 28 years (IQR 6-51), with children (&amp;lt;18 yrs) representing 39% of the study population. Median proteinuria was 6.4 g/g (IQR 3.1-10.8; n = 923), while mean eGFR was 118 mL/min/1.73 m2 (SD 49; n = 240) and 69 mL/min/1.73 m2 (SD 34; n = 906) for children and adults, respectively. Median follow-up duration was 8.2 yrs (IQR 4.3-13.1) with KF/death events occurring in 30% of patients. Mean TA-PCR was greater in children than adults (5.0 g/g (SD 13.9) vs. 1.9 g/g (SD 2.5), as was annual rate of loss of eGFR (−7.4 mL/min/1.73 m2 (SD 21.8) vs. −3.1 mL/min/1.73 m2 (SD 10.2)). Characteristics at disease onset and clinical outcomes of the INS cohort sub-categories are presented in Fig. 1. Kaplan Meier survival plots of each sub-category, and further divided into children and adults, illustrate the poor survival probability for patients with FSGS, particularly INS-genetic patients who are predominantly diagnosed in childhood (Fig. 2). While INS with no genetic or biopsy diagnosis presenting in childhood exhibits disease course and outcomes similar to MCD-biopsy patients, those diagnosed in adulthood have a more rapid disease course similar to FSGS-biopsy patients. Conclusion The RaDaR-INS cohort represents a large study population with lengthy follow-up data. These analyses illustrate the difference in disease progression and survival rates for INS patients with different causes or histological descriptions, highlighting in particular an unmet need for effective treatments for patients with nephrotic syndrome and FSGS.

Serological responses to immunization during nephrosis in infants with congenital nephrotic syndrome of the Finnish type.

Pretransplant vaccination is generally recommended to solid organ transplant recipients. In infants with congenital nephrotic syndrome (CNS), the immune response is hypothetically inferior to other patients due to young age and urinary loss of immunoglobulins, but data on the immunization response in severely nephrotic children remain scarce. If effective, however, early immunization of infants with CNS would clinically be advantageous. We investigated serological vaccine responses in seven children with CNS who were immunized during nephrosis. Antibody responses to measles-mumps-rubella -vaccine (MMR), a pentavalent DTaP-IPV-Hib -vaccine (diphtheria, tetanus, acellular pertussis, inactivated poliovirus, Haemophilus influenzae type b), varicella vaccine, combined hepatitis A and B vaccine, and pneumococcal conjugate vaccine (PCV) were measured after nephrectomy either before or after kidney transplantation. Immunizations were started at a median age of 7 months [interquartile range (IQR) 7-8], with a concurrent median proteinuria of 36,500 mg/L (IQR 30,900-64,250). Bilateral nephrectomy was performed at a median age of 20 months (IQR 14-25), and kidney transplantation 10-88 days after the nephrectomy. Antibody levels were measured at median 18 months (IQR 6-23) after immunization. Protective antibody levels were detected in all examined children for hepatitis B (5/5), Clostridium tetani (7/7), rubella virus (2/2), and mumps virus (1/1); in 5/6 children for varicella; in 4/6 for poliovirus and vaccine-type pneumococcal serotypes; in 4/7 for Haemophilus influenzae type B and Corynebacterium diphtheriae; in 1/2 for measles virus; and in 2/5 for hepatitis A. None of the seven children had protective IgG levels against Bordetella pertussis. Immunization during severe congenital proteinuria resulted in variable serological responses, with both vaccine- and patient-related differences. Nephrosis appears not to be a barrier to successful immunization.

Early diagnosis and management of finish type congenital nephrotic syndrome in a 3-year-old child: A case report

This study describes a 3-year-old non Finnish girl who was diagnosed with Finnish-type nephrotic syndrome (FTNS), a rare kidney illness brought on by NPHS1 gene abnormalities. Even though she had low protein levels and severe swelling when she was three months old, her case of congenital nephrotic syndrome (CNS) was incorrectly identified as minimal change disease (MCD). The standard MCD treatments, cyclosporine and steroids, did not affect her. A genetic test and a kidney sample confirmed the diagnosis of FTNS, a condition that necessitates an early renal transplant for survival. She is awaiting a kidney transplant and was treated with drugs that save proteins to lessen her edema. The study emphasizes the significance of FTNS early and correct diagnosis as well as the requirement for alternate treatments for this difficult illness.

Impact of childhood nephrotic syndrome on obesity and growth: a prospective cohort study.

Children with nephrotic syndrome are at risk of obesity and growth impairment from repeated steroid treatment. However, incidence and risk factors for obesity and short stature remain uncertain, which is a barrier to preventative care. Our aim was to determine risk, timing, and predictors of obesity and short stature among children with nephrotic syndrome. We evaluated obesity and longitudinal growth among children (1-18years) enrolled in Insight into Nephrotic Syndrome: Investigating Genes, Health, and Therapeutics. We included children with nephrotic syndrome diagnosed between 1996-2019 from the Greater Toronto Area, Canada, excluding congenital or secondary nephrotic syndrome. Primary outcomes were obesity (body mass index Z-score ≥ + 2) and short stature (height Z-score ≤ -2). We evaluated prevalence of obesity and short stature at enrolment (< 1-year from diagnosis) and incidence during follow-up. Cox proportional hazards models determined the association between nephrotic syndrome classification and new-onset obesity and short stature. We included 531 children with nephrotic syndrome (30% frequently relapsing by 1-year). At enrolment, obesity prevalence was 23.5%, 51.8% were overweight, and 4.9% had short stature. Cumulative incidence of new-onset obesity and short stature over median 4.1-year follow-up was 17.7% and 3.3% respectively. Children with frequently relapsing or steroid dependent nephrotic syndrome within 1-year of diagnosis were at increased risk of new-onset short stature (unadjusted hazard ratio 3.99, 95%CI 1.26-12.62) but not obesity (adjusted hazard ratio 1.56, 95%CI 0.95-2.56). Children with ≥ 7 and ≥ 15 total relapses were more likely to develop obesity and short stature, respectively. Obesity is common among children with nephrotic syndrome early after diagnosis. Although short stature was uncommon overall, children with frequently relapsing or steroid dependent disease are at increased risk of developing short stature. Effective relapse prevention may reduce steroid toxicity and the risk of developing obesity or short stature.

Quantitative phenotyping of Nphs1 knockout mice as a prerequisite for gene replacement studies.

Steroid-resistant nephrotic syndrome (SRNS) is the second most frequent cause of chronic kidney disease before the age of 25 yr. Nephrin, encoded by NPHS1, localizes to the slit diaphragm of glomerular podocytes and is the predominant structural component of the glomerular filtration barrier. Biallelic variants in NPHS1 can cause congenital nephrotic syndrome of the Finnish type, for which, to date, no causative therapy is available. Recently, adeno-associated virus (AAV) vectors targeting the glomerular podocyte have been assessed as a means for gene replacement therapy. Here, we established quantitative and reproducible phenotyping of a published, conditional Nphs1 knockout mouse model (Nphs1tm1.1Pgarg/J and Nphs2-Cre+) in preparation for a gene replacement study using AAV vectors. Nphs1 knockout mice (Nphs1fl/fl Nphs2-Cre+) exhibited 1) a median survival rate of 18 days (range: from 9 to 43 days; males: 16.5 days and females: 20 days); 2) an average foot process (FP) density of 1.0 FP/µm compared with 2.0 FP/µm in controls and a mean filtration slit density of 2.64 µm/µm2 compared with 4.36 µm/µm2 in controls; 3) a high number of proximal tubular microcysts; 4) the development of proteinuria within the first week of life as evidenced by urine albumin-to-creatinine ratios; and 5) significantly reduced levels of serum albumin and elevated blood urea nitrogen and creatinine levels. For none of these phenotypes, significant differences between sexes in Nphs1 knockout mice were observed. We quantitatively characterized five different phenotypic features of congenital nephrotic syndrome in Nphs1fl/fl Nphs2-Cre+ mice. Our results will facilitate future gene replacement therapy projects by allowing for sensitive detection of even subtle molecular effects.NEW & NOTEWORTHY To evaluate potential, even subtle molecular, therapeutic effects of gene replacement therapy (GRT) in a mouse model, prior rigorous quantifiable and reproducible disease phenotyping is necessary. Here, we, therefore, describe such a phenotyping effort in nephrin (Nphs1) knockout mice to establish the basis for GRT for congenital nephrotic syndrome. We believe that our findings set an important basis for upcoming/ongoing gene therapy approaches in the field of nephrology, especially for monogenic nephrotic syndrome.

Congenital Nephrotic Syndrome: A Case Report

Congenital nephrotic syndrome (CNS) is a rare disorder characterized by massive proteinuria, hypoalbuminemia, hyperlipidemia, and edema that occurs in the first three months of life. The incidence of CNS is about 1.5% of all cases of nephrotic syndrome in children, while the incidence in children is about 2 per 100,000. The pathogenesis of CNS is thought to be due to genetic defects in the components of the glomerular filtration barrier, particularly nephrin and podocin, which cause most similar cases. A perinatal infection may also cause CNS. The most common type of primary CNS is the Finnish type, inherited in an autosomal recessive manner. We report a case of a six-month-old male patient who presented with swelling of the face, abdomen, and genitals since the age of 3 months, which had worsened a week before admission to the hospital. There was no history of nausea, vomiting, fever, or seizures, and the child could drink milk. Physical examination revealed ascites with positive shifting dullness and pretibial, dorsum pedis, and scrotum edema. The liver and spleen were difficult to assess. Laboratory examination revealed leukocytosis (27.8x103/µL), anemia (7.7 g/dL), thrombocytosis (537x103/μL), hypoalbuminemia (1.5 g/dL), dyslipidemia (total cholesterol 374 mg/dL, HDL 7 mg/dL, LDL 69 mg/dL, triglycerides 1196 mg/dL), proteinuria (+3/300), and hematuria (+3/200). A history of urological ultrasound showed right and left nephropathy with mild hydronephrosis and ascites. To sum up, we reported male patient 6 months with congenital nephrotic syndrome. Chromosomal analysis is recommended in this case.

New insights from the genetic work-up in early onset nephrotic syndrome: report from a registry in western India.

Eighty-five percent of infants with congenital nephrotic syndrome (CNS) and 66% with infantile NS (INS) are likely to have a monogenic etiology. There exists a significant genetic variability between different regions and ethnic groups. This study aimed to determine the genetic defects in children with CNS and INS by establishing a registry in western India. In this cross-sectional study, pediatric nephrologists from 13 private and government institutions shared relevant clinical data and details of the genetic evaluation of children presenting with NS within the first year of life. The median age at presentation was 9months (range 1-23, IQR 3-13months), history of consanguinity between parents existed in 14 patients (34%), family history of similar illness in 6 (15%), and extra-renal manifestations in 17 (41%). Twenty-five (61%) were confirmed to have a monogenic etiology. NPHS1 gene was the most implicated (9/25) followed by PLCE1 (5/25). There were 12 variants of uncertain significance (VUS) involving 10 genes (10/25, 40%), and no definite genetic abnormality was found in 4 (25%). A re-analysis of these VUS attempted 2-3years later facilitated reclassification of 7/12 (58%); increasing the diagnostic yield from 61 to 68.2%. Consistent with worldwide data, variants in NPHS1 gene were the most common cause of NS in infancy; however, PLCE1 was implicated more frequently in our cohort. NUP93 and COL4A3 were reported in early onset NS for the first time. Reclassification of VUS should be attempted, if feasible, since it may lead to a useful revision of diagnosis.

Genotype/phenotype relationship in mild congenital nephrotic syndrome

Introduction. Congenital nephrotic syndrome (CNS) is a severe disease complicated by hemodynamic instability, infections, thrombosis, growth disorder and progressive renal failure leading to end-stage kidney disease within a few years. The mutations of NPHS1 encoding nephrin is the most common cause of the CNS. The aim of this paper was to present a patient with NPHS1 homozygous Ser350Pro missense mutation that unexpectedly caused a mild clinical course of CNS. Case outline. We present a female patient who was diagnosed with severe nephrotic syndrome at 2.5 months of age. While waiting for the result of the genetic analysis, she was treated unsuccessfully with corticosteroids and angiotensin converting inhibitor (ACEI) four weeks, and then under Cyclosporine A (CsA) and ACEI she achieved partial remission within three months. Initially, the milder clinical course was explained by the positive effect of CsA, but as partial remission persisted even after the discontinuation of this drug, it remains unclear what influenced the improvement of the clinical course of the disease. At the time of writing this paper, the patient was 10.9 years old with normal serum creatinine, normal blood pressure and non-nephrotic proteinuria. Conclusion. NPHS1 homozygous Ser350Pro missense mutation may be presented by a mild clinical course of CNS. Further studies are needed to clarify a more predictive CNS genotype/phenotype relationship.

Factors associated with early relapses in children with steroid-sensitive nephrotic syndrome.

Objective: To determine different risk factors associated with relapse in children with steroid-sensitive nephrotic syndrome. Study Design: Cross-sectional study. Setting: Department of Pediatric Nephrology, The National Institute of Child Health, Karachi. Period: April 2021 to October 2022. Material &amp; Methods: With a sample size of 170 Children aged 1-12 years of either gender were included in the study by non-probability consecutive sampling. Patients who had congenital nephrotic syndrome previously received immunosuppressive treatment or had any other systemic disease leading to nephrotic syndrome were excluded from the study. Frequencies and percentages were calculated for the quantitative variables while chi-square test was applied for the qualitative variables-value of &lt;0.05 was considered significant. Results: The mean age of the patients was 4.87±2.54 years. The majority of the frequent relapsers (76) were male. The mean serum cholesterol of the patients was 318.71±61.61mg/dl. Of the total sample, 37 (21.76%) were infrequent relapsers and 133 (78.23 %) were frequent relapsers. A significant association was found between upper respiratory tract infection and frequent relapse with a p-value of 0.038. Conclusion: Our study showed a significant association between upper respiratory tract infection and relapse in children with steroid-sensitive nephrotic syndrome.