Clinicopathological features and outcome of secondary steroid resistant nephrotic syndrome: A retrospective analysis.

Objective: To determine the clinico-pathological features and long-term outcome of secondary steroid-resistant nephrotic syndrome treated with steroids and calcineurin inhibitors. METHODS: The retrospective cohort study was conducted at the Sindh Institute of Urology and Transplant, Karachi, in June and July 2023, and comprised data from January 1, 2008, to December 31, 2020, of children aged 1-18 years who developed steroid resistance after initial sensitivity to steroids with at least 1-year of follow-up. Demographics as well as time taken to secondary steroid response were documented. Renal biopsy of all patients with secondary steroid resistance had been performed. Eventual outcomes after treatment with calcineurin inhibitors based on the degree of proteinuria and serum albumin levels were used to categorise complete remission, partial remission and no response. Kidney function, as determined by estimated glomerular filtration rate, was recorded. Data was analysed using SPSS 22. RESULTS: Of the 1,000 patients who underwent renal biopsy for steroid resistance, 48(4.8%) had idiopathic steroid-resistant nephrotic syndrome; 32(66.7%) males, 16(33.3%) females and median age of 5 years (interquartile range: 4-7.3 years). Median age at diagnosis of nephrotic syndrome was 5 years (interquartile range: 3.6-7.3 years). The median time from nephrotic syndrome to secondary steroid-resistant nephrotic syndrome was 23 months (interquartile range: 8.75-44.5 months). Biopsy results at diagnosis showed that 27(56.3%) had minimal change disease. The mean follow-up time was 6.1±3.2 years. Of the 43(89.5%) patients who received cyclosporin for 1 year, 29(67%) obtained complete remission, 5(12%) attained partial remission and no response was seen in 9(21%) patients. Conclusion: Majority of the children had minimal change disease at the time of diagnosis of secondary steroid-resistant nephrotic syndrome. The long-term response with calcineurin inhibitors was favourable at 1 year.

Steroid induced ocular complications in idiopathic nephrotic syndrome: a cross sectional single center study.

Objective: To screen children receiving steroids to identify ocular complications and their prevalence. METHODS: The cross-sectional study was conducted at the Paediatric Nephrology and Ophthalmology departments of the Sindh Institute of Urology and Transplantation, Karachi, from May to October 2022, and comprised patients who received at least 1500mg cumulative steroid dose for a minimum of 3 months. They were screened for steroidsensitive or steroid-resistant nephrotic syndrome. Ocular examinations, including visual acuity, intraocular pressure, slit-lamp biomicroscopy, lens examination and fundus evaluation, were performed. Data was analysed using SPSS 22. RESULTS: Of the 124 subjects with mean age 8.15±2.03 years (range: 6-12 years), 64(51.6%) were boys. Steroidsensitive nephrotic syndrome was present in 97(78%) cases. The mean cumulative steroid dose was 3999.31±1564.22mg. Overall, 36(29%) children developed ocular complications. Blood pressure, number of relapses and the duration of treatment were significantly associated (p<0.05). Conclusion: Refractive errors were the most frequent side effects/complication seen among children with nephrotic syndrome who received prolonged corticosteroids.

Anti-N-methyl-D-aspartate receptor encephalitis in adults: a systematic review and analysis.

PURPOSE: To analyze predictors of treatment outcome for anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis in adults. METHODS: We performed a comprehensive literature search of PubMed, PsycInfo, and OVID. We included 424 patients from case reports and case series. Demographics, anti-NMDAR antibodies, prodromal and presenting symptoms, diagnostic workup, and treatment variables were recorded. Inferential analyses were performed in the subset (n = 299) of those with known treatment outcomes. Multivariate multinomial logistic regression analysis for treatment outcome compared full recovery versus partial recovery and full recovery versus death. RESULTS: Treatment outcomes consisted of 34.67% full recovery (n = 147), 30.90% partial recovery (n = 131), 4.95% death (n = 21), and 29.48% unknown (n = 125). Speech/language abnormality and abnormal electroencephalogram (EEG) were each significantly associated with a higher relative risk for a full recovery. Treatment with intravenous immunoglobulin and plasmapheresis were each significantly associated with a higher relative risk for partial recovery. The analysis comparing death to full recovery found that catatonia was significantly associated with a lower relative risk for death. Increased age, orofacial dyskinesia, and no tumor removal were each significantly associated with a higher relative risk for death. CONCLUSION: Increased age, orofacial dyskinesia, and no tumor removal were associated with a higher relative risk for death in anti-NMDAR encephalitis in adults. Clinicians should monitor and appropriately treat anti-NMDAR encephalitis with these findings to minimize the risk of death.

Primary hyperoxaluria: Comprehensive mutation screening of the disease causing genes and spectrum of disease-associated pathogenic variants.

The primary hyperoxalurias are rare disorders of glyoxylate metabolism. Accurate diagnosis is essential for therapeutic and management strategies. We conducted a molecular study on patients suffering from recurrent calcium-oxalate stones and nephrocalcinosis and screened primary hyperoxaluria causing genes in a large cohort of early-onset cases. Disease-associated pathogenic-variants were defined as missense, nonsense, frameshift-indels, and splice-site variants with a reported minor allele frequency <1% in controls. We found pathogenic-variants in 34% of the cases. Variants in the AGXT gene causing PH-I were identified in 81% of the mutation positive cases. PH-II-associated variants in the GRHPR gene are found in 15% of the pediatric PH-positive population. Only 3% of the PH-positive cases have pathogenic-variants in the HOGA1 gene, responsible to cause PH-III. A population-specific AGXT gene variant c.1049G>A; p.Gly350Asp accounts for 22% of the PH-I-positive patients. Pathogenicity of the identified variants was evaluated by in-silico tools and ACMG guidelines. We have devised a rapid and low-cost approach for the screening of PH by using targeted-NGS highlighting the importance of an accurate and cost-effective screening platform. This is the largest study in Pakistani pediatric patients from South-Asian region that also expands the mutation spectrum of the three known genes.

Proteinuria in Asymptomatic Siblings of Children with Steroid Resistant Nephrotic Syndrome: A Screening Using Urinary Dipstick.

OBJECTIVE: To screen asymptomatic siblings of steroid-resistant nephrotic syndrome patients for proteinuria using the urinary dipstick method to determine the involvement of siblings in the familial and likely genetic cause of the steroid-resistant nephrotic syndrome. METHODS: This cross-sectional study was performed at the outpatient department of Sindh Institute of Urology and Transplantation (SIUT) from May to July 2021. RESULTS: Out of 104 patients with steroid-resistant nephrotic syndrome, siblings of 66 patients were enrolled. Mean age of primary patients with steroid resistant nephrotic syndrome was 8.7±4.3 years. Most common histopathological diagnosis was focal segmental glomerulosclerosis in 25 (37.9%) children followed by minimal change disease in 17(25.8%) of them. The majority, 48 (72.7%) patients were on immunosuppressive treatment, while 4 (6.1%) had progressed to chronic kidney disease (CKD). A total of 178 siblings were recruited in the study. There were 99(55.6%) boys and 79(44.4%) girls. Their mean age was 10.67±6.2 years. Consanguinity was high in our study population i.e. 56(84%) families. Positive proteinuria on dipstick was detected in only 5(7.5%) enrolled SRNS families. One family refused further testing. Two of the five affected siblings had nephrotic range proteinuria. Renal biopsy of one of them showed membranous nephropathy while the second showed mesangiocapillary glomerulonephritis. Both had normal renal functions. CONCLUSIONS: The frequency of proteinuria in asymptomatic siblings of children with steroid-resistant syndrome is low in our population despite a high prevalence of consanguineous marriages. Hence, familial involvement of nephrotic syndrome is low and further genetic testing for monogenic causes is required in steroid-resistant nephrotic syndrome cases.

Primary hyperoxaluria and genetic linkages: an insight into the disease burden from Pakistan.

Autosomal recessive disorders are prevalent in Pakistan, a developing South Asian country where consanguineous marriages are common. This study seeks to determine the prevalence of monogenic causes in children presenting with nephrocalcinosis and nephrolithiasis at a dialysis and transplant center in Karachi, Pakistan. A retrospective analysis was conducted in children aged 1-18 years presenting with nephrocalcinosis, between 2010 and 2019. Demographic information, clinical profile, laboratory parameters and stone analysis were collected, on a pre-designed questionnaire. One hundred and twenty-six children were included, with 11 and 3 diagnosed with renal tubular acidosis and Bartter's syndrome respectively. Next-generation sequencing and Sanger sequencing was performed on 112 children. Eighty-seven patients were diagnosed with primary hyperoxaluria, with mutations in alanine-glyoxylate-aminotransferase gene found in 73, followed by glyoxylate reductase/hydroxy-pyruvate reductase in 13, and 4-hydroxy-2-oxaloglutarate aldolase in 1. Twenty-five patients reported negative for mutations. Sixty-four percent were males, with a statistically significant difference (p < 0.05). History of parental consanguineous marriage was found in 98% of the cohort. Fifty-four and 40 patients presented to the clinic with Chronic Kidney Disease Stage 1 and Stage 5, respectively, with a statistically significant difference p = 0.007. Mutations noted in our cohort are different and more severe than those reported in the developed world. The disease poses a major disease burden in developing world context with the only treatment option of combined liver-kidney transplantation not available in Pakistan.

Acquired Cystic Kidney Disease: A Hidden Complication in Children on Chronic Hemodialysis.

Objective To determine the frequency of acquired cystic kidney disease (ACKD) in children on chronic hemodialysis. Material and methods In this single-center cross-sectional study, 150 children were included who were on chronic hemodialysis for six months. Ultrasound was done to see the renal cysts. Cystic changes that could not fulfill the criteria for ACKD were also noted and analyzed. Results The mean age was 14.5 ± 3.5 years, of these 63 (42%) were males. Acquired cysts were detected in 53 (35%) of the patient and 18 patients (12%) had solitary cysts. The distribution of these entities was similar across all age groups. The underlying etiologies in the descending order were unknown 64 (43%), stone disease 31 (21%), each of the congenital anomalies of the kidney and urinary tract, and glomerulonephritis 23 (15%), and others nine (6%). A higher frequency of ACKD was detected in the children on renal replacement therapy for more than two years (33 out of 53 children, 63% with a p-value of 0.004). Conclusion The ACKD was found in one-third of our hemodialysis children and its frequency increases with the duration of hemodialysis. This percentage may not reflect the true prevalence as there is a lack of consensus on the definition of ACKD. Periodic assessment of chronic kidney disease patients for the development of ACKD especially on chronic hemodialysis is required to reduce the morbidity.

Factors Predicting Short Term Outcome in Children With Idiopathic Nephrotic Syndrome: A Prospective Cohort Study.

Objective The objective of the article is to determine the risk factors associated with relapses in children with idiopathic nephrotic syndrome (INS). Material and methods Fifty-seven children with the first episode of INS were included and followed up prospectively for a minimum period of one year to identify the risk factors related to relapses. The study subjects were divided into early (less than eight days) and late (equal to or more than eight days) responder groups and were compared in terms of the number of days to achieve complete remission, time to first relapse, and the pattern of relapse at the last follow-up. Results Of the 57 children, 32 (56%) were male and 25 (44%) female. The mean age of the study cohort was 5.3 ± 3 years. Sixteen (55%) children with ages ranging from one to four years had a higher propensity to develop relapse, although the p-value (p=0.11) was not significant. Gender analysis did not reveal any significant correlation (p=0.32); however, a higher proportion of males (n=17; 63%) responded within eight days of starting steroids than female counterparts (n=10; 37%). Microscopic hematuria at the disease onset was seen in 12 (21%) children, and out of them, five (41.6%) remained in complete remission. The mean time to achieve complete remission was 8.1 ± 3.5 days, while the early responder group had delayed time to first relapse as compared to the late responders (3.1 ± 5.2 vs. 1.6± 3.8; p=0.21). Among all the study participants, a significant number of children (n=20; 51%) were in complete remission at their last follow-up visit. Baseline serum albumin, cholesterol, body mass index (BMI), and serum creatinine had no significant difference. Conclusion The delayed response to steroids and younger age at presentation can predict the time to first relapse and number of relapses in children with INS, respectively.

Anti-NMDA Receptor Encephalitis Masquerades as Psychosis: A Case Report.

A 28-year-old male patient with an unclear history of psychosis was admitted to the inpatient psychiatric unit. He presented with auditory hallucinations, agitation, and bizarre and disorganized behavior. He was treated with antipsychotic medications without improvement. Magnetic resonance imaging of the brain showed hyperintensities throughout the brain parenchyma. Investigations for infectious, metabolic, autoimmune, and malignant etiologies were negative. Anti-N-methyl-D-aspartate (NMDA) receptor encephalitis was suspected. Cerebrospinal fluid (CSF) and serum NMDA receptor antibody testing were performed. Both tests were positive, confirming anti-NMDA receptor encephalitis. The patient was treated with intravenous immunoglobulin and methylprednisolone, which resulted in the resolution of his psychosis. In the case of unexplained psychosis associated with seizures, early screening using serum and CSF testing for anti-NMDA receptor antibodies and brain magnetic resonance imaging may be an important diagnostic tool for detecting anti-NMDA receptor encephalitis. Detailed investigations of CSF and serum should be performed to rule out infectious, metabolic, and autoimmune causes. Imaging studies should also be performed to identify any tumors such as a teratoma. This approach may help identify patients with anti-NMDA receptor encephalitis masquerading as psychosis. Early diagnosis and treatment including intravenous steroids, immunosuppressants, plasmapheresis, and removal of any teratoma if present in patients with anti-NMDA receptor encephalitis can improve the overall outcome.

Anti-N-Methyl-D-Aspartate Receptor (NMDAR) Encephalitis in Children and Adolescents: A Systematic Review and Quantitative Analysis of Reported Cases.

OBJECTIVE: This pooled analysis, from a systematic review, examines anti-N-Methyl D-Aspartate Receptor (NMDAR) encephalitis presentation in children and adolescents. METHOD: A comprehensive literature search from database inception through December 31, 2019, using PubMed, PsycInfo, and OVID was performed. Case reports and case series were included. Sample characteristics are described. Prodromal and presenting symptoms between partial recovery and full recovery are compared. The association between presenting symptoms and abnormal MRI, abnormal EEG, and tumor presence are determined. RESULTS: The sample (n=283) had a mean age of 10.8 years with 75.3% females. The most common prodromal and presenting symptom was seizure (29.7% and 63.3%, respectively). Partial and full recovery did not differ for prodromal and presenting symptoms. Multivariate logistic regression analysis found that (1) delusion were significantly associated with higher odds and aggressive behavior was associated with lower odds for abnormal findings on magnetic resonance imaging (MRI); (2) waxing and waning of symptoms were significantly associated with higher odds for abnormal electroencephalograms (EEG), and (3) increased age and psychosis were each significantly associated with increased odds, and sleep disturbance and orofacial dyskinesia with lower odds for tumor presence. CONCLUSION: Given the pattern of findings, routinely obtaining MRI and EEG should be considered for anti-NMDAR encephalitis in children and adolescents presenting with delusion and waxing and waning of symptoms, respectively. Investigation of tumors should be considered in patients with anti-NMDAR encephalitis especially when psychosis is present.

OBJECTIFS: La présente analyse combinée, tirée d'une revue systématique, examine la présentation d'une encéphalite anti-récepteur de N-méthyl-D-aspartate (NMDA) chez les enfants et les adolescents. MÉTHODE: Une recherche détaillée de la littérature à compter des débuts des bases de données jusqu'au 31 décembre 2019, dans PubMed, PsycInfo, et OVID a été menée. Les rapports de cas et les séries de cas sont inclus, et les caractéristiques de l'échantillon sont décrites. Les symptômes avant-coureurs et ceux présentés entre le rétablissement partiel et complet sont comparés. L'association entre les symptômes présentés et une IRM anormale, un EEG anormal, et la présence d'une tumeur est déterminée. RÉSULTATS: L'échantillon (n = 283) avait un âge moyen de 10,8 ans et était à 75,3 % de sexe féminin. Les symptômes avant-coureurs et présentés les plus communs étaient les convulsions (29,7 % et 63,3 %, respectivement). Le rétablissement partiel et complet ne différait pas pour les symptômes avant-coureurs et présentés. L'analyse de régression logistique multivariée a constaté que (1) le délire était significativement associé à des probabilités plus élevées, et le comportement agressif à des probabilités plus faibles de résultats anormaux à l'imagerie par résonance magnétique (IRM); (2) les variations des symptômes étaient significativement associées à des probabilités plus élevées d'électro-encéphalogrammes (EEG) anormaux; et (3) l'âge et la psychose avancés étaient chacun significativement associés à des probabilité accrues, mais le trouble du sommeil et la dyskinésie bucco-faciale étaient eux associés à des probabilités plus faibles de la présence d'une tumeur. CONCLUSION: Étant donné le modèle des résultats, obtenir automatiquement une IRM et un EEG devrait être envisagé chez les enfants et les adolescents présentant un délire et une variation des symptômes, respectivement. L'investigation de tumeurs devrait être envisagée chez les patients de l'encéphalite anti-récepteur NMDAR surtout en présence de psychose.

Prevalence of Cardiac Abnormalities in Children with Chronic Kidney Disease: A Cross-sectional Study from a Developing Country.

Improved therapeutic modalities in chronic kidney diseases (CKD) children and consequent extension of life expectancy, draws more attention towards secondary complications. Cardiovascular adaptations precipitating such terminal events, begin in pre-dialysis CKD. Hence, it's imperative to identify modifiable risk factors to direct care and resources in haltering CKD progression, evade long-term dialysis and anticipate kidney transplantation to avert cardiac complications in predialysis period. One hundred and six pre-dialysis patients aged one year to 15 years, with estimated glomerular filtration rate of <90 mL/min/1.73 m2 and proteinuria were included. Patient's history, weight, height and blood pressures (BPs) performed. Left ventricular mass index (LVMI) calculated to correct for patient height to determine raised values of >38.6 g/m2.7 and of left ventricular hypertrophy (LVH) >55 g/m2.7. Shortening fraction and ejection fraction measured to assess systolic function. Diastolic function assessed by Doppler measuring the mitral inflow (e/a) ratio. Hemoglobin, calcium phosphorous product, parathyroid hormone and hypertension measured to assess cardiac risk factor. The total prevalence of cardiac abnormality was found in 66.9% (95% confidence interval [CI] 57.6%-75.2%. Raised LVMI was seen in 64%, among which 34.9% had LVH. Diastolic and systolic dysfunction was found in 12.2% and 11.3% respectively. The cardiac abnormality was more prevalent in CKD grade IV and V. The independent risk factors were anemia and abnormal diastolic BP index which increase the risk for LVH by 3-fold and 5-fold respectively. Proportion of cardiac abnormalities were more prevalent in CKD IV and V. Anemia and diastolic hypertension were independent risk factors for LVH.

Clinicopathologic Features and the Association with Short-Term Outcome of Primary Membranous Nephropathy in Children: A Single-Center Study from Pakistan.

Membranous nephropathy (MN) is an uncommon cause of steroid-resistant nephrotic syndrome in children. Our study aimed to determine the clinicopathologic features of primary MN in children and their association with short-term outcome. This observational study was conducted from January 2009 to June 2017 at the Pediatric Nephrology Department. A total of 50 children were diagnosed with primary MN. Their clinical, laboratory, and histopathological findings on renal biopsy were recorded. The minimum follow-up was for six months. Clinicopathologic features were correlated with the outcome at the last follow-up. Data analysis was done using IBM SPSS Statistics for Windows software version 20.0. The mean age at onset was 10.92 ± 3.08 years (range: 4-17 years). The male-to-female ratio was 3:1. The serum albumin of ≤2.5 g/dL was seen in 40 patients (80%), hypertension was present in 38 (76%), and heavy proteinuria was seen in 32 children (70%). The mean estimated glomerular filtration rate (eGFR) at presentation was 178.71 ± 0.78 mL/min/1.73 m2. At the initial visit, nine children (18.4%) were in chronic kidney disease stage 2 and one (2%) in stage 4. Phospholipase A2 receptor antibody was present in five (15%) of 32 children tested. At the last follow-up (28 interquartile range: 25.5 months), 11 children (26%) were in complete remission and 25 (66%) had achieved partial remission. The mean eGFR had reduced to 145.84 ± 78.05 mL/min/1.73 m2. Patients with normal initial eGFR were more likely to go into remission (P = 0.001). The short-term outcome of childhood primary MN is relatively good in our setup. A multicenter collaborative study is required to determine prognostic factors and to standardize treatment in this uncommon nephropathy.

Whole exome sequencing identified ATP6V1C2 as a novel candidate gene for recessive distal renal tubular acidosis.

Distal renal tubular acidosis is a rare renal tubular disorder characterized by hyperchloremic metabolic acidosis and impaired urinary acidification. Mutations in three genes (ATP6V0A4, ATP6V1B1 and SLC4A1) constitute a monogenic causation in 58-70% of familial cases of distal renal tubular acidosis. Recently, mutations in FOXI1 have been identified as an additional cause. Therefore, we hypothesized that further monogenic causes of distal renal tubular acidosis remain to be discovered. Panel sequencing and/or whole exome sequencing was performed in a cohort of 17 families with 19 affected individuals with pediatric onset distal renal tubular acidosis. A causative mutation was detected in one of the three "classical" known distal renal tubular acidosis genes in 10 of 17 families. The seven unsolved families were then subjected to candidate whole exome sequencing analysis. Potential disease causing mutations in three genes were detected: ATP6V1C2, which encodes another kidney specific subunit of the V-type proton ATPase (1 family); WDR72 (2 families), previously implicated in V-ATPase trafficking in cells; and SLC4A2 (1 family), a paralog of the known distal renal tubular acidosis gene SLC4A1. Two of these mutations were assessed for deleteriousness through functional studies. Yeast growth assays for ATP6V1C2 revealed loss-of-function for the patient mutation, strongly supporting ATP6V1C2 as a novel distal renal tubular acidosis gene. Thus, we provided a molecular diagnosis in a known distal renal tubular acidosis gene in 10 of 17 families (59%) with this disease, identified mutations in ATP6V1C2 as a novel human candidate gene, and provided further evidence for phenotypic expansion in WDR72 mutations from amelogenesis imperfecta to distal renal tubular acidosis.

Mutations in multiple components of the nuclear pore complex cause nephrotic syndrome.

Steroid-resistant nephrotic syndrome (SRNS) almost invariably progresses to end-stage renal disease. Although more than 50 monogenic causes of SRNS have been described, a large proportion of SRNS remains unexplained. Recently, it was discovered that mutations of NUP93 and NUP205, encoding 2 proteins of the inner ring subunit of the nuclear pore complex (NPC), cause SRNS. Here, we describe mutations in genes encoding 4 components of the outer rings of the NPC, namely NUP107, NUP85, NUP133, and NUP160, in 13 families with SRNS. Using coimmunoprecipitation experiments, we showed that certain pathogenic alleles weakened the interaction between neighboring NPC subunits. We demonstrated that morpholino knockdown of nup107, nup85, or nup133 in Xenopus disrupted glomerulogenesis. Re-expression of WT mRNA, but not of mRNA reflecting mutations from SRNS patients, mitigated this phenotype. We furthermore found that CRISPR/Cas9 knockout of NUP107, NUP85, or NUP133 in podocytes activated Cdc42, an important effector of SRNS pathogenesis. CRISPR/Cas9 knockout of nup107 or nup85 in zebrafish caused developmental anomalies and early lethality. In contrast, an in-frame mutation of nup107 did not affect survival, thus mimicking the allelic effects seen in humans. In conclusion, we discovered here that mutations in 4 genes encoding components of the outer ring subunits of the NPC cause SRNS and thereby provide further evidence that specific hypomorphic mutations in these essential genes cause a distinct, organ-specific phenotype.

Short-term outcome of clinical and histopathologic variants of mesangiocapillary glomerulonephritis in children: A retrospective analysis from a tertiary care center.

OBJECTIVE: To study the frequency, clinicopathological features and short-term outcome of mesangiocapillary glomerulonephritis (MCGN) in children at a tertiary care kidney center in Pakistan. METHODS: A descriptive, observational study was conducted at the Paediatric Nephrology Department, Sindh Institute of Urology and Transplantation, Karachi, from January 2011 till December 2015. A review of all paediatric (<18 years) renal biopsies during the study period was performed and cases of MCGN were enrolled. The clinical presentation, laboratory findings, histology and outcome were analyzed. RESULTS: During the study period, 890 paediatric renal biopsies were performed. Of these, 63(7%) were MCGN. Among these, 34(54%) were males and 29 (46%) females. Mean age was 9.9 ± 3.2years. Thirty four (54%) presented with nephrotic syndrome (NS), and29 (46%) with rapidly progressive glomerulonephritis (RPGN).Mean duration of follow-up was 1.66 ± 1.34 years. Outcome of patients with NS with renal failure (RF)was complete remission (CR) in 1(7.7%), persistent proteinuria with normal renal functions in 1(7.7%),chronic kidney disease (CKD) in 3 (23%), end-stage renal disease (ESRD) in 4 (30.8%), while 4 (30.8%) children died, while in children with NS and normal renal functions, CR was obtained in 3(14.2%), partial remission (PR) in 10(47.6%),CKD in 4(19%), and ESRD in 3 (14.3%).Outcome of cases presenting as RPGN was CR in 13 (44.8%), CKD in 2(6.9%) and ESRD in 7(24.1%) cases. Four children (13.8%) were lost to follow-up, while 3(10.3%) died. CONCLUSIONS: Children with MCGN presenting clinically with NS with impaired renal functions have worst outcome.

Screening of the LAMB2, WT1, NPHS1, and NPHS2 Genes in Pediatric Nephrotic Syndrome.

Mutations in the NPHS1, NPHS2, LAMB2, and the WT1 genes are responsible for causing nephrotic syndrome (NS) in two third of the early onset cases. This study was carried out to assess the frequencies of mutations in these genes in a cohort of pediatric NS patients. A total of 64 pediatric familial or sporadic SRNS cases were recruited. Among these, 74% had a disease onset of up to 3 years of age. We found one homozygous frameshift mutation in the NPHS1 gene in one CNS case and two homozygous mutations in the NPHS2 gene. Six mutations in four cases in the LAMB2 gene were also identified. No mutation was detected in the WT1 gene in isolated SRNS cases. LAMB2 gene missense mutations were segregating in NS cases with no extra-renal abnormalities. Analysis of the population genomic data (1000 genome and gnomAD databases) for the prevalence estimation revealed that NS is more prevalent than previously determined from clinical cohorts especially in Asian population compared with overall world populations (prevalence worldwide was 1in 189036 and in South-Asian was 1in 56689). Our results reiterated a low prevalence of mutations in the NPHS1, NPHS2, LAMB2, and WT1 genes in the studied population from Pakistan as compared to some European population that showed a high prevalence of mutations in these genes. This is a comprehensive screening of the genes causing early onset NS in sporadic and familial NS cases suggesting a more systematic and robust approach for mutation identification in all the 45 disease-causing genes in NS in our population is required.

Histopathological Spectrum and Short-Term Outcome of Treatment with Cyclophosphamide in Relapsing Steroid-Sensitive Nephrotic Syndrome.

OBJECTIVE: To determine the short-term outcome of cyclophosphamide (CPO) course in children with relapsing steroid sensitive nephrotic syndrome (SSNS) with different histopathological lesions. STUDY DESIGN: Descriptive, observational study. PLACE AND DURATION OF STUDY: Pediatric Nephrology Department, Sindh Institute of Urology and Transplantation, Karachi, from January 2012 to December 2014. METHODOLOGY: All children with relapsing steroid-sensitive nephrotic syndrome, who underwent renal biopsy and received cyclophosphamide therapy, were included and followed up for 2 years. Histopathological features in renal biopsy, duration of treatment, duration of complete remission and complication frequency was noted. RESULTS: Of the total 74 patients, 47 (63.5%) were males and 27 (36.5%) females. Median age with Interquartile range (IQR) at presentation was 5 years (4-7 years). Minimal change disease (MCD) was the most common histopathological diagnosis (n=54, 73%) followed by focal segmental glomerulosclerosis (FSGS) (n=13, 17.5%), mesangioproliferative glomerulonephritis(MesPGN) (n=6, 8.1%), IgA nephropathy (n=1, 1.4%). The median number of glomeruli included in each biopsy sample was 15. The median duration of treatment with CPO was 11 weeks (9 to 13 weeks), whereas the median duration of complete remission post-therapy was 13 months (7-23 months). A median timeframe of 17 months (13-24.2 months) lapsed between establishing the diagnosis of NS and initiating CPO treatment. Leucopenia was noted in six (8.1%) patients. CONCLUSION: The short-term outcome of relapsing SSNS can be improved with CPO and steroids, with minimum short-term side effects.

Whole exome sequencing frequently detects a monogenic cause in early onset nephrolithiasis and nephrocalcinosis.

The incidence of nephrolithiasis continues to rise. Previously, we showed that a monogenic cause could be detected in 11.4% of individuals with adult-onset nephrolithiasis or nephrocalcinosis and in 16.7-20.8% of individuals with onset before 18 years of age, using gene panel sequencing of 30 genes known to cause nephrolithiasis/nephrocalcinosis. To overcome the limitations of panel sequencing, we utilized whole exome sequencing in 51 families, who presented before age 25 years with at least one renal stone or with a renal ultrasound finding of nephrocalcinosis to identify the underlying molecular genetic cause of disease. In 15 of 51 families, we detected a monogenic causative mutation by whole exome sequencing. A mutation in seven recessive genes (AGXT, ATP6V1B1, CLDN16, CLDN19, GRHPR, SLC3A1, SLC12A1), in one dominant gene (SLC9A3R1), and in one gene (SLC34A1) with both recessive and dominant inheritance was detected. Seven of the 19 different mutations were not previously described as disease-causing. In one family, a causative mutation in one of 117 genes that may represent phenocopies of nephrolithiasis-causing genes was detected. In nine of 15 families, the genetic diagnosis may have specific implications for stone management and prevention. Several factors that correlated with the higher detection rate in our cohort were younger age at onset of nephrolithiasis/nephrocalcinosis, presence of multiple affected members in a family, and presence of consanguinity. Thus, we established whole exome sequencing as an efficient approach toward a molecular genetic diagnosis in individuals with nephrolithiasis/nephrocalcinosis who manifest before age 25 years.

Whole Exome Sequencing of Patients with Steroid-Resistant Nephrotic Syndrome.

BACKGROUND AND OBJECTIVES: Steroid-resistant nephrotic syndrome overwhelmingly progresses to ESRD. More than 30 monogenic genes have been identified to cause steroid-resistant nephrotic syndrome. We previously detected causative mutations using targeted panel sequencing in 30% of patients with steroid-resistant nephrotic syndrome. Panel sequencing has a number of limitations when compared with whole exome sequencing. We employed whole exome sequencing to detect monogenic causes of steroid-resistant nephrotic syndrome in an international cohort of 300 families. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Three hundred thirty-five individuals with steroid-resistant nephrotic syndrome from 300 families were recruited from April of 1998 to June of 2016. Age of onset was restricted to <25 years of age. Exome data were evaluated for 33 known monogenic steroid-resistant nephrotic syndrome genes. RESULTS: In 74 of 300 families (25%), we identified a causative mutation in one of 20 genes known to cause steroid-resistant nephrotic syndrome. In 11 families (3.7%), we detected a mutation in a gene that causes a phenocopy of steroid-resistant nephrotic syndrome. This is consistent with our previously published identification of mutations using a panel approach. We detected a causative mutation in a known steroid-resistant nephrotic syndrome gene in 38% of consanguineous families and in 13% of nonconsanguineous families, and 48% of children with congenital nephrotic syndrome. A total of 68 different mutations were detected in 20 of 33 steroid-resistant nephrotic syndrome genes. Fifteen of these mutations were novel. NPHS1, PLCE1, NPHS2, and SMARCAL1 were the most common genes in which we detected a mutation. In another 28% of families, we detected mutations in one or more candidate genes for steroid-resistant nephrotic syndrome. CONCLUSIONS: Whole exome sequencing is a sensitive approach toward diagnosis of monogenic causes of steroid-resistant nephrotic syndrome. A molecular genetic diagnosis of steroid-resistant nephrotic syndrome may have important consequences for the management of treatment and kidney transplantation in steroid-resistant nephrotic syndrome.

Mutations in sphingosine-1-phosphate lyase cause nephrosis with ichthyosis and adrenal insufficiency.

Steroid-resistant nephrotic syndrome (SRNS) causes 15% of chronic kidney disease cases. A mutation in 1 of over 40 monogenic genes can be detected in approximately 30% of individuals with SRNS whose symptoms manifest before 25 years of age. However, in many patients, the genetic etiology remains unknown. Here, we have performed whole exome sequencing to identify recessive causes of SRNS. In 7 families with SRNS and facultative ichthyosis, adrenal insufficiency, immunodeficiency, and neurological defects, we identified 9 different recessive mutations in SGPL1, which encodes sphingosine-1-phosphate (S1P) lyase. All mutations resulted in reduced or absent SGPL1 protein and/or enzyme activity. Overexpression of cDNA representing SGPL1 mutations resulted in subcellular mislocalization of SGPL1. Furthermore, expression of WT human SGPL1 rescued growth of SGPL1-deficient dpl1Δ yeast strains, whereas expression of disease-associated variants did not. Immunofluorescence revealed SGPL1 expression in mouse podocytes and mesangial cells. Knockdown of Sgpl1 in rat mesangial cells inhibited cell migration, which was partially rescued by VPC23109, an S1P receptor antagonist. In Drosophila, Sply mutants, which lack SGPL1, displayed a phenotype reminiscent of nephrotic syndrome in nephrocytes. WT Sply, but not the disease-associated variants, rescued this phenotype. Together, these results indicate that SGPL1 mutations cause a syndromic form of SRNS.