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Introduction Left ventricular hypertrophy (LVH) is the commonest myocardial response to chronic kidney disease (CKD); this response has been regarded detrimental as it impairs the blood flow to the deepest layers of the myocardium causing progressive myocardial dysfunction. The aim of these series is to assess the determinants of LVH in CKD patients and its impact on subendocardial function in such patients. Methods This study has been conducted on 40 CKD patients (Group 1) and 40 age-matched controls, both groups were assessed by transmural echocardiography to determine the subepicardial and subendocardial global longitudinal strain (GLS) as an expression of the systolic function of each of those layers. LVH was assessed by calculation of left ventricle mass index (LVMI). Both groups underwent ambulatory blood pressure monitoring. Group 1 was assessed as regards lipid profile and insulin resistance by homeostasis model assessment of insulin resistance (HOMA-IR). Results HOMA-IR proved to be a more important determinant of LV hypertrophy than SBP and DBP with a P of 0.01. Moreover subendocardial GLS was negatively correlated with LVMI with r = 0.69 and P < 0.01 denoting the negative effect. LVH plays on subendocardial function probably by impairing myocardial perfusion. Conclusion This study points toward the importance of insulin resistance in aggravation of myocardial remodeling in CKD patients; more studies are warranted to examine the role of insulin Sensitizers in reversing such remodeling and restoring subendocardial function in such important systemic disorder.

Nephrotic syndrome (NS) is a leading cause of chronic kidney disease. We found recessive NOS1AP variants in two families with early-onset NS by exome sequencing. Overexpression of wild-type (WT) NOS1AP, but not cDNA constructs bearing patient variants, increased active CDC42 and promoted filopodia and podosome formation. Pharmacologic inhibition of CDC42 or its effectors, formin proteins, reduced NOS1AP-induced filopodia formation. NOS1AP knockdown reduced podocyte migration rate (PMR), which was rescued by overexpression of WT Nos1ap but not by constructs bearing patient variants. PMR in NOS1AP knockdown podocytes was also rescued by constitutively active CDC42Q61L or the formin DIAPH3 Modeling a NOS1AP patient variant in knock-in human kidney organoids revealed malformed glomeruli with increased apoptosis. Nos1apEx3-/Ex3- mice recapitulated the human phenotype, exhibiting proteinuria, foot process effacement, and glomerulosclerosis. These findings demonstrate that recessive NOS1AP variants impair CDC42/DIAPH-dependent actin remodeling, cause aberrant organoid glomerulogenesis, and lead to a glomerulopathy in humans and mice.

Nephrotic syndrome (NS) is a leading cause of chronic kidney disease. We found recessive

Walker-Warburg syndrome (WWS) is a severe form of congenital muscular dystrophy (CMD) secondary to α-dystroglycanopathy with muscle, brain and eye abnormalities often leading to death in the first weeks of life. It is transmitted in an autosomal recessive pattern, and has been linked to at least fifteen different genes; including protein O-mannosyltransferase 1 (POMT1), protein O-mannosyltransferase 2 (POMT2), protein O-mannose beta-1,2-N acetylglucosaminyltransferase (POMGNT1) gene, the fukutin (FKTN) gene, the fukutin-related protein (FKRP) gene, the LARGE gene, the isoprenoid synthase domain-containing (ISPD) gene and other genes. We report on a family having four consecutive siblings affected by this condition with lethal outcome in three of them, and terminated pregnancy of the fourth based on antenatal fetal MRI complex brain and kidney anomalies that heralded proper and deep clinical phenotyping. The diagnosis of WWS was suggested based on the unique collective phenotype comprising neurological involvement in the form of lissencephaly, subcortical/subependymal heterotopia and cerebellar hypoplasia shared by all four siblings, microphthalmia in one sibling, and large cystic kidneys in the fetus and another sibling. Other unshared neurological abnormalities included hydrocephalus and Dandy-Walker malformation. By whole exome sequencing of the proband fetus, we identified a highly conserved missense mutation in the POMT2 gene that is known to cause congenital muscular dystrophy-dystroglycanopathy with brain and eye anomalies, and Walker-Warburg syndrome. In conclusion, the heterogenous clinical presentation in the four affected siblings of this consanguineous family with POMT2 mutation expands the current clinical spectrum of POMT2 associated WWS to include large cystic kidneys; and further confirms intra-familial variability in terms of brain, kidney, and eye anomalies.

Purpose The aim of the present study was to assess visual acuity, measure the degree of visual impairment, and examine fundus changes in Egyptian children with Bardet-Biedl syndrome (BBS), and to correlate these findings with the results of flash electroretinography (ERG). Materials and methods A cross-sectional study was conducted on infants and children with BBS. Diagnosis was carried out by a specialized pediatrician. Full ophthalmological examination, including slit-lamp examination, refraction, and indirect ophthalmoscopy, was carried out. Best-corrected visual acuity was measured and full-field flash ERG was performed. Results This study included 20 patients with BBS. The median age was 9 years (ranged from 1 day to 18 years). The mean age of onset of symptoms in the whole group was 6.5 ± 4.3 years. Visual impairment, defined as a best-corrected visual acuity in the better seeing eye of 20/60 (6/18) or less, was present in 11 patients (55% of the cases), and night blindness as a symptom was present in nine patients (45%); pigmentary retinopathy was clinically detected in 35% of the patients and retinal dystrophy as an ERG finding was detected in 60% of the patients. Conclusion Visual impairment in BBS is mainly caused by rod-cone dystrophy, which is one of the major criterion of diagnosis, which manifests with age. Before the age of 6, children rarely present with ocular manifestations, and usually have normal fundus examination; on the other hand, retinitis pigmentosa-like picture is usually seen in children older than 6. However, the electrophysiological changes may precede the fundus changes.

OBJECTIVE: To identify prenatal, perinatal, and postnatal risk factors for dialysis within the first year of life in children with autosomal recessive polycystic kidney disease (ARPKD) as a basis for parental counseling after prenatal and perinatal diagnosis. STUDY DESIGN: A dataset comprising 385 patients from the ARegPKD international registry study was analyzed for potential risk markers for dialysis during the first year of life. RESULTS: Thirty-six out of 385 children (9.4%) commenced dialysis in the first year of life. According to multivariable Cox regression analysis, the presence of oligohydramnios or anhydramnios, prenatal kidney enlargement, a low Apgar score, and the need for postnatal breathing support were independently associated with an increased hazard ratio for requiring dialysis within the first year of life. The increased risk associated with Apgar score and perinatal assisted breathing was time-dependent and vanished after 5 and 8 months of life, respectively. The predicted probabilities for early dialysis varied from 1.5% (95% CI, 0.5%-4.1%) for patients with ARPKD with no prenatal sonographic abnormalities to 32.3% (95% CI, 22.2%-44.5%) in cases of documented oligohydramnios or anhydramnios, renal cysts, and enlarged kidneys. CONCLUSIONS: This study, which identified risk factors associated with onset of dialysis in ARPKD in the first year of life, may be helpful in prenatal parental counseling in cases of suspected ARPKD. ispartof: JOURNAL OF PEDIATRICS vol:199 pages:22-+ ispartof: location:United States status: published

Steroid Resistant Nephrotic Syndrome (SRNS) in children and young adults has differing etiologies with monogenic disease accounting for 2.9–30% in selected series. Using whole exome sequencing we sought to stratify a national population of children with SRNS into monogenic and non-monogenic forms, and further define those groups by detailed phenotypic analysis. Pediatric patients with SRNS were identified via a national United Kingdom Renal Registry. Whole exome sequencing was performed on 187 patients, of which 12% have a positive family history with a focus on the 53 genes currently known to be associated with nephrotic syndrome. Genetic findings were correlated with individual case disease characteristics. Disease causing variants were detected in 26.2% of patients. Most often this occurred in the three most common SRNS-associated genes: NPHS1 , NPHS2, and WT1 but also in 14 other genes. The genotype did not always correlate with expected phenotype since mutations in OCRL , COL4A3, and DGKE associated with specific syndromes were detected in patients with isolated renal disease. Analysis by primary/presumed compared with secondary steroid resistance found 30.8% monogenic disease in primary compared with none in secondary SRNS permitting further mechanistic stratification. Genetic SRNS progressed faster to end stage renal failure, with no documented disease recurrence post-transplantation within this cohort. Primary steroid resistance in which no gene mutation was identified had a 47.8% risk of recurrence. In this unbiased pediatric population, whole exome sequencing allowed screening of all current candidate genes. Thus, deep phenotyping combined with whole exome sequencing is an effective tool for early identification of SRNS etiology, yielding an evidence-based algorithm for clinical management.

Primary hyperoxalurias are rare inborn errors of metabolism resulting in increased endogenous production of oxalate that leads to excessive urinary oxalate excretion. Diagnosis of primary hyperoxaluria type 1 (PH1) is a challenging issue and depends on diverse diagnostic tools including biochemical analysis of urine, stone analysis, renal biopsy, genetic studies and in some cases liver biopsy for enzyme assay. We characterized the clinical presentation as well as renal and extrarenal phenotypes in PH1 patients.This descriptive cohort study included patients with presumable PH1 presenting with nephrolithiasis and/or nephrocalcinosis (NC). Precise clinical characterization of renal phenotype as well as systemic involvement is reported. AGXT mutational analysis was performed to confirm the diagnosis of PH1.The study cohort included 26 patients with presumable PH1 with male to female ratio of 1.4:1. The median age at time of diagnosis was 6 years, nevertheless the median age at initial symptoms was 3 years. Thirteen patients (50%) were diagnosed before the age of 5 years. Two patients had no symptoms and were diagnosed while screening siblings of index patients. Seventeen patients (65.4%) had reached end-stage renal disease (ESRD): 6/17 (35.3%) during infancy, 4/17 (23.5%) in early childhood and 7/17 (41.29%) in late childhood. Two patients (7.7%) had clinically manifest extra renal (retina, heart, bone, soft tissue) involvement. Mutational analysis of AGXT gene confirmed the diagnosis of PH1 in 15 out of 19 patients (79%) where analysis had been performed. Fifty percent of patients with maintained renal functions had projected 10 years renal survival.PH1 is a heterogeneous disease with wide spectrum of clinical, imaging and functional presentation. More than two-thirds of patients presented prior to the age of 5 years; half of them with the stormy course of infantile PH1. ESRD was the commonest presenting manifestation in two-thirds of our cohort.

Background: The term nephronophthisis-related ciliopathies (NPHP-RC) describes a group of rare autosomal-recessive cystic kidney diseases, characterised by broad genetic and clinical heterogeneity. NPHP-RC is frequently associated with extrarenal manifestations and accounts for the majority of genetically caused chronic kidney disease (CKD) during childhood and adolescence. Generation of a molecular diagnosis has been impaired by this broad genetic heterogeneity. However, recently developed high-throughput exon sequencing techniques represent powerful and efficient tools to screen large cohorts for dozens of causative genes. Methods: Therefore, we performed massively multiplexed targeted sequencing using the modified molecular inversion probe strategy (MIPs) in an international cohort of 384 patients diagnosed with NPHP-RC. Results: As a result, we established the molecular diagnoses in 81/384 unrelated individuals (21.1%). We detected 127 likely disease-causing mutations in 18 of 34 evaluated NPHP-RC genes, 22 of which were novel. We further compared a subgroup of current findings to the results of a previous study in which we used an array-based microfluidic PCR technology in the same cohort. While 78 likely disease-causing mutations were previously detected by the array-based microfluidic PCR, the MIPs approach identified 94 likely pathogenic mutations. Compared with the previous approach, MIPs redetected 66 out of 78 variants and 28 previously unidentified variants, for a total of 94 variants. Conclusions: In summary, we demonstrate that the modified MIPs technology is a useful approach to screen large cohorts for a multitude of established NPHP genes in order to identify the underlying molecular cause. Combined application of two independent library preparation and sequencing techniques, however, may still be indicated for Mendelian diseases with extensive genetic heterogeneity in order to further increase diagnostic sensitivity.

Autosomal recessive polycystic kidney disease (ARPKD) is an inherited ciliopathy leading to progressive kidney and liver disease. Biallelic mutations in the PKHD1 gene underlie this condition. We describe a child with bilaterally enlarged cystic kidneys, portal hypertension, and cerebral ventriculomegaly. Molecular genetic investigations using whole-exome sequencing and confirmation using Sanger sequencing revealed a homozygous pathogenic mutation in PKHD1 underlying the clinical phenotype of ARPKD. Whole-exome data analysis was used to search for additional rare variants in additional ciliopathy genes that may have contributed to the unusual brain phenotype. Aside from a rare hypomorphic allele in MKS1, no other pathogenic variants were detected. We conclude that the homozygous pathogenic mutation in PKHD1 underlies the ciliopathy phenotype in this patient.

Background Nephropathic cystinosis is an inherited autosomal recessive lysosomal storage disorder characterized by the pathological accumulation and crystallization of cystine inside different cell types. WBC cystine determination forms the basis for the diagnosis and therapeutic monitoring with the cystine depleting drug (cysteamine). The chitotriosidase enzyme is a human chitinase, produced by activated macrophages. Its elevation is documented in several lysosomal storage disorders. Although, about 6% of Caucasians have enzyme deficiency due to homozygosity of 24-bp duplication mutation in the chitotriosidase gene, it is currently established as a screening marker and therapeutic monitor for Gaucher’s disease. Methods Plasma chitotriosidase activity was measured in 45 cystinotic patients, and compared with 87 healthy controls and 54 renal disease patients with different degrees of renal failure (CKD1-5). Chitotriosidase levels were also correlated with WBC cystine in 32 treated patients. Furthermore, we incubated control human macrophages in-vitro with different concentrations of cystine crystals and monitored the response of tumor necrosis factor-alpha (TNF-α) and chitotriosidase activity. We also compared plasma chitotriosidase activity in cystinotic knocked-out (n = 10) versus wild-type mice (n = 10). Results Plasma chitotriosidase activity in cystinotic patients (0–3880, median 163 nmol/ml/h) was significantly elevated compared to healthy controls (0–90, median 18 nmol/ml/h) and to CKD patients (0–321, median 52 nmol/ml/h), P

Renal cystic disorders (RCD) constitute an important and leading cause of end-stage renal disease (ESRD) in children. It can be acquired or inherited; isolated or associated with extrarenal manifestations. The precise diagnosis represents a difficult clinical challenge.The aim of this study was to define the pattern of clinical phenotypes of children with renal cystic diseases in Pediatric Nephrology Center, Cairo University. We have studied the clinical phenotypes of 105 children with RCD [45 (43%) of them had extrarenal manifestations].The most common disorders were the presumably inherited renal cystic diseases (65.7%) mainly nephronophthisis and related ciliopathies (36.2%), as well as polycystic kidney diseases (29.5%). Moreover, multicystic dysplastic kidneys accounted for 18% of study cases. Interestingly, eight syndromic cases are described, yet unclassified as none had been previously reported in the literature.RCD in this study had an expanded and complex spectrum and were largely due to presumably inherited/genetic disorders (65.7%). Moreover, we propose a modified algorithm for clinical and diagnostic approach to patients with RCD.

Nephronophthisis (NPHP) is a recessive disorder of the kidney that is the leading genetic cause of end-stage renal failure in children. Egypt is a country with a high rate of consan-guineous marriages; yet, only a few studies have investigated the clinical and molecular charac-teristics of NPHP and related ciliopathies in the Egyptian population. We studied 20 children, from 17 independent families, fulfilling the clinical and the ultrasonographic criteria of NPHP. Analysis for a homozygous deletion of the NPHP1 gene was performed by polymerase chain reaction on the genomic DNA of all patients. Patients were best categorized as 75% juvenile NPHP, 5% infantile NPHP, and 20% Joubert syndrome-related disorders (JSRD). The mean age at diagnosis was 87.5 + 45.4 months, which was significantly late as compared with the age at onset of symptoms, 43.8 ± 29.7 months (P

Sirs, Nephronophthisis (NPHP) is an autosomal recessive cystic kidney disease that constitutes the most frequent genetic cause for end-stage renal disease (ESRD) in the first three decades of life. Homozygous deletions in the NPHP1 gene account for approximately 21% of all NPHP cases, whereas the other genes contribute less than 3% each. Interestingly, positional cloning of the nine genes (NPHP 1 through 9) and functional characterization of their encoded proteins (nephrocystins) have contributed to a unifying theory that defines cystic kidney diseases as “ciliopathies” [1]. Since there are no clinical or molecular data about NPHP in Egyptian children, we investigated the prevalence of homozygous NPHP1 deletion among a cohort of children with presumptive diagnosis of NPHP at Center of Pediatric Nephrology & Transplantation (CPNT), Cairo University. We studied 20 children, from 17 independent families, fulfilling the clinical and the ultrasonographic criteria of NPHP. All patients had full ophthalmologic examination, brain MRI was carried out in children with neurological involvement. Analysis for a homozygous deletion of the NPHP1 gene was performed by multiplex polymerase chain reaction (PCR) approach on genomic DNA of patients described earlier [2]. Sex distribution among affected patients showed a slight preponderance of females, with a ratio of 1.2:1 (11 females and 9 males). Seventy five percent of our study patients were the products of consanguineous marriages, the percentage of affected siblings was strikingly high 65% (13/20 patients) and 40% (8/20 patients) had a history of sibling death due to a similar condition. Fifteen of 20 patients (75%) presented with signs of ESRD. All the patients suffered from anemia and growth retardation when they first came to medical attention. Nineteen of 20 patients (95%) had a history typical of nephronophthisis, with symptoms of polydipsia, polyuria, and secondary enuresis. Four of 20 patients (20%) were hypertensive with elevated blood pressure above the 95th percentile for age, gender, and height. Clinically, study patients were best categorized as: 13/20 (65%) patients with isolated juvenile NPHP, 3/20 (15%) patients as infantile NPHP, while the remaining 4/20 (20%) patients had extrarenal associations (molar tooth sign on brain MRI, ataxia, mental retardation, retinal dystrophy, oculomotor apraxia, and facial dysmorphy) hence were clinically categorized as Joubert Syndrome Related Disorder (JSRD). The mean age at diagnosis 87.5 + 45.4 months was significantly late as compared to the age of onset of symptoms 43.8 ± 29.7 months (P