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Historically, specific mutations in WT1 gene have been associated with distinct syndromes based on phenotypic characteristics, including Denys-Drash syndrome (DDS), Frasier syndrome (FS), Meacham syndrome, and WAGR syndrome. DDS is classically defined by the triad of steroid-resistant nephrotic syndrome (SRNS) onset in the first year of life, disorders of sex development (DSD), and a predisposition to Wilms tumor (WT). Currently, a paradigm shift acknowledges a diverse spectrum of presentations beyond traditional syndromic definitions. Consequently, the concept of WT1-related disorders becomes more precise. A genotype–phenotype correlation has been established, emphasizing that the location and type of WT1 mutations significantly influence the clinical presentation, the condition severity, and the chronology of patient manifestations. Individuals presenting with persistent proteinuria, with or without nephrotic syndrome, and varying degrees of kidney dysfunction accompanied by genital malformations should prompt suspicion of WT1 mutations. Recent genetic advances enable a more accurate estimation of malignancy risk in these patients, facilitating a conservative nephron-sparing surgery (NSS) approach in select cases, with a focus on preserving residual kidney function and delaying nephrectomies. Other key management strategies include kidney transplantation and addressing DSD and gonadoblastoma. In summary, recent genetic insights underscore the imperative to implement individualized, integrated, and multidisciplinary management strategies for WT1-related disorders. This approach is pivotal in optimizing patient outcomes and addressing the complexities associated with these diverse clinical manifestations. [ABSTRACT FROM AUTHOR]

The article presents a case study of a critically ill infant with atypical genital appearance and progressive renal failure, ultimately diagnosed with Denys-Drash syndrome (DDS). Topics discussed include the differential diagnosis of congenital adrenal hyperplasia (CAH) versus DDS, the challenges in newborn screening for CAH, and the implications of timely diagnosis and management of rare genetic disorders.

Background : Nephropathy in Denys–Drash syndrome (DDS) develops within a few months of birth, often progressing to kidney failure. Wilms tumors also develop at an early age with a high rate of incidence. When a patient does not have Wilms tumor but develops kidney failure, prophylactic bilateral nephrectomy, and kidney transplantation (KTX) is an optimal approach owing to the high risk of Wilms tumor development. In the case presented here, prophylactic bilateral nephrectomy and KTX were performed in a patient who had not developed Wilms tumor or kidney failure. However, the treatment option is controversial as it involves the removal of a tumor-free kidney and performing KTX in the absence of kidney failure. Case diagnosis/treatment: We present the case of a 7-year-old boy, born at 38 weeks gestation. Examinations at the age of 1 year revealed severe proteinuria and abnormal internal and external genitalia. Genetic testing identified a missense mutation in exon 9 of the WT1 gene, leading to the diagnosis of DDS. At the age of 6 years, he had not yet developed Wilms tumor and had grown to a size that allowed him to safely undergo a KTX. His kidney function was slowly deteriorating (chronic kidney disease (CKD) stage 3), but he had not yet developed kidney failure. Two treatment options were considered for this patient: observation until the development of kidney failure or prophylactic bilateral nephrectomy with KTX to avoid Wilms tumor development. After a detailed explanation of options to the patient and family, they decided to proceed with prophylactic bilateral nephrectomy and KTX. At the latest follow-up 4 months after KTX, the patient's kidney functioned well without proteinuria. Conclusion: We performed prophylactic bilateral nephrectomy with KTX on a DDS patient who had not developed kidney failure or Wilms tumor by the age of 7 years. Although the risk of development of Wilms tumor in such a patient is unclear, this treatment may be an optimal approach for patients who are physically able to undergo KTX, considering the potentially lethal nature of Wilms tumor in CKD patients. [ABSTRACT FROM AUTHOR]

ObjectiveThis study aims to explore the association between different genotypes of WT1 gene variations and the phenotypes of Denys-Drash syndrome (DDS) and Frasier syndrome (FS).MethodsThrough searching and summarizing the case information of WT1 gene variations recorded in NCBI PubMed and CNKI databases from January 1, 1991 to October 31, 2023, we analyzed the association between variation types, occurrence locations, and phenotypes such as progressive renal function impairment, genitourinary developmental abnormalities, nephroblastoma, and gonadal tumors between DDS and FS.ResultsA total of 128 articles, including 304 subjects, were included in this study, and 86 pathogenic variations of the WT1 gene were detected.The distribution characteristics of these variations were as follows: the most common occurrence was in exon 9(24/86, 27.9%) and exon 8 (23/86, 26.7%); the most common variation type was missense mutation(51/86, 59.3%), followed by splice site mutation (13/86, 15.1%).The disease types caused by WT1 gene variations were as follows: DDS had the highest number of cases (174/304, 57.2%), followed by FS (83/304, 27.3%); DDS was mainly caused by missense mutations on exon 9 and exon 8 (143/174, 82.2%), while FS was mainly caused by splice site mutations on intron 9 (76/83, 91.6%).ConclusionsThe missense variants in exon 9 and exon 8 on the WT1 gene mainly resulted in DDS, while the splice variants in intron 9 mainly resulted in FS. Infants and children with progressive renal injury should undergo a comprehensive evaluation of the genitourinary system, and early genetic diagnosis should be established to improve prognosis.

A 6-year-old boy was diagnosed with chromosomal abnormalities (48,XYY, + 21[11]/46,XY[19]) at 4 months of age after a physical examination revealed an undescended testis and a dwarf penis. He also had mild renal dysfunction and severe proteinuria, and kidney biopsy at 2 years of age revealed focal segmental glomerulosclerosis. Genetic analysis to investigate suspected WT1 gene abnormalities revealed a novel variant in NM_024426.6:exon10:c.1506 T > A (p.(Asp502Glu)). His kidney function deteriorated rapidly, leading to the induction of peritoneal dialysis at 5 years of age. Although this variant had not been previously reported, bilateral nephrectomy was performed to prevent any progression of the tumor. Histopathology showed all the glomeruli observed within the observation area to be completely sclerotic, while also showing evidence of embryonal hyperplasia. This case was not a hot spot for Denys-Drash syndrome, but it had a similar phenotype and pathology that could have been derived from a WT1 gene abnormality. [ABSTRACT FROM AUTHOR]

Background Denys-Drash syndrome (DDS) is a rare disease characterized with pseudohermaphroditism, nephroblastoma (also known as Wilms tumor), and diffuse mesangial sclerosis. The therapy for DDS is largely supportive, i.e. surgery and chemotherapy for Wilms tumor and renal replacement therapy. Due to the limited understanding of the pathogenesis, precision therapy for DDS is yet to be explored. We sought to explore the cellular components and interactions in kidney tissues from an infant with DDS. Methods Whole-exome sequencing was performed to examine the mutations associated with DDS. Single-cell RNA sequencing (scRNA-seq) was performed to explore the heterogenicity of kidney tissue samples. Results A 6-month-old infant with bilateral Wilms tumors and genital ambiguity was diagnosed as having DDS. Whole exome sequencing revealed a novel de novo mutation (p.F185fs*118) in exon 1 of WT1. scRNA-seq was performed in tissue samples from bilateral Wilms tumors and the normal kidney from this infant. Fibroblasts, myocytes, epithelial cells, endothelial cells, and mononuclear phagocytes (MPs) ranked at the top of the 31   135 total cells. Fibroblasts and myocytes were dominant in the Wilms tumor samples. In contrast, most epithelial cells and endothelial cells were found in normal kidney tissues. CD44 and TUBA1A were significantly changed in myocyte subclusters, which may contribute to chemotherapy drug resistance. Macrophages intensively interacted with cancerous cells, including fibroblasts, epithelial cells, and myocytes. Conclusions A novel mutation (p.F185fs*118) in exon 1 of WT1 was identified in an infant with DDS. scRNA-Seq revealed the heterogenicity of cellular components in Wilms tumors and kidney tissues, shedding light on the pathogenesis of DDS. [ABSTRACT FROM AUTHOR]

IntroductionThis study aimed to analyze the clinical characteristics of nephropathy associated with WT1 gene mutations in Chinese children and explore the relationship between genotype and clinical phenotype.MethodsCases diagnosed at the Guangzhou Women and Children's Medical Center, were combined with those retrieved from PubMed and China National Knowledge Infrastructure (CNKI) databases from January 2015 to June 2022 and integrated into a study cohort; grouped according to gene mutation sites, clinical phenotype, and renal pathological types. The clinical characteristics between groups were compared, and the relationship between genotype and age of onset, clinical phenotype, and pathological type were retrospectively analyzed.ResultsThe center enrolled 15 confirmed children: seven cases of non-simple nephropathy, including Denys-Drash syndrome (DDS) and Frasier syndrome (FS); eight cases of isolated steroid-resistant nephrotic syndrome (ISRNS); and 13 cases (86.7%) that progressed to end-stage renal disease (ESRD). The initial hemoglobin and bicarbonate levels of patients with clinical non-simple nephropathy were significantly lower than those with simple nephropathy, whereas the serum creatinine levels were higher than those of patients with simple nephropathy. A total of 75 cases of nephropathy associated with WT1 mutations in the study cohort met the inclusion and exclusion criteria. The most common clinical manifestations of WT1 mutations in this cohort were DDS (29/75, 38.7%) and ISRNS (37/75, 49.3%). A renal biopsy was performed in 43 patients, and the common types of renal pathology were focal segmental glomerulosclerosis (23/43, 53.5%) and DMS (13/43, 30.2%). Within the cohort, there were 12 cases (16.0%) in the exon 8 mutation group, 32 (42.6%) in the exon 9 group, 19 (25.3%) in the intron 9 group, and 12 (16.0%) in other gene site mutation groups. Common sites of WT1 mutations in Chinese children were exons 9 and intron 9. Exon 8 mutations were uniquely correlated with the age of onset within three months [5/7; 71.4%; Adjusted standardized residual (AR) = 4.2]. The renal survival time in the exon 8 mutation group was the shortest (P = 0.003).DiscussionThe molecular and biological characteristics of WT1 mutation-related nephropathy determine the clinical type, pathological features, and renal survival time of the disease; and there was a strong correlation between the genotype and clinical phenotype.

The article provides an answer to a question related to early‑onset nephrotic syndrome and differential diagnoses of the disease.

Atypical hemolytic uremic syndrome (aHUS) is a life‑threatening condition characterized by microangiopathic hemolytic anemia, thrombocytopenia, as well as acute kidney injury (AKI). It can occur primarily due to complement gene mutations or secondary to another underlying condition. Several cases with Wilms' tumor gene 1 (WT1) mutations that presented with aHUS have been reported. Here, we report four cases of children diagnosed with WT1 mutations and presented initially with aHUS. There are two boys and two girls who presented with thrombotic microangiopathy (TMA), high lactate dehydrogenase, fragmented red blood cell (RBCs), and severe hypertension. All of them were anuric from the first presentation. Therapy with C5 inhibitors was initiated immediately and was associated with hematological remission without renal recovery. Renal replacement therapy (RRT) was started for all of the patients. A renal biopsy was conducted on two patients and showed global glomerulosclerosis. A genetic study identified pathogenic mutations in the WT1 gene. Two of the patients became dialysis dependent, and two patients underwent renal transplantation without the recurrence of aHUS. Our case series emphasizes that a diagnosis of WT1 mutation can be considered in children with aHUS with severe renal manifestations without a response to C5 inhibitors and with global glomerulosclerosis on renal biopsy. To our knowledge, this is the first report of a series of cases of WT1 mutations in pediatric patients presenting with clinical manifestation manifestations of aHUS. This unique finding highlights an association between HUS and WT1 mutation., Competing Interests: Human subjects: All authors have confirmed that this study did not involve human participants or tissue. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2024, Al Zabali et al.)

We describe a 46,XX girl with Denys-Drash syndrome, showing both kidney disease and genital abnormalities, in whom a misdiagnosis of hyperandrogenism was made. A 15 year-old girl was affected by neonatal nephrotic syndrome, progressing to end stage kidney failure. Hair loss and voice deepening were noted during puberty. Pelvic ultrasound and magnetic resonance imaging showed utero-tubaric agenesis, vaginal atresia and urogenital sinus, with inguinal gonads. Gonadotrophin and estradiol levels were normal, but testosterone was increased up to 285 ng/dL at Tanner stage 3. She underwent prophylactic gonadectomy. Histopathology reported fibrotic ovarian cortex containing numerous follicles in different maturation stages and rudimental remnants of Fallopian tubes. No features of gonadoblastoma were detected. Unexpectedly, testosterone levels were elevated four months after gonadectomy (157 ng/dL). Recent medical history revealed chronic daily comsumption of high dose biotin, as a therapeutic support for hair loss. Laboratory immunoassay instruments used streptavidin-biotin interaction to detect hormones and, in competitive immunoassays, high concentrations of biotin can result in false high results. Total testosterone, measured using liquid chromatography tandem mass spectrometry, was within reference intervals. Similar testosterone levels were detected on repeat immunoassay two weeks after biotin uptake interruption. Discordance between clinical presentation and biochemical results in patients taking biotin, should raise the suspicion of erroneous results. Improved communication among patients, health care providers, and laboratory professionals is required concerning the likelihood of biotin interference with immunoassays

Wilm's Tumor (WT) is the most common pediatric kidney cancer. Whereas most WTs are isolated, approximately 5% are associated with syndromes such as Denys-Drash (DDS), characterized by early onset nephropathy, disorders of sex development and predisposition to WT. A 46,XY patient presenting with bilateral WT and genital ambiguity without nephropathy was heterozygous for the novel c.851_854dup variant in WT1 gene sequence. This variant affects the protein generating the frameshift p.(Ser285Argfs*14) that disrupts a nuclear localization signal (NLS) region. This molecular finding is compatible with the severe scenario regarding the Wilm's tumor presented by the patient even though nephropathy was absent. [ABSTRACT FROM AUTHOR]

Background: Wilms tumour (WT) survivors, especially patients with associated syndromes or genitourinary anomalies due to constitutional WT1 pathogenic variant, have increased risk of kidney failure. We describe the long-term kidney function in children with WT and WT1 pathogenic variant to inform the surgical strategy and oncological management of such complex children. Methods: Retrospective analysis of patients with WT and constitutional WT1 pathogenic variant treated at a single centre between 1993 and 2016, reviewing genotype, phenotype, tumour histology, laterality, treatment, patient survival, and kidney outcome. Results: We identified 25 patients (60% male, median age at diagnosis 14 months, range 4–74 months) with WT1 deletion (4), missense (2), nonsense (8), frameshift (7), or splice site (4) pathogenic variant. Thirteen (52%) had bilateral disease, 3 (12%) had WT-aniridia, 1 had incomplete Denys-Drash syndrome, 11 (44%) had genitourinary malformation, and 10 (40%) had no phenotypic anomalies. Patient survival was 100% and 3 patients were in remission after relapse at median follow-up of 9 years. Seven patients (28%) commenced chronic dialysis of which 3 were after bilateral nephrectomies. The overall kidney survival for this cohort as mean time to start of dialysis was 13.38 years (95% CI: 10.3–16.4), where 7 patients experienced kidney failure at a median of 5.6 years. All of these 7 patients were subsequently transplanted. In addition, 2 patients have stage III and stage IV chronic kidney disease and 12 patients have albuminuria and/or treatment with ACE inhibitors. Four patients (3 frameshift; 1 WT1 deletion) had normal blood pressure and kidney function without proteinuria at follow-up from 1.5 to 12 years. Conclusions: Despite the known high risk of kidney disease in patients with WT and constitutional WT1 pathogenic variant, nearly two-thirds of patients had sustained native kidney function, suggesting that nephron-sparing surgery (NSS) should be attempted when possible without compromising oncological risk. Larger international studies are needed for accurate assessment of WT1genotype-kidney function phenotype correlation. [ABSTRACT FROM AUTHOR]

Wilms' tumor suppressor gene 1 (WT1) plays an essential role in urogenital and kidney development. Heterozygous germline pathogenic allelic variants of WT1 have been classically associated with Denys–Drash syndrome (DDS) and Frasier syndrome (FS). Usually, exonic pathogenic missense variants in the zinc finger region are the cause of DDS, whereas pathogenic variants affecting the canonic donor lysine-threonine-serine splice site in intron 9 cause FS. Phenotypic overlap between WT1 disorders has been frequently observed. New WT1 variant-associated phenotypes, such as 46,XX testicular/ovarian-testicular disorders of sex development (DSD) and primary ovarian insufficiency, have been reported. In this report, we describe the phenotypes and genotypes of 7 Brazilian patients with pathogenic WT1 variants. The molecular study involved Sanger sequencing and massively parallel targeted sequencing using a DSD-associated gene panel. Six patients (5 with a 46,XY karyotype and 1 with a 46,XX karyotype) were initially evaluated for atypical genitalia, and a 46,XY patient with normal female genitalia sought medical attention for primary amenorrhea. Germ cell tumors were identified in 2 patients, both with variants affecting alternative splicing of WT1 between exons 9 and 10. Two pathogenic missense WT1 variants were identified in two 46,XY individuals with Wilms' tumors; both patients were <1 year of age at the time of diagnosis. A novel WT1 variant, c.1453_1456 (p.Arg485Glyfs*14), was identified in a 46,XX patient with testicular DSD. Nephrotic proteinuria was diagnosed in all patients, including 3 who underwent renal transplantation after progressing to end-stage kidney disease. The expanding phenotypic spectrum associated with WT1 variants in XY and XX individuals confirms their pivotal role in gonadal and renal development as well as in tumorigenesis, emphasizing the clinical implications of these variants in genetic diagnosis. [ABSTRACT FROM AUTHOR]

Background: Although hypotension is a life-threatening complication of nephrectomy in children, risk factors for its development remain unknown. We evaluated the incidence, clinical course, and associated risk factors of pediatric post-nephrectomy hypotension in an observational study. Methods: This retrospective observational study included the clinical data of children who underwent nephrectomy in our center between 2002 and 2020. Patients undergoing nephrectomy at kidney transplantation and those who developed hypotension before nephrectomy were excluded. Results: The study included 55 nephrectomies in 51 patients, including 42 unilateral, 4 two-stage bilateral, and 5 simultaneous bilateral nephrectomies. The diagnoses were isolated Wilms tumor, neuroblastoma, congenital nephrotic syndrome, Denys-Drash syndrome, WAGR (Wilms tumor, aniridia, genitourinary malformations, and mental retardation) syndrome, and autosomal recessive polycystic kidney disease in 24, 10, 9, 6, 1, and 1 patient, respectively. Post-nephrectomy hypotension developed in 11 (20%) patients. Two patients (3.6%) had persistent hypotension; both had their kidneys resected, and one patient (1.8%) died. Male sex, kidney disease, resection of both kidneys, low estimated glomerular filtration rate, increased left ventricular posterior wall thickness in diastole, hypertension before nephrectomy, antihypertensive use, hyperreninemia, and hyperaldosteronism were significantly associated with post-nephrectomy hypotension. Multivariate logistic regression analysis revealed that hypertension before nephrectomy was the only significant risk factor for post-nephrectomy hypotension (P = 0.04). Conclusions: Hypertension before nephrectomy is a significant risk factor for pediatric post-nephrectomy hypotension. Life-threatening hypotension, which might occur after bilateral nephrectomy in infants, should be considered, especially in children with higher risks. [ABSTRACT FROM AUTHOR]

We describe a 46, XX girl with Denys-Drash syndrome, showing both kidney disease and genital abnormalities, in whom a misdiagnosis of hyperandrogenism was made. A 15 year-old girl was affected by neonatal nephrotic syndrome, progressing to end stage kidney failure. Hair loss and voice deepening were noted during puberty. Pelvic ultrasound and magnetic resonance imaging showed utero-tubaric agenesis, vaginal atresia and urogenital sinus, with inguinal gonads. Gonadotrophin and estradiol levels were normal, but testosterone was increased up to 285 ng/dL at Tanner stage 3. She underwent prophylactic gonadectomy. Histopathology reported fibrotic ovarian cortex containing numerous follicles in different maturation stages and rudimental remnants of Fallopian tubes. No features of gonadoblastoma were detected. Unexpectedly, testosterone levels were elevated four months after gonadectomy (157 ng/dL). Recent medical history revealed chronic daily comsumption of high dose biotin, as a therapeutic support for hair loss. Laboratory immunoassay instruments used streptavidin-biotin interaction to detect hormones and, in competitive immunoassays, high concentrations of biotin can result in false high results. Total testosterone, measured using liquid chromatography tandem mass spectrometry, was within reference intervals. Similar testosterone levels were detected on repeat immunoassay two weeks after biotin uptake interruption. Discordance between clinical presentation and biochemical results in patients taking biotin, should raise the suspicion of erroneous results. Improved communication among patients, health care providers, and laboratory professionals is required concerning the likelihood of biotin interference with immunoassays. [ABSTRACT FROM AUTHOR]

Denys-Drash syndrome is characterized by progressive nephropathy, gonadal dysgenesis, and Wilms tumor caused by a WT1 gene mutation. Infants with Denys-Drash syndrome frequently experience severe hypertension, but detailed clinical manifestations have yet to be clarified. Cases of infantile-onset Denys- Drash syndrome with severe hypertension at our hospital were retrospectively analyzed and the pathogenesis of hypertension was investigated. Six infants who received the diagnosis of Denys-Drash syndrome at the median age of 10 days (range: 2-182 days) were enrolled. Five infants had the complication of severe hypertension within a few days of diagnosis. All the patients showed rapid progression to end-stage renal disease and urgently required dialysis due to anuria/oliguria and hypervolemia with a median duration of 7.5 days (range: 0-17 days) on the day after diagnosis. Even under dialysis, all the patients continued to need antihypertensive treatment. Five patients underwent a preventive nephrectomy for Wilms tumor, and one patient underwent a nephrectomy due to progression to Wilms tumor. Two patients developed hypotension after a nephrectomy. The main causes of hypertension were hypervolemia in the predialysis stage, renin-associated hypertension in the dialysis stage, and multiple factors, including increased plasma catecholamine-associated hypertension in the postnephrectomy dialysis stage. At last the follow-up after bilateral nephrectomy, four of the five patients required antihypertensive treatment. Not all the patients showed target organ complications caused by hypertension. Severe hypertension is a common complication of infantile-onset Denys-Drash syndrome. The possibility of hypotension after nephrectomy should be considered in patients with Denys-Drash syndrome. [ABSTRACT FROM AUTHOR]

Background: Denys-Drash syndrome (DDS) is a very rare genetic disease. Wilms' tumor, genital abnormalities, and congenital glomerulopathy are the main features of DDS which resulted from a heterozygous mutation in the WT1 gene. Case Presentation: First case of DDS has been diagnosed in Saudi Arabia in four months newborn who admitted to nephrology department with ambiguous bilateral undescended testis, and nephropathy. On admission, he had normal vital signs except high blood pressure. His kidney function tests showed abnormal kidney function. Ultrasonography and MRI were done to figure out his nephropathy and undescended testis, respectively. Both Abdominal ultrasonography and kidney histopathology confirmed diffuse mesangial sclerosis (DMS). MRI graph located the un-identical ectopic testis. The autosomal dominant inherited pathogenic missense mutation in exon 9 of WT1 gene (c.1181G>A (p.Arg394GLu)) was confirmed by DNA direct sequencing analysis. At his 4th year of age, his nephropathy developed to End Stage Renal Disease (ESRD). Conclusion: DDS should be considered in new born baby with nephrotic syndrome and ambiguous gonads. DNA direct sequencing analysis for WT1 gene is very helpful for confirmation of DDS. [JBCGenetics 2018; 1(2.000): 84-86]

Abstract Background Hemolytic uremic syndrome (HUS) can occur as a primary process due to mutations in complement genes or secondary to another underlying disease. HUS sometimes occurs in the setting of glomerular diseases, and it has been described in association with Denys-Drash syndrome (DDS), which is characterized by the triad of abnormal genitourinary development; a pathognomonic glomerulopathy, diffuse mesangial sclerosis; and the development of Wilms tumor. Case presentation We report the case of a 46, XX female infant who presented with HUS and biopsy-proven thrombotic microangiopathy. Next generation sequencing of genes with known mutations causative of atypical HUS found that she was homozygous for the Complement Factor H H3 haplotype and heterozygous for a variant of unknown significance in the DGKE gene. Whole exome sequencing identified a de novo heterozygous WT1 c.1384C > T; p.R394W mutation, which is classically associated with Denys-Drash syndrome (DDS). At the time of bilateral nephrectomy five months after her initial biopsy, she had diffuse mesangial sclerosis, typical of Denys-Drash syndrome, without evidence of thrombotic microangiopathy. Conclusion This unique case highlights HUS as a rare but important manifestation of WT1 mutation and provides new insight into the genetics underlying this association.

Context: Synchronous Bilateral Wilms tumor (sBWT). Aims: This study aimed to assess the outcome of patients with sBWT treated on SIOP protocol. Settings and Design: Retrospective and prospective randomized study. Subjects and Methods: SIOP 93-01 protocol was used to study nine patients of sBWT in a single center and followed up over a period from 2 to 5 years. Statistical Analysis Used: Unpaired t-test and Mann–Whitney U-test were used for analysis. Results: Of nine patients, six were included in the study as three patients lost to follow-up. Among the six patients, there were four girls and two boys with a median age of 2 years. Mean regression in the size of tumor was 87% in four out of six patients. Tumor with unfavorable histology showed 32% response (ratio of favorable: unfavorable histology 2:1). Event-free survival rate was 81.3% and overall survival was 90% over 2–5 years. Recurrence was seen in two patients of whom one had Denys–Drash syndrome. Mean DTPA glomerular filtration rate was 91.4/ml/min/1.73 m2 preoperatively and that of 3 months after completion of treatment was 84/ml/min/1.73 m2. Health-related quality of life (HRQOL) using Pediatric Quality of Life Inventory and Lansky Play Performance Scale revealed significant improvement results of all functioning domains such as physical, social, emotional, and school subscales with P < 0.05 and performance scale (P < 0.04). Conclusions: We suggest SIOP protocol for sBWT and bilateral nephron-sparing surgery in two stages. However, long-term follow-up is required to assess the ultimate renal function outcome. HRQOL is an essential guide in improving the conditions of pediatric cancer survivors. [ABSTRACT FROM AUTHOR]

Background: Denys-Drash syndrome (DDS) is a rare disease characterized with pseudohermaphroditism, nephroblastoma (also known as Wilms tumor), and diffuse mesangial sclerosis. The therapy for DDS is largely supportive, i.e. surgery and chemotherapy for Wilms tumor and renal replacement therapy. Due to the limited understanding of the pathogenesis, precision therapy for DDS is yet to be explored. We sought to explore the cellular components and interactions in kidney tissues from an infant with DDS., Methods: Whole-exome sequencing was performed to examine the mutations associated with DDS. Single-cell RNA sequencing (scRNA-seq) was performed to explore the heterogenicity of kidney tissue samples., Results: A 6-month-old infant with bilateral Wilms tumors and genital ambiguity was diagnosed as having DDS. Whole exome sequencing revealed a novel de novo mutation (p.F185fs*118) in exon 1 of WT1 . scRNA-seq was performed in tissue samples from bilateral Wilms tumors and the normal kidney from this infant. Fibroblasts, myocytes, epithelial cells, endothelial cells, and mononuclear phagocytes (MPs) ranked at the top of the 31 135 total cells. Fibroblasts and myocytes were dominant in the Wilms tumor samples. In contrast, most epithelial cells and endothelial cells were found in normal kidney tissues. CD44 and TUBA1A were significantly changed in myocyte subclusters, which may contribute to chemotherapy drug resistance. Macrophages intensively interacted with cancerous cells, including fibroblasts, epithelial cells, and myocytes., Conclusions: A novel mutation (p.F185fs*118) in exon 1 of WT1 was identified in an infant with DDS. scRNA-Seq revealed the heterogenicity of cellular components in Wilms tumors and kidney tissues, shedding light on the pathogenesis of DDS., Competing Interests: The authors declare no conflict of interest., (© The Author(s) 2023. Published by Oxford University Press on behalf of the ERA.)

Background Hypomyelinating leukodystrophies represent an expanding group of neurogenetic disorders characterized primarily by central nervous system hypomyelination and variable neurological and non-neurological involvement. Hypomyelinating disorders have been rarely associated with gonadal dysfunction, being mainly represented by hypogonadotrophic hypogonadism in 4H syndrome. WT1 gene-associated disorders are classically associated with complex phenotypes including early carcinogenic risk for gonadoblastoma and Wilms' tumor, chronic renal failure, nephrotic syndrome and sex developmental disorders in intersex disorders and ambiguous genitalia. Methods The authors describe three non-related Brazilian patients with hypomyelinating leukodystrophy associated with complex neurological and systemic dysfunction with WT1 gene mutations. Results All described patients presented with similar neuroimaging features including thin corpus callosum, mild to moderate cerebellar atrophy and diffuse periventricular and profound hypomyelinating leukodystrophy involving supratentorial white matter with classical compromise linked to inherited non-somatic WT1 gene mutations in a similar pattern to Denys-Drash syndrome, including nephrotic syndrome with different glomerular disease, chronic renal failure, intersex disorder with ambiguous genitalia, and early occurrence of specific tumors, such as Wilms' tumor and gonadoblastoma. Conclusions Clinicians must include WT1 gene mutations in the differential diagnosis of hypomyelinating leukodystrophy with nephrotic syndrome, chronic renal failure, ambiguous genitalia or sex developmental disorders. [ABSTRACT FROM AUTHOR]

Vascular endothelial growth factor A (VEGF-A) is a prominent pro-angiogenic and pro-permeability factor in the kidney. Alternative splicing of the terminal exon of VEGF-A through the use of an alternative 30 splice site gives rise to a functionally different family of isoforms, termed VEGF-Axxxb, known to have anti-angiogenic and anti-permeability properties. Dysregulation of the VEGF-Axxx/VEGF-Axxxb isoform balance has recently been reported in several kidney pathologies, including diabetic nephropathy (DN) and Denys-Drash syndrome. Using mouse models of kidney disease where the VEGF-A isoform balance is disrupted, several reports have shown that VEGF-A165b treatment/over-expression in the kidney is therapeutically beneficial. Furthermore, inhibition of certain splice factor kinases involved in the regulation of VEGF-A terminal exon splicing has provided some mechanistic insight into how VEGF-A splicing could be regulated in the kidney. This review highlights the importance of further investigation into the novel area of VEGF-A splicing in chronic kidney disease pathogenesis and how future studies may allow for the development of splicing-modifying therapeutic drugs. [ABSTRACT FROM AUTHOR]

The article presents a case report of a 14-day-old newborn girl from unrelated healthy parents was admitted in the pediatric emergency department for grunting and anorexia. She had a past medical history of intrauterine growth retardation with normal morphological ultrasonography. She was born at 36 weeks of gestation following a triggered labor for anemias highlighted by ultrasonography.

WT1 gene mutations have been described in 46,XY patients with ambiguous genitalia or complete gonadal dysgenesis with or without Wilms' tumor, nephropathy, gonadoblastoma, and other defects, e.g., cryptorchidism or hypospadias. p.R462W is a hot spot mutation in exon 9 and is the most common mutation in patients with Denys-Drash syndrome. However, in this study we report an Egyptian patient with a novel phenotype carrying the p.R462W mutation. We also review the heterogeneity of phenotypes of previously reported patients with the p.R462W (previously referred to as Arg394Trp) mutation. [ABSTRACT FROM AUTHOR]

Background: Hemolytic uremic syndrome (HUS) can occur as a primary process due to mutations in complement genes or secondary to another underlying disease. HUS sometimes occurs in the setting of glomerular diseases, and it has been described in association with Denys-Drash syndrome (DDS), which is characterized by the triad of abnormal genitourinary development; a pathognomonic glomerulopathy, diffuse mesangial sclerosis; and the development of Wilms tumor.Case Presentation: We report the case of a 46, XX female infant who presented with HUS and biopsy-proven thrombotic microangiopathy. Next generation sequencing of genes with known mutations causative of atypical HUS found that she was homozygous for the Complement Factor H H3 haplotype and heterozygous for a variant of unknown significance in the DGKE gene. Whole exome sequencing identified a de novo heterozygous WT1 c.1384C > T; p.R394W mutation, which is classically associated with Denys-Drash syndrome (DDS). At the time of bilateral nephrectomy five months after her initial biopsy, she had diffuse mesangial sclerosis, typical of Denys-Drash syndrome, without evidence of thrombotic microangiopathy.Conclusion: This unique case highlights HUS as a rare but important manifestation of WT1 mutation and provides new insight into the genetics underlying this association. [ABSTRACT FROM AUTHOR]

Congenital nephrotic syndrome (CNS) caused by a mutation in the Wilms tumor 1 suppressor gene (WT1) is part of Denys Drash Syndrome or Frasier syndrome. In the framework of genetic counseling, the diagnosis of CNS can be refined with gene mutation studies on long-term stored formalin-fixed paraffin-embedded tissue from postmortem examination. We report a case of diffuse mesangial sclerosis with perinatal death caused by a de novo mutation in the WT1 gene in a girl with an XY-genotype. This is the first case of Denys Drash Syndrome with the uncommon missense c.1097G>A [p.(Arg366His)] mutation in the WT1 gene which has been diagnosed on long-term stored formalin-fixed paraffin-embedded tissue in 1993. This emphasizes the importance of retained and adequately stored tissue as a resource in the ongoing medical care and counseling. [ABSTRACT FROM AUTHOR]

Wilms tumour is named after Max Wilms. It is an embryonal tumour derived from the metanephros. It is the commonest childhood renal tumour and the third commonest paediatric malignancy. Synchronous bilateral Wilms tumours (BWT) represent 4-7% of all Wilms tumours (WT) and present at a younger age than unilateral Wilms tumours. At least 10% of synchronous BWTs have unfavourable histology, and up to 22% are associated with genitourinary abnormalities, aniridia, WAGR syndrome, Denys-Drash Syndrome, hemihypertrophy, or one of the other overgrowth syndromes. The long-term disease-free survival (DFS) rate for patients with unilateral Wilms' tumours is approaching 90%, and is around 70% for those with metastatic disease. For both synchronous and metachronous Wilms tumours the prognosis is less favourable with reported cure rates approaching 80% in the best centres and lower in resource poor settings. There is potential for a reduced quality of life due to renal insufficiency and the possible need for renal transplantation. The major clinical challenge in BWTs is preservation of functioning renal tissue using nephron sparing surgical techniques, while achieving cure with minimum therapy-related morbidity. Mortality is generally associated with progressive disease of anaplastic tumours. Chemotherapy followed by nephron sparing surgery has been able, in most cases, to eradicate the tumour while preserving renal function. Radiotherapy has largely been avoided because of fears of long term radiation injury to the residual functioning renal mass. Patient selection, appropriate pre- and post-operative chemotherapy and skilled surgical techniques all contribute to excellent outcomes where these are achievable. [ABSTRACT FROM AUTHOR]

Denys-Drash syndrome (DDS) is characterized by nephropa-thy, genital abnormalities, and predisposition to Wilms' tumor. DDS patients usually present heterozygous de novo germline WT1 mutations. The WT1 gene comprises 10 exons encoding the N-terminal transactivation and the C-terminal DNA-binding regions. Two unrelated patients with genital ambiguity and Wilms' tumor were analyzed by sequencing of the WT1 gene, and 3 mutations in exon 1 were identified of which 2 are novel. Patient 1 carried a c.555delC mutation that causes a frameshift and a premature stop codon. Patient 2 carried both c.421A>C and c.424C>T aberrations that lead to the missense p.Lys141Gln and the nonsense p.Lys142* mutation, respectively. As both patients were heterozygous for the mutations, we tested their parents who did not carry any mutation. Therefore, the 3 WT1 mutations occurred de novo in both patients. Heterozygous mutations result in WT1 haploinsufficiency as they impair protein production. They are associated with a milder DDS phenotype as observed in the patients studied here. [ABSTRACT FROM AUTHOR]

Introduction: This study aimed to analyze the clinical characteristics of nephropathy associated with WT1 gene mutations in Chinese children and explore the relationship between genotype and clinical phenotype., Methods: Cases diagnosed at the Guangzhou Women and Children's Medical Center, were combined with those retrieved from PubMed and China National Knowledge Infrastructure (CNKI) databases from January 2015 to June 2022 and integrated into a study cohort; grouped according to gene mutation sites, clinical phenotype, and renal pathological types. The clinical characteristics between groups were compared, and the relationship between genotype and age of onset, clinical phenotype, and pathological type were retrospectively analyzed., Results: The center enrolled 15 confirmed children: seven cases of non-simple nephropathy, including Denys-Drash syndrome (DDS) and Frasier syndrome (FS); eight cases of isolated steroid-resistant nephrotic syndrome (ISRNS); and 13 cases (86.7%) that progressed to end-stage renal disease (ESRD). The initial hemoglobin and bicarbonate levels of patients with clinical non-simple nephropathy were significantly lower than those with simple nephropathy, whereas the serum creatinine levels were higher than those of patients with simple nephropathy. A total of 75 cases of nephropathy associated with WT1 mutations in the study cohort met the inclusion and exclusion criteria. The most common clinical manifestations of WT1 mutations in this cohort were DDS (29/75, 38.7%) and ISRNS (37/75, 49.3%). A renal biopsy was performed in 43 patients, and the common types of renal pathology were focal segmental glomerulosclerosis (23/43, 53.5%) and DMS (13/43, 30.2%). Within the cohort, there were 12 cases (16.0%) in the exon 8 mutation group, 32 (42.6%) in the exon 9 group, 19 (25.3%) in the intron 9 group, and 12 (16.0%) in other gene site mutation groups. Common sites of WT1 mutations in Chinese children were exons 9 and intron 9. Exon 8 mutations were uniquely correlated with the age of onset within three months [5/7; 71.4%; Adjusted standardized residual (AR) = 4.2]. The renal survival time in the exon 8 mutation group was the shortest ( P  = 0.003)., Discussion: The molecular and biological characteristics of WT1 mutation-related nephropathy determine the clinical type, pathological features, and renal survival time of the disease; and there was a strong correlation between the genotype and clinical phenotype., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (© 2023 Chen, Zhang, Lin, Lu, Zhong, Zhong, Gao and Liao.)

The article discusses answers to a quiz that appeared within the issue of "Pediatric Nephrology," which focused on renal failure from birth. It is noted that through ultrasonography, having large bright kidneys are suggestive of acute kidney injury (AKI). Information about the Denys-Drash syndrome (DDS) is presented, which is caused by heterozygous mutations on WT1 on chromosome 11p13.

Background & objectives: Clinically, nephrotic syndrome (NS) is a diverse group of symptoms; about 20 per cent of NS cases are resistant to steroid treatment, and within ten years they progress to end-stage renal disease. The present study was undertaken to identify the mutations of Wilms' tumour 1 (WT1) gene in steroid-resistant NS (SRNS) children. Methods: A total of 173 children with SRNS and 100 children in the control group were enrolled in the study. DNA extraction was done, screened for WT1 (exons 8 and 9) gene amplified by polymerase chain reaction and direct sequencing. Karyotype analyses were done for WT1 mutation cases. Results: WT1 mutations were found in three of 173 SRNS cases (2 girls, 1 boy). All of them had intron 9 (IVS 9 + 4 C>T, 2; IVS + 5 G>A, 1) mutation. Of these three cases, one had familial and another two had sporadic history. Renal histology analysis showed two cases with focal segmental glomerulosclerosis (FSGS) and they had external female genitalia but 46,XY karyotype. Both of them had streak gonads. Of the three cases, one expired. Interpretation & conclusions: The findings of the present study indicate that all females with SRNS-FSGS should be screened for WT1 gene mutation to diagnose whether they have FS for possible gonadectomy. [ABSTRACT FROM AUTHOR]

Congenital nephrotic syndrome (CNS) caused by a mutation in the Wilms tumor 1 suppressor gene (WT1) is part of Denys Drash Syndrome or Frasier syndrome. In the framework of genetic counseling, the diagnosis of CNS can be refined with gene mutation studies on long-term stored formalin-fixed paraffin-embedded tissue from postmortem examination. We report a case of diffuse mesangial sclerosis with perinatal death caused by a de novo mutation in the WT1 gene in a girl with an XY-genotype. This is the first case of Denys Drash Syndrome with the uncommon missense c.1097G>A [p.(Arg366His)] mutation in the WT1 gene which has been diagnosed on long-term stored formalin-fixed paraffin-embedded tissue in 1993. This emphasizes the importance of retained and adequately stored tissue as a resource in the ongoing medical care and counseling. [ABSTRACT FROM PUBLISHER]

The WT1 transcription factor regulates SRY expression during the initial steps of the sex determination process in humans, activating a gene cascade leading to testis differentiation. In addition to causing Wilms' tumor, mutations in WT1 are often responsible for urogenital defects in men, while SRY mutations are mainly related to 46,XY pure gonadal dysgenesis. In order to evaluate their role in abnormal testicular organogenesis, we screened for SRY and WT1 gene mutations in 10 children with XY partial gonadal dysgenesis, 2 of whom with a history of Wilms' tumor. The open reading frame and 360 bp of the 5' flanking sequence of the SRY gene, and the ten exons and intron boundaries of the WT1 gene were amplified by PCR of genomic DNA. Single-strand conformation polymorphism was initially used for WT1 mutation screening. Since shifts in fragment migration were only observed for intron/exon 4, the ten WT1 exons from all patients were sequenced manually. No mutations were detected in the SRY 5' untranslated region or within SRY open-reading frame sequences. WT1 sequencing revealed one missense mutation (D396N) in the ninth exon of a patient who also had Wilms' tumor. In addition, two silent point mutations were found in the first exon including one described here for the first time. Some non-coding sequence variations were detected, representing one new (IVS4+85A>G) and two already described (-7ATG T>G, IVS9-49 T>C) single nucleotide polymorphisms. Therefore, mutations in two major genes required for gonadal development, SRY and WT1, are not responsible for XY partial gonadal dysgenesis.

Denys-Drash syndrome (DDS) is a combination of genital and urinary anomalies that are mostly associated with renal and gonadal malignancies. We report 2 patients who presented with genital ambiguity and were diagnosed as 46-XY DDS. Both patients had renal masses during follow-up and underwent partial nephrectomy aiming to have transplant at older age. [ABSTRACT FROM AUTHOR]