Prophylactic bilateral nephrectomy and preemptive kidney transplantation for Denys-Drash syndrome prior to development of kidney failure.

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.

Bilateral Wilms' tumor in a child with Denys-Drash syndrome: novel frameshift variant disrupts the WT1 nuclear location signaling region.

OBJECTIVES: 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. CASE PRESENTATION: 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. CONCLUSIONS: This molecular finding is compatible with the severe scenario regarding the Wilm's tumor presented by the patient even though nephropathy was absent.

WT1 complete gonadal dysgenesis with membranoproliferative glomerulonephritis: case series and literature review.

BACKGROUND: Intronic WT1 mutations are usually causative of Frasier syndrome with focal segmental glomerulosclerosis as the characteristic nephropathy. Membranoproliferative glomerulonephritis is not commonly associated with disorders of sex development but has been recently identified as a WT1-associated nephropathy, but usually in cases of exonic mutations in either isolated Wilms tumor or Denys-Drash syndrome. METHODS: The clinical and genetic data from 3 individuals are reported. RESULTS: This report describes the kidney manifestations in 3 individuals from 2 unrelated families with Frasier syndrome intronic WT1 mutations, noting that 2 of the 3 individuals have histologically confirmed membranoproliferative glomerulonephritis. CONCLUSIONS: These case reports support expansion of the clinical spectrum of the kidney phenotypes associated with Frasier syndrome providing evidence of an association between WT1 mutation and an immune complex-related membranoproliferative glomerulonephritis. A higher resolution version of the Graphical abstract is available as Supplementary information.

New mutation in WT1 gene in a boy with an incomplete form of Denys-Drash syndrome: A CARE-compliant case report.

RATIONALE: Pediatric patients with WTl-associated syndromes (including Wilms' tumor-aniridia syndrome and Denys-Drash syndrome), Perlman syndrome, mosaic aneuploidy, and Fanconi anemia with a biallelic breast cancer type 2 susceptibility protein mutation have the highest risk of developing Wilms' tumor. PATIENT CONCERNS AND DIAGNOSIS: We describe a patient with bilateral metachronous Wilms' tumor, ambiguous genitalia characterized by 46, XY disorder of sexual development (DSD) with scrotal hypospadias and bilateral abdominal cryptorchidism, but without nephropathy. At the age of 7 months, the child underwent left nephrectomy with left orchiopexy. At follow-up after 8 months, a second tumor with a diameter of 10 mm was detected in abdominal CT scans at the lower pole of the right kidney. INTERVENTION: Intra-operative macroscopic inspection of the right kidney revealed a tight attachment of the right proximal ureter to the tumor. Thus, retroperitoneoscopic resection of the lower pole of the right kidney had to be changed to an open surgical procedure with partial resection of the proximal ureter and high uretero-ureterostomy. We subsequently performed orchiopexy and two-stage correction of hypospadias using a free skin graft. OUTCOMES: At the last follow-up at the age of 8 years, no pathology requiring treatment was noted. A pair-end-reading (2 × 125) DNA analysis with an average coverage of at least 70 to 100 × revealed a previously unknown heterozygous mutation in exon 7 of the Wilms' tumor suppressor gene 1 (WT1) gene (chr11:32417947G>A), leading to the appearance of a site of premature translation termination in codon 369 (p.Arg369Ter, NM_024426.4). This mutation had not been registered previously in the control samples "1000 genomes," Exome Sequencing Project 6500, and the Exome Aggregation Consortium. Thus, to the best of our knowledge this represents a newly identified mutation causing incomplete Denys-Drash syndrome.

A novel WT1 gene mutation in a chinese girl with denys-drash syndrome.

OBJECTIVE: Denys-Drash syndrome (DDS) is defined by the triad of Wilms tumor, nephrotic syndrome, and/or ambiguous genitalia. Genetic testing may help identify new gene mutation sites and play an important role in clinical decision-making. METHODS: We present a patient with an XY karyotype and female appearance, nephropathy, and Wilms tumor in the right kidney. Genomic DNA was extracted from peripheral blood cells according to standard protocols. "Next-generation" sequencing (NGS) was performed to identify novel variants. The variant was analyzed with Mutation Taster, and its function was explored by a cell growth inhibition assay. RESULTS: We found the first case of Denys-Drash syndrome with the uncommon missense mutation (c.1420C>T, p.His474 Tyr) in the WT1 gene. In silico analysis, the variant was predicted "disease-causing" by Mutation Taster. The mutated variant showed a weaker effect in inhibiting tumor cells than wild-type WT1. CONCLUSIONS: The uncommon missense mutation (c.1420C>T, p.His474 Tyr) in the WT1 gene may be a crucial marker in DDS.

Focal Segmental Membranoproliferative Glomerulonephritis: A Histological Variant of Denys-Drash Syndrome.

Introduction: Denys-Drash Syndrome (DDS) consists of a triad of pseudohermaphroditism, Wilms'tumor and nephropathy. This condition may manifest as a complete triad or in an incomplete form; with either one or a combination of the above features. The characteristic glomerular abnormality in DDS is diffuse mesangial sclerosis (DMS).Case report: We report two cases of DDS with focal membranoproliferative glomerulonephritis (MPGN). Both of our cases were males with ambiguous genitalia. They had a similar heterozygous germline mutation in exon 9 of WT1, c.1180C>T, p.R394W; a known mutation hotspot for DDS. Case 1 had nephropathy at the age of 4 years and Case 2 at 2.5 years with different rates of progression to end-stage renal failure. Conclusion: Our findings, in combination with other reports, illustrate the clinicopathological heterogeneity of DDS. There are no universal recommendations for optimal management of patients with DDS due to the inability to accurately predict affected individuals' progress.

Unusual Presentation of Denys-Drash Syndrome in a Girl with Undisclosed Consumption of Biotin

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.

Papers presented at the fall 2020 Pediatric Urologic Oncology Work Group of the Societies of Pediatric Urology meetingNeonatal Serum Electrolyte and Proteinuria Screening on 46,XY Ambiguous Genitalia Patients May Allow Early Diagnosis of Denys-Drash Syndrome: A Case Report.

A term infant with prenatally noted ambiguous genitalia and nonpalpable gonads presented with life-threatening hyponatremia, hypertension, acidosis, and anuric renal failure requiring peritoneal dialysis at age 3 months.Sequencing confirmed 46, XY Denys-Drash syndrome (DDS) due to heterozygous Wilms tumor-1 exon 8 mutation encoding p.His445Arg. Renal US identified bilateral multifocal renal masses at age 8 months. Bilateral retroperitoneal nephrectomies found bilateral nephroblastomatosis without Wilms' tumor avoiding chemotherapy, followed by bilateral laparoscopic orchiopexies. We suggest monthly screening of 46, XY DSD cases for DDS by evaluating for proteinuria and electrolyte disarray starting at diagnosis of DSD to prevent acute life-threatening renal failure presentation.

Detailed clinical manifestations at onset and prognosis of neonatal-onset Denys-Drash syndrome and congenital nephrotic syndrome of the Finnish type.

BACKGROUND: Neonatal-onset Denys-Drash syndrome (NODDS) is a distinctive clinical entity and has a poor renal and life outcome. Early diagnosis of NODDS is important for managing disorders of sexual development and determining assigned gender. Although patients with NODDS and congenital nephrotic syndrome of the Finnish type (CNF) present with nephrotic syndrome in neonatal life or infancy, the clinical course of NODDS and factors distinguishing these diseases at onset is unknown. METHODS: We performed a retrospective cohort study of patients with NODDS and CNF between 1997 and 2017. Patients with nephrotic syndrome and WT1 or NPHS1 mutations with neonatal onset (within 30 days) were eligible. RESULTS: We studied eight patients with NODDS and 15 with CNF. The median serum creatinine level at onset in the NODDS group was significantly higher (1.85 mg/dL) than that in the CNF group (0.15 mg/dL; P = 0.002). The median placental/fetal weight ratio in the NODDS and CNF group was 41.8% and 21.0%, respectively (P = 0.001). Kaplan-Meier analysis showed that the median number of days for progression to ESRD from onset in the NODDS and CNF groups was 6 and 910 days, respectively (P < 0.001). All patients in the NODDS group were alive at follow-up. Only one patient in the CNF group died of cardiac complications during follow-up. CONCLUSION: CNS, renal dysfunction at onset, and a relatively large placenta are prominent signs of NODDS. Prognosis for patients with NODDS is satisfactory if appropriate and active management is performed.

Testicular Preservation in 46 XY Denys-Drash Syndrome: A Report of Two Cases.

Denys Drash Syndrome (DDS) is a rare combination of genital and urinary anomalies that are mostly associated with malignancy. We report 2 patients who presented with genital ambiguity and were diagnosed as 46-XY DDS. During the discussion of the management plan, parents preferred to keep the gonads to preserve its endocrinal function for future sexual development. However, both patients developed primary hypogonadism at puberty and required testosterone supplementation. Persevering gonads in such patients had no endocrinal benefits but put the patients at risk of malignant transformation.

[Clinical and pathological features and mutational types of WT1 mutation-associated nephropathy].

Objective: To explore the clinical and pathological features and mutational types and their relations with WT1 mutation-associated nephropathy (WT1MAN). Methods: The clinical and pathological data and the results of WT1 mutation analysis of the cases from Nanfang Hospital of Southern Medical University, Sun Yat-sen Memorial Hospital and The First Affiliated Hospital of Sun Yat-sen University whom we recruited recently and reported during the last ten years were analyzed. Results: Totally, 20 cases (6 males and 14 females), included 5 newly diagnosed cases, were recruited. (1) Ten children were diagnosed with Denys-Drash syndrome (DDS): The median onset age of proteinuria was 1 year and 7 months. Diffuse mesangial sclerosis (DMS) were revealed in 3 cases, minimal lesions (MCD) in 4 cases, and focal segmental glomerulosclerosis (FSGS) in 1 case; renal pathology was not available in the other 2 cases. Glomerular basement membrane (GBM) thickening was observed in 2 cases. Calcineurin inhibitors (CNIs) were administered in 5 cases, complete remission of proteinuria was observed in 3 cases, partial remission in the other 2 cases. Genetic analysis revealed that six cases had WT1 missense mutation, 3 had nonsense mutation, and 1 had frameshift mutation. (2) Two cases were diagnosed with Frasier syndrome (FS): proteinuria was observed at 1 year and 1 month of age and 1 year and 9 months of age, respectively. FSGS with GBM layering were observed in both cases. They progressed to ESRD at 1 year and 6 months of age and 6 years and 6 months of age, respectively. CNI was tried in 1 case with partial proteinuria remission. Both patients were detected to have WT1 splice mutation. (3) Isolated nephropathy (IN) was observed in 8 cases: three had splice mutation, 5 had missense mutation. Of the 3 patients with splice mutation, one was found to have nephropathy and renal failure at the age of 5 months. The other two cases (1 was FSGS and another MCD), both had GBM layering. CNIs were tried on both of them, one got partial remission with normal renal function at the age of fourteen years, the other one had no response and entered ESRD at the age of 6 years and 9 months. Of the 5 cases with missense mutation, 3 had DMS, 2 of them entered ESRD within 6 months of age, another case had DMS entered ESRD at 9 years of age. One case with FSGS, was treated with CNIs and got complete remission. Conclusions: Slow progression (7/10) nephropathy was observed in DDS patients. Missense mutation (11/20) was the most common type of WT1 variants, followed by splice mutation (5/20) in this group of patients. Early onset nephropathy (4/5), rapid progression (4/5) and GBM layering (4/4) wereobserved in patients with splice mutation. CNI was effective in reducing or even eliminating proteinuria in WT1 MAN patients (8/9).

Role for first zinc finger of WT1 in DNA sequence specificity: Denys-Drash syndrome-associated WT1 mutant in ZF1 enhances affinity for a subset of WT1 binding sites.

Wilms tumor protein (WT1) is a Cys2-His2 zinc-finger transcription factor vital for embryonic development of the genitourinary system. The protein contains a C-terminal DNA binding domain with four tandem zinc-fingers (ZF1-4). An alternative splicing of Wt1 can add three additional amino acids-lysine (K), threonine (T) and serine (S)-between ZF3 and ZF4. In the -KTS isoform, ZF2-4 determine the sequence-specificity of DNA binding, whereas the function of ZF1 remains elusive. Three X-ray structures are described here for wild-type -KTS isoform ZF1-4 in complex with its cognate DNA sequence. We observed four unique ZF1 conformations. First, like ZF2-4, ZF1 can be positioned continuously in the DNA major groove forming a 'near-cognate' complex. Second, while ZF2-4 make base-specific interactions with one DNA molecule, ZF1 can interact with a second DNA molecule (or, presumably, two regions of the same DNA molecule). Third, ZF1 can intercalate at the joint of two tail-to-head DNA molecules. If such intercalation occurs on a continuous DNA molecule, it would kink the DNA at the ZF1 binding site. Fourth, two ZF1 units can dimerize. Furthermore, we examined a Denys-Drash syndrome-associated ZF1 mutation (methionine at position 342 is replaced by arginine). This mutation enhances WT1 affinity for a guanine base. X-ray crystallography of the mutant in complex with its preferred sequence revealed the interactions responsible for this affinity change. These results provide insight into the mechanisms of action of WT1, and clarify the fact that ZF1 plays a role in determining sequence specificity of this critical transcription factor.

Hemolytic uremic syndrome as the presenting manifestation of WT1 mutation and Denys-Drash syndrome: a case report.

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.

WT1 Haploinsufficiency Supports Milder Renal Manifestation in Two Patients with Denys-Drash Syndrome.

Denys-Drash syndrome (DDS) is characterized by nephropathy, 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.

Denys-Drash syndrome associated WT1 glutamine 369 mutants have altered sequence-preferences and altered responses to epigenetic modifications.

Mutations in human zinc-finger transcription factor WT1 result in abnormal development of the kidneys and genitalia and an array of pediatric problems including nephropathy, blastoma, gonadal dysgenesis and genital discordance. Several overlapping phenotypes are associated with WT1 mutations, including Wilms tumors, Denys-Drash syndrome (DDS), Frasier syndrome (FS) and WAGR syndrome (Wilms tumor, aniridia, genitourinary malformations, and mental retardation). These conditions vary in severity from individual to individual; they can be fatal in early childhood, or relatively benign into adulthood. DDS mutations cluster predominantly in zinc fingers (ZF) 2 and 3 at the C-terminus of WT1, which together with ZF4 determine the sequence-specificity of DNA binding. We examined three DDS associated mutations in ZF2 of human WT1 where the normal glutamine at position 369 is replaced by arginine (Q369R), lysine (Q369K) or histidine (Q369H). These mutations alter the sequence-specificity of ZF2, we find, changing its affinity for certain bases and certain epigenetic forms of cytosine. X-ray crystallography of the DNA binding domains of normal WT1, Q369R and Q369H in complex with preferred sequences revealed the molecular interactions responsible for these affinity changes. DDS is inherited in an autosomal dominant fashion, implying a gain of function by mutant WT1 proteins. This gain, we speculate, might derive from the ability of the mutant proteins to sequester WT1 into unproductive oligomers, or to erroneously bind to variant target sequences.

Clinical Aspects of WT1 and the Kidney.

For more than 30 years, WT1 mutations have been associated with complex developmental syndromes involving the kidney. Acting as a transcription factor, WT1 is expressed throughout the nephron and controls the reciprocal interactions and phenotypic changes required for normal renal development. In the adult, WT1 expression remains extremely high in the renal podocyte, and at a lower level in the parietal epithelial cells. Wt1-null mice are unable to form kidneys [1]. Unsurprisingly, WT1 mutations lead to significant abnormalities of the renal and genitourinary tract, causing a number of human diseases including syndromes such as Denys-Drash syndrome, Frasier syndrome, and WAGR syndrome. Recent methodological advances have improved the identification of WT1 mutations, highlighting its importance even in nonsyndromic renal disease, particularly in steroid-resistant nephrotic syndrome. This vast spectrum of WT1-related disease typifies the varied and complex activity of WT1 in development, disease, and tissue maintenance.

Refining the Diagnosis of Congenital Nephrotic Syndrome on Long-term Stored Tissue: c.1097G>A (p.(Arg366His)) WT1 Mutation Causing Denys Drash Syndrome.

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.

Malformation syndromes associated with disorders of sex development.

When embryological development of the internal and/or external genitalia is disrupted, the patient presents with a disorder of sex development (DSD) in the neonatal period or sometime later in life. Some of these patients have other, nongenital malformations, which makes their overall management more complex than if they just had a DSD. This Review summarises these malformation syndromes and discusses the recent research into their aetiology. The genetic causes of these malformation syndromes, when they are known, will also be described. Many specific genetic mutations are now known in malformation syndromes with a defect in hormonal function. By contrast, the genetic causes remain unknown in many nonhormonal morphological anomalies that affect the genitalia.