The Drash syndrome: male pseudohermaphroditism, nephritis, and Wilms tumor

Insights into the physiological role of WT1 from studies of genetically modified mice

Discenza, Maria Teresa, and Jerry Pelletier. Insights into the physiological role of WT1 from studies of genetically modified mice. Physiol Genomics 16: 287-300, 2004; 10.1152/physiolgenomics.00164.2003.—The identification of WT1 gene mutations in children with WAGR and Denys-Drash syndromes pointed toward a role for WT1 in genitourinary system development. Biochemical analysis of the different WT1 protein isoforms showed that WT1 is a transcription factor and also has the ability to bind RNA. Analysis of WT1 complexes identified several target genes and protein partners capable of interacting with WT1. Some of these studies placed WT1, its downstream targets, and protein partners in a transcriptional regulatory network that controls urogenital system development. We review herein studies on WT1 knockout and transgenic models that have been instrumental in defining a physiological role for WT1 in normal and abnormal urogenital development.

Renal neoplasms of childhood

Wilms' tumor is the most common childhood renal tumor. This article describes the epidemiology, histopathologic features, and clinical manifestations of Wilms' tumor along with the spectrum of imaging findings using different modalities. The distinguishing features of other renal tumors encountered in children, such as clear cell sarcoma, rhabdoid tumor, congenital mesoblastic nephroma, multilocular cystic renal tumor, renal cell carcinoma, and angiomyolipoma are also reviewed.

The Denys-Drash syndrome

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Persistence of müllerian derivatives, lymphangiectasis, hepatic failure, postaxial polydactyly, renal and craniofacial anomalies

We describe 3 unrelated newborn males with a previously unreported constellation of congenital anomalies. All 3 died neonatally of hepatic failure. Clinically, they presented with a pattern of malformations characterized by prenatal linear growth deficiency, hypertrophied alveolar ridges, redundant nuchal skin, and postaxial polydactyly. All 3 cases had male external genitalia with cryptorchidism, and 2 of them, a small penis. Necropsies showed similar internal anomalies, consisting of müllerian duct remnants, lymphangiectasis, and renal anomalies. The karyotypes were normal (46, XY) in skin fibroblasts (Case 1) and in peripheral blood lymphocytes (Case 3). Although this pattern of congenital anomalies must be differentiated from several other lethal syndromes, to our knowledge, no similar cases have been described previously. Cause of this syndrome is unknown. Because Case 2 had a previous brother with similar anomalies, we suspect that this new entity probably is an autosomal recessive or X-linked trait.

Nephrotic syndrome in the 1st year of life

Among the various primary conditions which may be associated with a nephrotic syndrome at birth or within the 1st year of life, the best known is the congenital nephrotic syndrome of finnish type (CNF) characterized by irregular pseudocystic dilatation of proximal tubules. This disease, very frequent in Finland, is often familial with an autosomal recessive mode of inheritance. Patients are steroid resistant, but the cause of death is usually not uraemia but infection or severe diarrhoea with electrolyte imbalance. The second condition is idiopathic nephrosis including minimal change disease, diffuse mesangial proliferation and focal segmental glomerular sclerosis. As opposed to CNF, infants with "early onset nephrosis" may respond to steroid therapy as older children do and may even recover. However, there are no histopathological criteria which allow the certain differentiation of idiopathic nephrosis from CNF. The third condition is diffuse mesangial sclerosis (DMS), a clinicopathological entity which can occur as an isolated finding or be associated with male pseudohermaphroditism and/or Wilms' tumour (Drash syndrome). From a morphological point of view, DMS is easy to differentiate from CNF because of the characteristic pattern of involvement of the glomeruli. From a clinical point of view, the nephropathy, almost always characterized by a nephrotic syndrome, has two distinct features: it is most often diagnosed in the first 2 years of life and it progresses rapidly to end-stage renal failure, which usually occurs before the age of 3 years. The clinical findings in 36 patients with DMS are presented. The nephropathy was isolated in 22 infants and associated with male pseudohermaphroditism and/or Wilms' tumour in 14.(ABSTRACT TRUNCATED AT 250 WORDS)

Nephrogenic rests in Wilms tumor patients with the Drash syndrome

The histological specimens from 12 patients with the Drash syndrome were identified from the National Wilms Tumor Study Group and reviewed for the presence of nephrogenic rests. Of 7 patients with the complete Drash syndrome 6 were evaluable for nephrogenic rests, including 5 (83%) who demonstrated intralobar nephrogenic rests. Of 5 (80%) partial Drash syndrome cases 4 (80%) were also intralobar nephrogenic rest positive. Neither group had perilobar nephrogenic rests identified. In a control population of Wilms tumor patients without the Drash syndrome only 39 of 274 (14%) with unilateral tumor had intralobar nephrogenic rests identified, whereas 26 of 92 (28%) bilateral cases had intralobar nephrogenic rests. There was a significantly higher rate of intralobar nephrogenic rests in complete and partial Drash syndrome cases than in the general Wilms tumor population (p less than 0.001). Wilms tumor patients with intralobar nephrogenic rests and the Drash syndrome present at a younger age and have a higher rate of bilaterality than rest negative Wilms tumor patients. The strong association of intralobar nephrogenic rests in the Drash syndrome approaches that found in the aniridia complex. However, in other syndromes associated with Wilms tumor, such as the Beckwith-Wiedemann syndrome and hemihypertrophy, there is a high prevalence of perilobar nephrogenic rests. In view of the high incidence of intralobar nephrogenic rests in complete and partial Drash syndrome patients, it is probable that events leading to Wilms tumor in patients with the Drash syndrome occur at an early stage in nephrogenesis.

T-cell lymphoma and mature nephroblastoma after synchronous bilateral Wilms' tumor

A 15-year-old boy had lymphoblastic lymphoma of the left tonsil after being treated for bilateral Wilms' tumor (BWT) at 7 months of age. In addition, a fully differentiated Wilms' tumor was diagnosed in the remaining, partially nephrectomized left kidney. Development of second malignancies in patients with a history of BWT, as compared with those with unilateral Wilms' tumor, is discussed. A possible explanation for the concurrently diagnosed, fully differentiated Wilms' tumor in the remaining left kidney is suggested.

The association of Wilms' tumor with nephrologic disease

Three cases of nephrologic disease characterized clinically by nephrotic syndrome and histologically with mesangial sclerosis associated with Wilms' tumor are documented. Two children were born with ambiguous genitalia and an XY chromosome constitution. A third patient had a 46,XY karyotype and developed a Wilms' tumor but had a normal female phonotype. The evaluation and current management of this syndrome are discussed.

A report of 4 patients with the Drash syndrome and a review of the literature

Four patients with the Drash syndrome, represented by the triad of male pseudohermaphroditism, progressive renal insufficiency and Wilms tumor are discussed. This syndrome, which some have suggested should be expanded to include patients with nephropathy, Wilms tumor and any abnormality of gonadal differentiation, appears early in life. The first sign usually is genital ambiguity. However, proteinuria, hematuria and hypertension eventually require renal biopsy, which may reveal a variety of glomerular and interstitial changes. The nephropathy progresses rapidly, is unresponsive to steroids and eventually requires dialysis. Wilms tumor may appear as a mass on ultrasound or it may not be recognized until nephrectomy or even autopsy. Young children with gonadal dysgenesis and nephropathy are at high risk for nephroblastoma and gonadal tumors and, therefore, prophylactic nephrectomy and gonadectomy should be considered early in the course of this disease.

The association of Wilms' tumor, male pseudohermaphroditism and diffuse glomerular disease (Drash syndrome): report of eight cases with clinical and morphologic findings and review of the literature

In 8 children (6 males) at least 2 of 3 disorders were found--male pseudohermaphroditism (MPH), Wilm's tumor, and glomerular disease. MPH was present in the 6 males; they had abdominal cryptorchidism (6/6), ambiguous genitalia (6/6), negative sex chromatin (5/5), and 46XY karyotype (2/2). The gonads examined microscopically in 3 patients were dysgenetic testes. The renal tumor present in 7 was nephroblastoma (NB) of the classical type without anaplasia or nephroblastomatosis, bilateral in 1, and unilateral but multinodular in 2. Five underwent nephrectomy for a renal mass, and in 2 NB was found at open biopsy or at autopsy. The mean age at diagnosis was 10 months. Glomerular disease in 6 patients began with onset of the nephrotic syndrome between 20 days and 39 months of age; it was resistant to steroid therapy and led to death from renal failure. Microscopically the glomerular process was a diffuse mesangial sclerosis (DMS). The 2 children with NB and MPH, but without DMS are healthy 2 1/2 and 9 years postnephrectomy. Neither familial incidence nor parental consanguinity was found. This syndrome has complete and partial forms, and its early recognition is important both for patient management and for assessment of prognosis.

Complete and incomplete Drash syndrome: a clinicopathologic study of five cases of a dysontogenetic-neoplastic complex

Drash syndrome is a complex disorder characterized by abnormal renal function, abnormal sexual differentiation with predisposition to developing gonadal neoplasms, and nephroblastoma. The authors report five cases with various manifestations of this syndrome. Dysgenetic gonads and abnormal sexual differentiation were present in all patients; two had unilateral and two bilateral gonadoblastomas; in addition, one of the latter had a juvenile granulosa cell tumor. Renal failure was present in all patients. One patient had bilateral Wilms' tumor, and one patient had a metanephric hamartoma. Each element of the triad in this syndrome is analyzed with regard to possible pathogenetic mechanisms and current models of carcinogenesis. Cases with complete forms of the syndrome reported in the literature are reviewed. Patients with incomplete forms of the syndrome must be followed carefully because other elements of this complex may become manifest.

Pseudohermaphroditism, glomerulopathy, and Wilms tumor (Drash syndrome): frequency in end-stage renal failure

The sporadic concurrence of male pseudohermaphroditism and chronic glomerulopathy is associated with an extremely high risk of Wilms tumor. We report our experience with an infant who developed this triad (Drash syndrome) and review the 21 patients described in the literature, to emphasize the importance of early diagnosis and to suggest guidelines for management. The dysgenetic gonads are always intra-abdominal and carry a 20% to 30% risk for malignancy. The external genitalia are frequently ambiguous (77%); some children are phenotypically normal females. The glomerulopathy typically leads to end-stage renal failure in infancy; the subsequent death rate has, to date, been 68%. The clinical presentation of renal disease is variable and includes congenital nephrotic syndrome (14%) and infantile nephrotic syndrome (41%); 27% of patients develop proteinuria and renal insufficiency between the ages of 1 and 3 years. The high risk of Wilms tumor (55% in this review) mandates regular tumor surveillance, and prophylactic bilateral nephrectomy and gonadectomy once irreversible renal failure develops.

External genital abnormalities associated with Wilms tumor

The records of 170 patients with unilateral and 18 patients with bilateral Wilms tumor and 6 patients with congenital mesoblastic nephroma were reviewed for abnormalities of the external genitalia. There were 4 patients with cryptorchism, 1 with hypospadias, 1 with mixed gonadal dysgenesis, and 3 with male pseudohermaphroditism. Of the group, these 9 patients had earlier symptoms; 6 of them were under two years old. Five patients (27.7%) with bilateral Wilms tumors had external genital anomalies in contrast to only 4 (2.3%) of those with unilateral tumors. One of the 9 children with genital anomalies had unilateral congenital mesoblastic nephroma; the others had Wilms tumor. In all cases the histologic subtypes were unusual. These observations substantiate the previously reported association between external genital abnormalities and Wilms tumor and also represent a somewhat higher than expected incidence. The children with this association are remarkable for the high frequency of a particular histologic type of tumor and for the high incidence of bilaterality. The high incidence of Wilms tumors in the male pseudohermaphrodite population presented suggests that such patients should be monitored for development of renal tumors.