Genotype-phenotype correlation of WT1 mutation-related nephropathy in Chinese children

WT1 Gene Pathogenic Variants: Clinical Challenges and Treatment Strategies in Pediatric Nephrology-One Center Practice

Pathogenic variants in the Wilms' tumor suppressor gene 1 (WT1 gene) can lead to serious disorders within the kidney and urogenital system, including chronic kidney disease. There is still much uncertainty regarding the optimal management of diseases caused by WT1 dysfunction, posing a challenge for physicians caring for these patients. The aim of our study is to present experiences related to the course and treatment of patients with confirmed WT1 pathogenic variants. Data from seven patients (five girls, two boys), who were at the age of 4.8 ± 5.1 years (0.3-14 years) at their first admission and were treated between 1997-2022, were analyzed. The analysis included each patient's age at the day of diagnosis, anthropometric measurements, comorbidities, and laboratory and genetic test results, as well as their treatment, oncological procedures, and performed surgeries. Wilms' tumor was the first manifestation of the disease in three patients. Arterial hypertension was diagnosed in three patients, and anemia in four. Treatment of patients with nephrotic syndrome included glucocorticosteroid therapy (GCS), calcineurin inhibitors (CNIs), and mycophenolate mofetil (MMF). Nephrectomy was performed in five children, while kidney transplantation was carried out in two patients. An interdisciplinary approach to WT1 gene pathogenic variants, including early diagnosis, individualization, regular monitoring of treatment, and oncological vigilance, is crucial for improving prognosis and ensuring proper care for patients with nephrological manifestations of WT1 gene region disorders. Furthermore, for a comprehensive understanding of the scope of this disease and the development of effective therapy methods, continued research on the clinical manifestations of WT1 pathogenic variants is essential.

Genotype-Phenotype Correlations in Denys-Drash Syndrome in Children

Introduction

Denys-Drash syndrome (DDS) is a rare disease typically associated with a triad of early onset nephrotic syndromes (NS), susceptibility to Wilms tumor (WT), and genitourinary structural defects. DDS is caused by Wilms' tumor suppression gene (WT1) variants, with the most frequent variants in exons 8 and 9. This study aimed to evaluate the long-term clinical outcomes and genotype-to-phenotype correlations in a large, multicenter cohort of children with typical DDS.

Methods

We conducted a national retrospective study of all children diagnosed with a pathogenic variant in WT1 exons 8 or 9 in France between 2000 and 2022.

Results

Fifty-eight children with DDS and variants in exons 8 (n = 23) and 9 (n = 35) of the WT1 gene were identified. Half of the children presented with NS (57% congenital, median age at presentation 0.3 years [interquartile range, IQR: 0.0-0.6]). Twenty-nine percent of children developed WT at a median age of 1.2 (0.5-2.2) years. Children with a variant in exon 8 developed NS much earlier than those with a variant in exon 9 (P = 0.0048), regardless of the type of genetic variation, leading to earlyier kidney failure (KF) (0.3 vs.1.4 years respectively; P = 0.0001) and higher mortality (35% vs 9%, P = 0.02). More than 90% of the truncating variants were located in exon 9 and were significantly associated with the occurrence of WT compared with the DNA-binding-site variants (P < 0.0015).

Conclusion

In our cohort, children's DDS clinical trajectory was associated with exon localization. In the era of genomic newborn screening, depicting genetic risk is of utmost importance for personalized patient care.