Genetic and Epigenetic Drivers of Wilms Tumor Predisposition in Russian Pediatric Patients: A Multicenter Study.

Wilms tumor (WT), the most common kidney neoplasm in children, is closely associated with hereditary factors. This study included 134 WT patients (62 males, median age of 7 years, age at diagnosis of 24.9 months) with unilateral (n = 90, 67%) or bilateral WT (n = 44, 33%). Genetic testing was performed using targeted sequencing of 415 genes and multiplex ligation-dependent probe amplification (MLPA). Twenty-five mutations in eight genes were found in 17% (n = 23) of patients: WT1 (n = 10), TRIM28 (n = 4), REST (n = 3), CHEK2 (n = 3), BRCA2 (n = 2), NF1 (n = 1), RAD50 (n = 1), and CDC73 (n = 1). Large deletions of the 11p13 region were revealed in 6% (n = 5) of patients. The 11p15 locus methylation was studied in blood, tumor, and healthy kidney tissue of nine patients suspected of Beckwith-Wiedemann syndrome (BWS) using methylation-sensitive MLPA (MS-MLPA). BWS was diagnosed in 3% (n = 4) of cases (one patient had mosaic disease). Thus, genetic and epigenetic aberrations were identified in 32 WT patients (24%). These patients had a higher frequency of bilateral WT and a higher rate of abnormalities compared to patients without aberrations (56% vs. 25%, p = 0.002; and 86% vs. 25%, p < 0.0001, respectively). The detection of WT hereditary predisposing factors is crucial for treatment strategies and long-term patient surveillance.