A 2-year-old child has an abdominal mass discovered by the parents during bathing. It does not cross the midline, is firm and smooth. Urinalysis shows microscopic hematuria. CT abdomen shows a heterogeneous intrarenal mass with claw sign. Which tumor suppressor gene on chromosome 11 is most commonly mutated in sporadic cases of this tumor?
- A RB1 (retinoblastoma gene) on chromosome 13q14
- B p53 on chromosome 17p13
- C WT1 (Wilms tumor 1) on chromosome 11p13 ✓
- D NF1 (neurofibromatosis type 1) on chromosome 17q11
Explanation
Wilms tumor (nephroblastoma) is the most common renal malignancy in children. The WT1 tumor suppressor gene on chromosome 11p13 is mutated in approximately 10–15% of sporadic cases and in 100% of Denys-Drash syndrome cases (WT1 mutation + diffuse mesangial sclerosis + male pseudohermaphroditism). WAGR syndrome (Wilms tumor, Aniridia, Genitourinary anomalies, Range of developmental delays) involves deletion of 11p13 affecting both WT1 and PAX6. WT2 at 11p15 (Beckwith-Wiedemann) is a second locus. The 'claw sign' on CT (remaining renal tissue forming a claw around the mass) distinguishes intrarenal Wilms from neuroblastoma which displaces but does not arise from the kidney.
Reference: Ghai Essential Pediatrics, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.