Background/Purpose: Wilms' tumor is the most common renal malignancy of childhood. Loss of heterozygosity (LOH) at 16q is seen in about 17% of cases and has been associated with a poor prognosis. To more precisely define the pattern of 16q deletion exhibited by Wilms' tumor, the authors performed a detailed LOH analysis of 96 specimens using polymorphic microsatellite repeat markers. The authors also evaluated the neoplasms for the presence of microsatellite instability (MSI). Methods: A total of 96 DNA samples were studied using polymerase chain reaction-based LOH analyses amplifying polymorphic microsatellite repeat markers. Screening for MSI using 2 additional genetic markers also was carried out. Results: The authors found 16q LOH in 14 of the specimens evaluated. Comprehensive analysis of these LOH-positive specimens showed a region of loss spanning 16p 11.2-q22.1 and a separate distal region of LOH at 16q23.2-24.2. The distal region of deletion is very small, estimated to be approximately 2.4 megabases. In addition to the observed LOH, 2 specimens were found to consistently exhibit MSI, which has not been reported previously in Wilms' tumor. Conclusions: The smallest consensus region of deletion in our analysis of Wilms' tumor 16q LOH measures 2.4 megabases at 16q23.2-q24.2. Additionally, MSI was present in a subset of tumor specimens suggesting that defects in DNA mismatch repair may contribute to the pathogenesis of Wilms' tumor. Copyright (C) 2000 by W.B. Saunders Company.
- Chromosome 16
- Loss of heterozygosity (LOH)
- Microsatellite instability (MSI)
- Wilms' tumor
ASJC Scopus subject areas
- Pediatrics, Perinatology, and Child Health