Abstract for presentation at 11th International Congress of Human Genetics

Screening for Sub-microscopic Chromosomal Rearrangements in Wilms Tumor using Whole Genome Microarrays

  • Dr Shahrad Rassekh, British Columbia's Children's Hospital, Canada
  • Ms Chansonette Harvard, University of British Columbia, Canada
  • Dr David Dix, British Columbia's Children's Hospital, Canada
  • Dr Suzanne Chan, University of British Columbia, Canada
  • Dr Gareth Jevon, British Colubia's Children's Hospital, Canada
  • Evica Rajcan-Separovic, University of British Columbia, Canada

    • Purpose: Wilms tumor is a common childhood solid malignancy involving the kidney. The pathogenesis of Wilms tumor is largely unknown, and up to 50% of Wilms tumors have normal cytogenetics using conventional methods. This suggests that in a significant number of cases genetic changes may occur at the sub-microscopic level and remain undetected during microscopic analysis. Array comparative genomic hybridization (array CGH) has been successful in detecting small deletions and duplications in many solid malignancies. The purpose of this study is to utilize array CGH in order to detect novel chromosomal abnormalities in Wilms tumor, in order to learn more about its pathogenesis.
    Methods: Conventional cytogenetics and chromosomal CGH had been performed on 14 samples of Wilms tumors, including10 tumors with normal cytogenetics and 4 tumors with t(1;16) which is a well reported translocation seen in Wilms. Array CGH was then performed on these 14 tumors. Duplications or deletions found are confirmed by FISH.
    Results: Array CGH was run on all 14 samples of Wilms tumor and areas of microdeletions on 2q, 4q, 7p, 8p, 11q and 16q were found. Microduplications seen included areas of 7q, 10q, and 17q. We confirmed the microdeletions of 11q and 7p, while the confirmation of other changes by FISH is in progress.
    Conclusions: Array CGH provides a very valuable method of analyzing the cytogenetics of Wilms tumor, and may identify previously unrecognized common sub-microscopic chromosomal changes. Using array CGH, we have thus far identified several areas of submicorscopic change in samples previously thought to have normal cytogenetics. The confirmed deletions of 11q and 7p are in areas of interest and we are pursuing whether these micro-deletions are seen in other cases of Wilms tumors.

    Conference Organiser - ICMS Pty Ltd