Objective: To determine the region where the tumor susceptible genes located, and to study chromosome instability, deletion and rearrangement of genes in Peutz-Jeghers Syndrome.
Methods: The method of induction was used to detect chromosome fragile sites of patients, Who were contrasted to familiar members and healthy individuals. DNA was extracted from leukocyte, polypus and tumor tissues, fresh or embedded in paraffin. The highly frequent abnormality of chromosome 3p14 region was studied with PCR, PCR-SSCP, microsatellite analysis, and DNA sequencing.
Results: The highest frequency of fragile site was in chromosome 3p14-3p24 region. The aberration frequency of D3S3340 is 21.4%, and that of D3S30 is 14.3%. Microsatellite analysis demonstrated LOH, of which the frequency is 42.9%; in addition, APC, k-ras mutation also occurred. The loss of guanylic acid was found in D3S1766.
Conclusion: PJS has high chromosome instability, with deletion, mutation and arrangement of genes in 3p14 region, suggesting that cancer susceptible genes would be harbed in 3p14 cloning.