Increased Sensitivity for Detection of Mutations in Exon 15 of the APCGene in Patients with Familial Adenomatous Polyposis

Overview

Background.
Protein Truncation Test (PTT) was used to detect mutations in exon 15 of the APC gene in patientswith Familial Adenomatous Polyposis. This method is limited by its ability to detect polypetide chains up to a certainminimum length. The aim of this study was to increase the sensitivity of detection of mutations in this region byusing the technique of Denaturing Gradient Gel Electrophoresis (DGGE).Methods and Results. Study were performed on 122 patients without detected mutations in the APC gene. Thepatients were divided into two independent groups 15A and 15A+15B (with 51 and 71 patients respectively). Allthe patients were tested with the DGGE and the positive findings were confirmed with sequencing. No mutation wasdetected in the group 15A (0 %). In group 15A+15B one (1,4 %) polymorphism and four (5,63 %) patients withnonsense mutations were detected.Conclusions. DGGE is an effective method for detecting mutations in the first part of exon 15 of APC gene. It allowsdetecting any change in DNA strand. DGGE complements PTT in scanning of the whole exon 15 of APC gene.

Key words:
familial adenomatous polyposis, adenomatous polyposis coli, APC gene, denaturing gradient gelelectrophoresis.