Published online Feb 28, 2018. doi: 10.3748/wjg.v24.i8.949
Peer-review started: December 14, 2017
First decision: January 5, 2018
Revised: January 11, 2018
Accepted: January 20, 2018
Article in press: January 20, 2018
Published online: February 28, 2018
Synovial sarcoma (SS) is genetically characterized by chromosomal translocation, which generates SYT-SSX fusion transcripts. Although SS can occur in any body part, primary gastric SS is substantially rare. Here we describe a detection of the fusion gene sequence of gastric SS in plasma cell-free DNA (cfDNA). A gastric submucosal tumor was detected in the stomach of a 27-year-old woman and diagnosed as SS. Candidate intronic primers were designed to detect the intronic fusion breakpoint and this fusion sequence was confirmed in intron 10 of SYT and intron 5 of SSX2 by genomic polymerase chain reaction (PCR) and direct sequencing. A locked nucleic acid (LNA) probe specific to the fusion sequence was designed for detecting the fusion sequence in plasma and the fusion sequence was detected in preoperative plasma cfDNA, while not detected in postoperative plasma cfDNA. This technique will be useful for monitoring translocation-derived diseases such as SS.
Core tip: Synovial sarcoma (SS) is genetically characterized by SYT-SSX fusion transcripts and detection of the fusion gene is necessary for a definitive diagnosis. This study demonstrated the detection of fusion sequence using cfDNA sample. A small gastric SS was detected in the stomach of a 27-year-old woman. Candidate intronic primers were designed and the intronic breakpoint was confirmed by PCR and direct sequencing in frozen tumor sample. A probe specific for fusion sequence was designed and the sequence was detected in preoperative cfDNA and frozen tumor sample. This technique will be useful for monitoring translocation-derived diseases such as SS.