Polyposis Caused by Low APC MosaicismAriel A Benson4, Brian H Shirts2, Angela Jacobson2, Colin C Pritchard2, Tom Walsh3, Harold Jacob4 and Yael Goldberg1*
- *Corresponding Author:
- Yael Goldberg, MD
Sharett Institute of Oncology
Hadassah-Hebrew University Medical Center
PO Box 12000 Jerusalem, 91120 Israel
E-mail: [email protected]
Received date: December 01, 2015; Accepted date:December 23, 2015; Published date: January 05, 2016
Citation: Benson AA, Shirts BH, Jacobson A, Pritchard CC, Walsh T, et al. (2016) Polyposis Caused by Low APC Mosaicism. J Genet Syndr Gene Ther 7:281. doi:10.4172/2157-7412.1000281
Copyright: © 2016 Benson AA, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Purpose: To present a patient with familial adenomatous polyposis (FAP) caused by a low level of somatic mosaicism. Case description: A twenty-one year old female presented with rectal bleeding and abdominal pain. She underwent a colonoscopy and esophagogastroduodenoscopy which revealed extensive polyposis. There was no family history of polyps or early onset colon cancer in her family. Methodology: Next-generation sequencing (NGS) analysis was performed using the ColoSeqTM panel on DNA extracted from both peripheral blood lymphocytes and colonic polyps. RESULTS: Molecular analysis detected the p.E1408X deleterious mutation in the APC gene in in 12 of 276 (4%) reads of the DNA in the peripheral blood leukocytes and in 30% of the DNA from colonic polyps. Conclusion: We report that low level of 4% APC mosaicism led to florid polyposis. Our report highlights the power of deep next-generation sequencing to identify mosaic mutations that are missed by traditional approaches. Though somatic APC mosaicism has previously been reported to cause polyposis syndrome in a few cases, it has been underestimated as a cause of polyposis coli. This case should reinforce the need to search for mosaicism in all patients with a personal history of polyposis and no family history.