Genome-wide analysis associates familial colorectal cancer with increases in copy number variations and a rare structural variation at 12p12.3.

Authors:
Rongxi Yang, Bowang Chen, Katrin Pfütze, Stephan Buch, Verena Steinke, Elke Holinski-Feder, Sarah Stöcker, Witigo von Schönfels, Thomas Becker, Hans K Schackert, Brigitte Royer-Pokora, Matthias Kloor, Wolff H Schmiegel, Reinhard Büttner, Christoph Engel, Jesus Lascorz Puertolas, Asta Försti, Nelli Kunkel, Peter Bugert, Stefan Schreiber, Michael Krawczak, Clemens Schafmayer, Peter Propping, Jochen Hampe, Kari Hemminki, Barbara Burwinkel
Year of publication:
2014
Volume:
35
Issue:
2
Issn:
0143-3334
Journal title abbreviated:
CARCINOGENESIS
Journal title long:
Carcinogenesis
Impact factor:
4.874
Abstract: 
Colorectal cancer (CRC) is one of the most common cancer worldwide. However, a large number of genetic risk factors involved in CRC have not been understood. Copy number variations (CNVs) might partly contribute to the ''missing heritability'' of CRC. An increased overall burden of CNV has been identified in several complex diseases, whereas the association between the overall CNV burden and CRC risk is largely unknown. We performed a genome-wide investigation of CNVs on genomic DNA from 384 familial CRC cases and 1285 healthy controls by the Affymetrix 6.0 array. An increase of overall CNV burden was observed in familial CRC patients compared with healthy controls, especially for CNVs larger than 50kb (case/control ratio = 1.66, P = 0.025). In addition, we discovered for the first time a novel structural variation at 12p12.3 and determined the breakpoints by strategic PCR and sequencing. This 12p12.3 structural variation was found in four of 2862 CRC cases but not in 6243 healthy controls (P = 0.0098). RERGL gene (RERG/RAS-like), the only gene influenced by the 12p12.3 structural variation, sharing most of the conserved regions with its close family member RERG tumor suppressor gene (RAS-like, estrogen-regulated, growth inhibitor), might be a novel CRC-related gene. In conclusion, this is the first study to reveal the contribution of the overall burden of CNVs to familial CRC risk and identify a novel rare structural variation at 12p12.3 containing RERGL gene to be associated with CRC.