Recurrent Coding Sequence Variation Explains Only A Small Fraction of the Genetic Architecture of Colorectal Cancer

Sci Rep. 2015 Nov 10:5:16286. doi: 10.1038/srep16286.

Abstract

Whilst common genetic variation in many non-coding genomic regulatory regions are known to impart risk of colorectal cancer (CRC), much of the heritability of CRC remains unexplained. To examine the role of recurrent coding sequence variation in CRC aetiology, we genotyped 12,638 CRCs cases and 29,045 controls from six European populations. Single-variant analysis identified a coding variant (rs3184504) in SH2B3 (12q24) associated with CRC risk (OR = 1.08, P = 3.9 × 10(-7)), and novel damaging coding variants in 3 genes previously tagged by GWAS efforts; rs16888728 (8q24) in UTP23 (OR = 1.15, P = 1.4 × 10(-7)); rs6580742 and rs12303082 (12q13) in FAM186A (OR = 1.11, P = 1.2 × 10(-7) and OR = 1.09, P = 7.4 × 10(-8)); rs1129406 (12q13) in ATF1 (OR = 1.11, P = 8.3 × 10(-9)), all reaching exome-wide significance levels. Gene based tests identified associations between CRC and PCDHGA genes (P < 2.90 × 10(-6)). We found an excess of rare, damaging variants in base-excision (P = 2.4 × 10(-4)) and DNA mismatch repair genes (P = 6.1 × 10(-4)) consistent with a recessive mode of inheritance. This study comprehensively explores the contribution of coding sequence variation to CRC risk, identifying associations with coding variation in 4 genes and PCDHG gene cluster and several candidate recessive alleles. However, these findings suggest that recurrent, low-frequency coding variants account for a minority of the unexplained heritability of CRC.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Activating Transcription Factor 1 / genetics
  • Adaptor Proteins, Signal Transducing
  • Alleles
  • Cadherins / genetics
  • Case-Control Studies
  • Colorectal Neoplasms / genetics*
  • Colorectal Neoplasms / pathology
  • Gene Frequency
  • Genetic Variation*
  • Genome-Wide Association Study
  • Genotype
  • Humans
  • Intracellular Signaling Peptides and Proteins
  • Linkage Disequilibrium
  • Odds Ratio
  • Polymorphism, Single Nucleotide
  • Proteins / genetics
  • White People / genetics

Substances

  • ATF1 protein, human
  • Activating Transcription Factor 1
  • Adaptor Proteins, Signal Transducing
  • Cadherins
  • Intracellular Signaling Peptides and Proteins
  • Proteins
  • SH2B3 protein, human