- 1-Weak association between the TGFBR 1 * 6 A variant and colorectal cancer : a family-based association study on non-syndromic family members from Australia and Spain

Background Genome-wide linkage studies have identified the 9q22 chromosomal region as linked with colorectal cancer (CRC) predisposition. A candidate gene in this region is transforming growth factor β receptor 1 (TGFBR1). Investigation of TGFBR1 has focused on the common genetic variant rs11466445, a short exonic deletion of nine base pairs which results in truncation of a stretch of nine alanine residues to six alanine residues in the gene product. While the six alanine (*6A) allele has been reported to be associated with increased risk of CRC in some population based study groups this association remains the subject of robust debate. To date, reports have been limited to population-based case-control association studies, or case-control studies of CRC families selecting one affected individual per family. No stu dy has yet taken advantage of all the genetic information provided by multiplex CRC famil ies. Methods We have tested for an association between rs11466445 and risk of CRC using several family-based statistical tests in a new study group comprising member s of non-