Is TGFBR1*6A a susceptibility allele for nonsyndromic familial colorectal neoplasia?
Our analysis definitely excludes the possibility of the TGFBR1*6A allele increasing the risk of colorectal neoplasia in our sample population. A recent study validating linkage of colorectal cancer to chromosome 9q also excluded the TGFBR1*6A allele as a disease-causing variant in that sample. We conclude that there remains an unidentified susceptibility locus in the region 9q22.2-31.2.