Analysis of the pooled APC mutation data by Chi-square test of association shows an odds ratio of 3.7 (P < .005) for all brain tumor subtypes and 13.1 (P < .001) for medulloblastoma in patients harboring segment 2 APC mutation (codons 679-1224) compared to nonsegment 2 mutation.
The association between brain tumors and multiple colorectal adenomas can result from two distinct types of germ-line defects: mutation of the APC gene or mutation of a mismatch-repair gene.