Table 4

Relationship between mutation site and age at diagnosis achieved after bowel symptoms had developed in 230 patients with known mutations and in 174 patients with unknown mutations

Group APC mutation Predicted phenotype No patients Age at diagnosis
(y) (mean (SD))
1Codon 139–156AAPC1152.2 (16.5)
Codon 332 (exon 9)
Codon 1596–2557
2Codon 170–1578 (except 1309; 332)Typical FAP16930.4 (10.0)
3Codon 1309Severe FAP4519.8 (11.5)
4Large deletions?527.8 (5.9)
5No mutation identified?17437.7 (14.4)
6All patients40432.9 (13.9)
  • Statistical comparisons (two tailedt test for unequal samples): 1v 2, p=0.0028; 1v 3, p<0.0001; 1v 5, p=0.0159; 2v 5, p<0.0001; 3v 5, p<0.0001; 2v 3, p<0.0001.

  • FAP, familial adenomatous polyposis; AAPC, attenuated adenomatous polyposis coli.