Table 1

APC germline mutations in 680 index patients grouped according to number of colorectal adenomas and family history

Subgroup according to No polyps and family history No index patients No APC germline mutations detected Detection rate of germline mutations (%)
>100 adenomas 268 156 58.2
 Familial1459766.9
 De novo1-150 312683.9
 No information923335.9
<100 adenomas 101 32 31.7
 Familial441738.7
 De novo10440.0
 No information471123.4
No of adenomas unknown 311 139 44.7
 Familial1689958.9
 De novo121083.3
 No information1313022.9
Total 680 327 48.1
  • 1-150 Both parents of patients classified as “de novo” had either negative colonoscopies at age >50 years or were still healthy at an advanced age.