Calculations using the algorithms of Wijnen et al1 to determine the probabilities of finding a germline MLH1 or MSH2 mutation in 10 mutation carrier probands previously ascertained by Aaltonen et al6
| Patient | Mean age of diagnosis of CRC in the family | Fulfilment of the Amsterdam criteria | Endometrial cancer in the family | No of patients with CRC | No of patients with endometrial cancer | No of family members with verified cancer status | p1 | p2 |
|---|---|---|---|---|---|---|---|---|
| (A) Limited pedigrees (proband and the first degree relatives) | ||||||||
| c35 | 49 | No | No | 2 | 0 | 6 | 3 | 8 |
| c54 | 36 | No | No | 1 | 0 | 4 | 10 | 17 |
| c64 | 53 | No | No | 2 | 0 | 5 | 2 | 6 |
| c125 | 52 | No | No | 2 | 0 | 9 | 2 | 6 |
| c145 | 42 | Yes | Yes | 3 | 1 | 12 | 78 | 31 |
| c219 | 50 | No | Yes | 1 | 1 | 7 | 13 | 11 |
| c340 | 61 | No | Yes | 3 | 2 | 7 | 5 | 14 |
| c430 | 38 | No | No | 2 | 0 | 4 | 8 | 19 |
| c558 | 57 | No | Yes | 4 | 2 | 8 | 7 | 24 |
| c564 | 45 | No | Yes | 2 | 1 | 7 | 19 | 20 |
| (B) Extended pedigrees | ||||||||
| c35 | 47 | Yes | No | 4 | 0 | 24 | 30 | 15 |
| c54 | 35 | No | No | 1 | 0 | 13 | 11 | 19 |
| c64 | 47 | Yes | No | 4 | 0 | 24 | 10 | 11 |
| c125 | 48 | Yes | No | 4 | 0 | 14 | 28 | 14 |
| c145 | 56 | Yes | Yes | 13 | 3 | 85 | 48 | 89 |
| c219 | 52 | No | Yes | 7 | 2 | 49 | 11 | 53 |
| c340 | 56 | Yes | Yes | 5 | 2 | 33 | 48 | 31 |
| c430 | 44 | Yes | Yes | 9 | 1 | 33 | 75 | 65 |
| c558 | 57 | Yes | Yes | 5 | 3 | 39 | 45 | 47 |
| c564 | 45 | Yes | Yes | 12 | 4 | 77 | 73 | 97 |
p1 = probability of finding a germline mutation inMLH1 or MSH2.
p2 = probability of finding a germline mutation inMLH1 or MSH2; the alternative formula.