Number of polyps | Sporadic or autosomal recessive* | Autosomal dominant | ||
---|---|---|---|---|
Total | Biallelic | Total | Biallelic | |
For assessing the mode of inheritance, first and second degree relatives were considered as patients if they had ⩾3 adenomas (or 2 at young age, ie, <40 years) and/or CRC. The family history was considered dominant if patients occurred in at least two generations, and recessive if patients were siblings. The family history for three index patients was not available and these three were not included in this table. | ||||
*26 patients with a recessive pattern of inheritance and 38 apparently sporadic cases with 9 and 15 biallelic MYH patients, respectively. | ||||
1–9 | 5 | None | 27 | None |
10–99 | 37 | 17 (46%) | 45 | 7 (16%) |
100–1000 | 10 | 3 (30%) | 14 | 4 (29%) |
>1000 | 1 | None | None | None |
Polyposis | 3 | 2 (67%) | 13 | 4 (31%) |
Multiple | 7 | 2 (29%) | 3 | None |
Unknown | 1 | None | 1 | None |
Total | 64 | 24 (38%) | 103 | 15 (15%) |