Up until now we there are 146 cases known to have CMMRD in Europe. 145 patients ended up developing malignant turmors. Please see chart below for more details.
| Gene | Number of patients (families) | Average age at first malignancy (years) | Age group at first malignancy (years) | Percentage of patients with a second malignancy |
| MLH1/MSH2 | 32 (19) | 7.5 | 0.4-39 | 22 |
| MSH6 | 29 (17) | 8 | 2-31 | 34 |
| PMS2 | 85 (55) | 10 | 1-28 | 42 |
| Malignancies | Amount | Average age at diagnosis | Age range at diagnosis |
| Hematological cancer | 48 | 6 | 0.4-21 |
| Brain- and nervesystem tumors | 81 | 9 | 2-40 |
| LS-related tumors | 88 | 17 | 8-48 |
| Other | 8 | – | – |