Table 1. Clinical features of Lynch syndrome families with exon 8 deletion of MSH2 gene.
| Family ID | Clinical criteria | No. of individuals affected by LS cancers | Median age at onset of the first LS cancer (min–max age) | No. of CRC | No. of EC (OC) | No. of GC (SBC) | No. of PC | No. of UUC | No. of tumors with MSI-H/total | No. of tumors with loss of MSH2-MSH6/total | No. of individuals affected by non LS cancers or unknown site | Affected relatives for confirmatory testing. No. positive for the deletion/total | Healthy relatives with predictive testing. No. positive for the deletion/total |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| A | AC-I | 8 | 43 (28–50) | 7 | 0 (0) | 1 (0) | 0 | 0 | 1/1 | 1/1 | 1 | 0 | 0/2 |
| B | BR | 2 | − (33–69) | 1 | 0 (0) | 0 (1) | 1 | 0 | 1/1 | 1/1 | 1 | 0 | 1/2 |
| C | AC-II | 16 | 42 (29–61) | 7 | 3 (1) | 3 (0) | 4 | 1 | 3/3 | 3/3 | 1 | 4/4 | 11/21 |
| D | BR | 3 | 44 (32–45) | 2 | 1 (0) | 0 (0) | 0 | 0 | 1/1 | 1/1 | 3 | 0 | 0 |
| E | AC-II | 10 | 49.5 (28–62) | 9 | 1 (0) | 0 (0) | 0 | 0 | 1/1 | 1/1 | 1 | 1/1 | 3/5 |
| F | AC-II | 5 | 43 (39–55) | 3 | 2 (1) | 0 (1) | 0 | 0 | 1/1 | 1/1 | 1 | 1/1 | 3/4 |
| G | AC-II | 7 | 40* (38–40) | 7 | 0 (1) | 1 (0) | 0 | 0 | 1/1 | 1/1 | 0 | 0 | 0 |
| H | AC-II | 5 | 43 (40–48) | 4 | 3 (0) | 0 (0) | 0 | 0 | 1/1 | 1/1 | 0 | 0 | 1/1 |
| L | BR | 4 | 50.5 (45–57) | 2 | 2 (0) | 0 (0) | 0 | 1 | 1/1 | 1/1 | 4 | 0 | 1/4 |
| M: I, II generation | AC-II | 6 | 49 (35–70) | 4 | 2 (0) | 0 (0) | 0 | 0 | 0 | 0 | 2 | 0 | 0 |
| M: III, IV generation | 20 | 42 (30–51) | 14 | 8 (2) | 1 (1) | 0 | 0 | 1/1a | 1/1b | 4 | 9/9 | 14/27 | |
| N | AC-I | 4 | 48 (42–50) | 4 | 0 (0) | 0 (0) | 0 | 0 | 1/1 | 1/1 | 3 | 0 | 0/3 |
| P | AC-II | 6 | 38.5 (35–49) | 5 | 1 (1) | 0 (0) | 0 | 0 | 1/1 | 1/1 | 0 | 3/3 | 1/3 |
| Q | AC-I | 5 | 40 (33–52) | 5 | 0 (0) | 1 (0) | 0 | 0 | 2/2 | 2/2 | 0 | 1/1 | 3/7 |
Abbreviations: AC-I, Amsterdam criteria type 1; AC-II, Amsterdam criteria type 2; LS, Lynch syndrome; CRC, colorectal cancer; EC-OC, endometrial and ovarian cancer; GC-SBC, gastric and small bowel cancer; IHC, immunohistochemistry; PC, pancreatic cancer; UUC, upper urinary cancer.
Clinical criteria: BR, AC-I, AC-II, number of individuals affected by LS, tumors: CRC, EC-OC, GC-SBC, PC, UUC. No hepatobiliary cancers were present. Given the uncertain diagnosis, central nervous system tumors and skin cancer were not taken into consideration.
*Median age calculated on three affected individuals.
a
Only one microsatellite (BAT26) was tested.
b
IHC for MSH6 was not performed.