Table 2.
Clinical and molecular characteristics of the patients tested for MLH1 epimutations
| CaseID | Sex | Family history of LS cancers (years at diagnosis) | Type of cancers and age at diagnosis (yrs) | MSI status | BRAF p.V600E** | MLH1 methylation in tumor | MMR gene variants |
|---|---|---|---|---|---|---|---|
| M40 | M | Father: colon (63y) | CRC 33 | MSI-H | nt | − | — |
| M45 | M | — | 1) CRC 33; 2) CRC 40 | MSI-H | WT | − | — |
| M46 | M | Brother: colon (61y) | CRC 43 | nt | nt | nt | — |
| M47 | M | Mother: stomach (71y); maternal uncle: unspecified (35y) | CRC 48 | MSI-H | WT | − | — |
| M49 | F | Daughter: rectum (40y); mother: colon (79y) | CRC 68 | MSI-H | nt | + | MLH1 c.1217G>A; p.Ser406Asn (Class 1) |
| M50 | F | Father: colon 74y; paternal 1st cousin: colon (70y); other paternal relatives with LS-related tumors (>70y) | CRC 52 | MSI-H | nt | nt | — |
| M55 | M | Brother: colon (60y) | 1) CRC 43; 2) CRC 63 | MSI-H | nt | nt | MLH1 c.1039-8T>A (Class 1) |
| M56 | F | Father: colon (81y); paternal uncle: bladder (52y) | CRC 43 | MSI-H | WT | + | — |
| M57* | M | — | DC 37 | MSI-H | WT | + | — |
| M58 | F | — | DC 34 | MSI-H | WT | nt | — |
| M60 | F | — | 1) EC 55; 2) UC 62; 3) CRC 66; 4) BC 76 | MSI-H | nt | + | MSH2 c.1511-9A>T (Class 1) |
| M66 | F | Father: colon (51y) | 1) BC 56; 2) CRC 57 | MSI-H | Mut | + | MLH1 c.1743G>A; p.Pro581Pro (NR; Class 3) |
| M69 | F | — | CRC 35 | MSI-H | nt | − | MLH1 c.1814A>C; p.Glu605Ala (NR; Class 3) |
| M70 | M | — | CRC 41 | MSI-H | WT | − | — |
*
This patient also had multiple intestinal polyps (mostly hamartomas) and was later found to be heterozygous for the pathogenic PTEN mutation p.Ser170Arg.27
*
*nt: not tested; WT: wild-type.