Biomarkers used in the diagnosis of Lynch syndrome (HNPCC)
| Biomarker | Frequency | |
| Sporadic | Lynch syndrome | |
| Microsatellite instability (MSI) | 15% | >95% |
| BRAF V600E mutations | 50% of sporadic MSI | <1% |
| 5% of MSS | ||
| 10% overall | ||
| Mismatch repair protein loss by IHC | 10–15%, mostly MLH1 | ∼90% |
| MLH1 promoter hypermethylation | ∼99% of sporadic MSI | <1% |
| <1% MSS | ||
| 15% overall | ||
HNPCC, hereditary non-polyposis colorectal cancer; IHC, immunohistochemistry; MSS, microsatellite stable.