IHC loss and constitutional MMR pathogenic variant detection rates in all index ovarian cases tested
| Tested (n) | IHC loss (n) | IHC loss (%) | Tested for path_MMR (n) | Lynch syndrome (n) | Lynch syndrome (%) | |
| Any loss | 261 | 27 | 10.3 | 18 | 8 | 44.4 |
| MLH1 loss | 261 | 7 | 2.7 | 3 | 0 | 0.0 |
| Either MSH2 or MSH6 | 261 | 19 | 7.3 | 15 | 8 | 53.3 |
| MSH2 loss | 261 | 13 | 4.9 | 9 | 4 | 44.4 |
| MSH6 loss | 261 | 10 | 3.8 | 9 | 6 | 66.7 |
| MSH6 loss alone | 261 | 7 | 2.7 | 6 | 4 | 66.7 |
| PMS2 loss alone | 261 | 0 | 0.0 | 0 | 0 | – |
| No Loss | 234 | 0 | 0.0 | 15 | 1* | 6.7 |
*Ovarian clear cell carcinoma aged 59 years had exon 6–19 deletion of MLH1 with normal IHC –family met Amsterdam II criteria. She also carries a BRCA1 exon 13 duplication. She developed grade 3 triple negative breast cancer at 71 and sebaceous carcinoma at 67 years.
IHC, immunohistochemistry; MMR, mismatch repair.