Proportion of women with VYOC with heterozygous PVs in BRCA1/2 and MMRD genes
| Gene | Female carriers (n) | OC <30 (%) | OR | P value | OC 30–34 (%) | OR | P value |
| BRCA1 | 2005 | 1 (0.05) | 0.05 | 0.003 | 6 (0.30) | 0.23 | 0.02 |
| BRCA2 | 1999 | 0 (0.00) | NA | 0.007 | 3 (0.15) | 0.12 | 0.004 |
| MSH2 | 393 | 4 (1.02) | Ref | NA | 5 (1.29) | Ref | NA |
| MLH1 | 278 | 0 (0.00) | NA | NA | 0 (0.00) | NA | 0.013 |
| MSH6 | 169 | 0 (0.00) | NA | NA | 0 (0.00) | NA | 0.06 |
| PMS2 | 70 | 1 (1.43) | NA | NA | 0 (0.00) | NA | 0.36 |
MMRD, mismatch repair deficiency; NA, Not Applicable; OC, ovarian cancer; PV, pathogenic variant; Ref, reference population; VYOC, very young onset ovarian cancer.