Breast and/or ovarian cancer: genes and variants
Breast and/or ovarian cancer is linked to 12 analyzed proteins (TP53, CHEK2, RAD51D, PMS2, BARD1, MLH1, STK11, RAD51C and 4 more). 5 DNA variants are known to cause it; 174 more are uncertain, and 0 of those already look disease-causing on computable evidence.
Last updated 2026-09-30. Research information, not medical advice.
Genes linked to Breast and/or ovarian cancer
TP53: Cellular tumor antigen p53
It coordinates transcriptional responses to DNA damage and other cellular stresses, promoting cell-cycle arrest, senescence, DNA repair, or apoptosis when appropriate. Loss of this tumor-suppressive control is one of the most common events in cancer, while germline pathogenic variants cause Li-Fraumeni syndrome.
3 disease-causing and 8 uncertain variants in TP53 are linked to Breast and/or ovarian cancer.
CHEK2: Serine/threonine-protein kinase Chk2
It propagates DNA-damage checkpoint signals to proteins controlling cell-cycle arrest, repair, and apoptosis. Germline loss-of-function variants confer moderate cancer susceptibility, especially for breast cancer, while risk estimates depend on the specific allele and family context.
1 disease-causing and 25 uncertain variants in CHEK2 are linked to Breast and/or ovarian cancer.
RAD51D: DNA repair protein RAD51 homolog 4
It supports RAD51-mediated homologous recombination and chromosome stability after DNA double-strand breaks. Heterozygous loss-of-function variants confer substantial ovarian-cancer risk and a more moderate increase in breast-cancer susceptibility.
1 disease-causing and 15 uncertain variants in RAD51D are linked to Breast and/or ovarian cancer.
PMS2: Mismatch repair endonuclease PMS2
Together with MLH1, it provides endonuclease activity needed to complete DNA mismatch repair after replication errors are recognized. Germline loss-of-function variants cause Lynch syndrome, while biallelic variants cause constitutional mismatch-repair deficiency.
0 disease-causing and 31 uncertain variants in PMS2 are linked to Breast and/or ovarian cancer.
BARD1: BRCA1-associated RING domain protein 1
It forms a heterodimer with BRCA1 that supports homologous recombination, DNA-damage signaling, and ubiquitin-dependent regulation at damaged chromatin. Germline loss-of-function variants confer increased breast-cancer susceptibility, particularly for some aggressive subtypes.
0 disease-causing and 16 uncertain variants in BARD1 are linked to Breast and/or ovarian cancer.
MLH1: DNA mismatch repair protein Mlh1
The protein partners with PMS2 to form MutL alpha, a core complex in post-replicative DNA mismatch repair. By helping correct copying errors in DNA, MLH1 protects genome stability, and inherited MLH1 variants are a major cause of Lynch syndrome.
0 disease-causing and 14 uncertain variants in MLH1 are linked to Breast and/or ovarian cancer.
STK11: Serine/threonine-protein kinase STK11
It activates AMPK-family kinases to coordinate cellular energy sensing, polarity, and growth restraint. Germline loss-of-function variants cause Peutz-Jeghers syndrome and its associated cancer predisposition, while somatic loss is common in lung and other cancers.
0 disease-causing and 14 uncertain variants in STK11 are linked to Breast and/or ovarian cancer.
RAD51C: DNA repair protein RAD51 homolog 3
It participates in RAD51-paralog complexes that promote homologous-recombination repair and restart damaged replication forks. Heterozygous loss-of-function variants increase ovarian and breast-cancer risk, while biallelic variants can cause Fanconi anemia.
0 disease-causing and 11 uncertain variants in RAD51C are linked to Breast and/or ovarian cancer.
CDH1: Cadherin-1
Its E-cadherin-mediated adhesion preserves epithelial architecture and suppresses inappropriate cell detachment and invasion. Germline loss-of-function variants cause hereditary diffuse gastric cancer syndrome and substantially increase diffuse gastric and lobular breast-cancer risk.
0 disease-causing and 10 uncertain variants in CDH1 are linked to Breast and/or ovarian cancer.
BRIP1: Fanconi anemia group J protein
It unwinds DNA structures and works with BRCA1 and the Fanconi-anemia pathway to repair damaged replication intermediates and interstrand crosslinks. Biallelic loss causes Fanconi anemia group J, while heterozygous loss-of-function variants increase ovarian-cancer risk.
0 disease-causing and 9 uncertain variants in BRIP1 are linked to Breast and/or ovarian cancer.
MSH2: DNA mismatch repair protein Msh2
The protein forms mismatch-recognition complexes with MSH6 or MSH3 that detect base mismatches and insertion-deletion loops in DNA. This first step of mismatch repair helps preserve genome integrity, and inherited MSH2 variants are associated with Lynch syndrome.
0 disease-causing and 7 uncertain variants in MSH2 are linked to Breast and/or ovarian cancer.
MSH6: DNA mismatch repair protein Msh6
Together with MSH2, it recognizes single-base mismatches and small insertion-deletion loops during DNA replication and initiates mismatch repair. Germline loss-of-function variants cause Lynch syndrome, while biallelic variants can cause constitutional mismatch-repair deficiency.
0 disease-causing and 6 uncertain variants in MSH6 are linked to Breast and/or ovarian cancer.
Weakly linked (only a few uncertain records): PALB2, ATM and PTEN.
Known disease-causing variants in Breast and/or ovarian cancer
| Variant | Position | Protein part | Clinical label |
|---|---|---|---|
| CHEK2 R145W | 145 | FHA | Disease-causing (★★) |
| RAD51D S207L | 207 | Disease-causing (★★) | |
| TP53 R158H | 158 | DNA binding | Disease-causing (★★) |
| TP53 R213Q | 213 | DNA binding | Disease-causing (★★) |
| TP53 R267W | 267 | DNA binding | Disease-causing (★★) |
Same protein, different disease
- Li-Fraumeni syndrome is also caused by TP53 variants; they fall mostly in different places as the Breast and/or ovarian cancer variants (188 disease-causing).
- Adrenocortical carcinoma, hereditary is also caused by TP53 variants; they fall mostly in different places as the Breast and/or ovarian cancer variants (23 disease-causing).
- Acute myeloid leukemia is also caused by TP53 variants; they fall mostly in different places as the Breast and/or ovarian cancer variants (6 disease-causing).
- Familial cancer of breast is also caused by TP53 variants; they fall mostly in different places as the Breast and/or ovarian cancer variants (5 disease-causing).
- Glioma susceptibility 1 is also caused by TP53 variants; they fall mostly in different places as the Breast and/or ovarian cancer variants (5 disease-causing).
- CHEK2-related cancer predisposition is also caused by CHEK2 variants; they fall mostly in different places as the Breast and/or ovarian cancer variants (3 disease-causing).
- Familial cancer of breast is also caused by CHEK2 variants; they fall mostly in different places as the Breast and/or ovarian cancer variants (3 disease-causing).
Diseases related to Breast and/or ovarian cancer
- Gastric cancer, also linked to BARD1, BRIP1, CHEK2, MLH1 and 5 more
- Ovarian cancer, also linked to BARD1, BRIP1, CDH1, MLH1 and 4 more
- Hereditary breast ovarian cancer syndrome, also linked to BARD1, BRIP1, CDH1, CHEK2 and 4 more
- Breast-ovarian cancer, familial, susceptibility to, 1, also linked to BRIP1, MSH2, RAD51C, RAD51D and 2 more
- Familial cancer of breast, also linked to BARD1, BRIP1, CDH1, CHEK2 and 1 more
- Colorectal cancer, also linked to CHEK2, MLH1, MSH2, MSH6 and 1 more
- Hereditary nonpolyposis colon cancer, also linked to CHEK2, MLH1, MSH2, MSH6 and 1 more
- Endometrial carcinoma, also linked to CDH1, MLH1, MSH2, MSH6 and 1 more
- Lynch syndrome, also linked to MLH1, MSH2, MSH6 and PMS2
- Hereditary nonpolyposis colorectal neoplasms, also linked to MLH1, MSH2, MSH6 and PMS2
- Mismatch repair cancer syndrome, also linked to MLH1, MSH2, MSH6 and PMS2
- Familial ovarian cancer, also linked to BRIP1, RAD51C and RAD51D
Frequently asked questions
Which genes are linked to Breast and/or ovarian cancer?
In CATVariant, Breast and/or ovarian cancer is linked to 12 analyzed proteins: TP53 (Cellular tumor antigen p53), CHEK2 (Serine/threonine-protein kinase Chk2), RAD51D (DNA repair protein RAD51 homolog 4), PMS2 (Mismatch repair endonuclease PMS2), BARD1 (BRCA1-associated RING domain protein 1), MLH1 (DNA mismatch repair protein Mlh1) and 6 more.
How many genetic variants are linked to Breast and/or ovarian cancer?
187 variants: 5 are classified as disease-causing (pathogenic or likely pathogenic) in ClinVar and 174 are of uncertain significance or have conflicting reports.
Which uncertain variants in Breast and/or ovarian cancer look disease-causing?
None of the uncertain variants currently reaches the likely-pathogenic range on computable evidence alone.
About this data
Variant–disease links come from ClinVar, Open Targets and UniProt, pooled from the latest public CATVariant analysis of each human protein. Evidence scores use the ACMG/AMP Bayesian points scale with computable criteria only (position among known disease variants, rarity in gnomAD, calibrated predictors, deep mutational scanning); there is no family or patient data, so they prioritise variants for expert review and never classify them.
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