Mastitis
diseaseOn this page
Also known as breast infectionbreast inflammationinflammation of breastinflammatory disease of breast
Summary
Mastitis (MONDO:0006849) is a disease with 1 GWAS associations across 8 studies and 15 clinical trials. Top therapeutic interventions include penicillin g, cefadroxil, and floxacillin. A subtype of breast disorder — broader associated-gene and molecular evidence is on the parent page (see Disease family below).
At a glance
- GWAS associations: 1
- Clinical trials: 15
Clinical features
No curated clinical features (Orphanet) for this disease.
Identifiers
Disease identifiers
| Field | Value |
|---|---|
| Canonical name | mastitis |
| Mondo ID | MONDO:0006849 |
| EFO | EFO:1001034 |
| MeSH | D008413 |
| DOID | DOID:10690 |
| NCIT | C53662 |
| SNOMED CT | 45198002 |
| UMLS | C0024894 |
| MedGen | 9901 |
| MedDRA | 10026883 |
| Is cancer (heuristic) | no |
Also known as: breast infection · breast inflammation · inflammation of breast · inflammatory disease of breast
Data availability: 1 GWAS association (8 studies).
Disease family
This is a subtype of breast disorder. Genetic, therapeutic, and trial evidence is largely curated at the broader-term level — see the parent page for the associated-gene cohort and molecular evidence.
Classification path: disease › human disease › disease by body system or component › breast disorder › mastitis
Related subtypes (14): breast abscess, hypertrophy of breast, fat necrosis of breast, breast angiomatosis, breast adenosis, benign mammary dysplasia, breast fibrocystic disease, familial juvenile hypertrophy of the breast, supernumerary breasts, isolated congenital breast hypoplasia/aplasia, syndromic breast hypoplasia/aplasia, breast neoplasm, lactation disease, breast implant illness
Subtypes (1): neonatal infective mastitis
Genetics & variants
GWAS landscape
1 GWAS associations across 8 studies. Top hits map to 0 distinct genes (as reported by GWAS).
Top associations by p-value
| rsID | p-value | Gene | Risk allele | Odds ratio |
|---|---|---|---|---|
| chr2:97882455 | 1e-07 | ? |
Top studies (by case count)
| Study | Lead author | Year | Cases | Controls | Title |
|---|---|---|---|---|---|
| GCST90474218 | UK Biobank Whole-Genome Sequencing Consortium | 2025 | 1,910 | 456,530 | Whole-genome sequencing of 490,640 UK Biobank participants. |
| GCST90080639 | Backman JD | 2021 | 987 | 208,795 | Exome sequencing and analysis of 454,787 UK Biobank participants. |
| GCST90084625 | Backman JD | 2021 | 987 | 208,795 | Exome sequencing and analysis of 454,787 UK Biobank participants. |
| GCST90436477 | Zhou W | 2018 | 723 | 406,978 | Efficiently controlling for case-control imbalance and sample relatedness in large-scale genetic association studies. |
| GCST90651919 | Liu TY | 2025 | 415 | 227,375 | Diversity and longitudinal records: Genetic architecture of disease associations and polygenic risk in the Taiwanese Han population. |
| GCST90482255 | Verma A | 2024 | 339 | 450,296 | Diversity and scale: Genetic architecture of 2068 traits in the VA Million Veteran Program. |
| GCST90474251 | UK Biobank Whole-Genome Sequencing Consortium | 2025 | 308 | 458,132 | Whole-genome sequencing of 490,640 UK Biobank participants. |
| GCST90727141 | Kim HI | 2026 | 158 | 43,868 | Exome sequencing and analysis of 44,028 British South Asians enriched for high autozygosity. |
Variant details and genetic-evidence tiers
Tier distribution (top 50 variants)
| Tier | Variants |
|---|---|
| Tier 1: coding | 0 |
| Tier 2: splice/UTR | 0 |
| Tier 3: regulatory | 0 |
| Tier 4: intronic/intergenic | 1 |
MAF distribution
| Bucket | Variants |
|---|---|
| common (>=0.05) | 0 |
| low_freq (0.01-0.05) | 0 |
| rare (<0.01) | 0 |
| unknown | 1 |
Functional consequences
| Consequence | Count |
|---|---|
| unknown | 1 |
Top variants
| rsID | Chr | Pos | Alleles | MAF | Consequence | Gene | p-value | Tier |
|---|---|---|---|---|---|---|---|---|
| chr2:97882455 | 1e-07 | Tier 4: intronic/intergenic |
Genes & proteins
No associated-gene cohort resolved for this disease. Atlas builds the molecular and therapeutic sections — associated genes, protein families, druggability, pathways, interactions, and drug associations — by aggregating over a disease’s associated genes (resolved via GWAS / GenCC / ClinVar / CIViC), and none resolved here. This is expected for antibody-mediated, autoimmune, or otherwise non-gene-defined conditions; the curated evidence for this disease is its clinical features, GWAS susceptibility, and clinical trials (above).
Function
No pathway enrichment — requires an associated-gene cohort.
Therapeutics
Drugs indicated for this disease
No approved or late-stage (phase ≥3) drug is indicated for this disease; the following are in earlier-phase trials only.
Earlier-phase candidates (phase 2, investigational — efficacy not yet established): Amoxicillin, Baricitinib, Cefdinir, Clavulanic Acid, Cloxacillin, Lactobacillus Acidophilus.
Clinical trials & evidence
Clinical trials
Clinical trials: 15.
Phase distribution (across all retrieved trials)
| Phase | Trials |
|---|---|
| Not specified | 13 |
| PHASE2/PHASE3 | 1 |
| PHASE1/PHASE2 | 1 |
Top trials by phase / activity
| NCT | Phase | Status | Title |
|---|---|---|---|
| NCT00716183 | PHASE2/PHASE3 | COMPLETED | Use of Probiotic Lactobacilli for the Treatment of Lactational Mastitis |
| NCT01505361 | PHASE1/PHASE2 | UNKNOWN | Study of a Probiotic Strain to Prevent Mastitis and to Eradicate GBS Colonization |
| NCT00405158 | Not specified | COMPLETED | Study of Acupuncture and Care Interventions for the Treatment of Breast Inflammation During Breastfeeding |
| NCT00620984 | Not specified | COMPLETED | Staphylococcus Aureus Carrier Status in Breastfeeding Mothers and Infants and the Risk of Lactation Mastitis |
| NCT01124448 | Not specified | COMPLETED | Global Effects of a Probiotic Strain on Lactating Women |
| NCT01631461 | Not specified | COMPLETED | Painful Breastfeeding and Bacterial or Yeast Infection |
| NCT02203877 | Not specified | COMPLETED | Evaluation of Lactobacillus Fermentum CECT5716 on the Incidence of Mastitis |
| NCT02755012 | Not specified | COMPLETED | Impact of Maternal Stress on Infant Stunting |
| NCT02794688 | Not specified | COMPLETED | Ductal Lavage in Non-lactating Female Women With Mastitis |
| NCT04032899 | Not specified | COMPLETED | Effect of Probiotics Consumed During Pregnancy on the Incidence of Mastitis |
| NCT04569136 | Not specified | COMPLETED | Physical Therapy Intervention for Puerperal Mastitis |
| NCT05021042 | Not specified | UNKNOWN | Identification of Biomarkers of Mastitis |
| NCT05132426 | Not specified | WITHDRAWN | Osteopathic Manipulative Treatment for Recurrent Mastitis |
| NCT05762016 | Not specified | UNKNOWN | Outcomes of a Novel Technique of Mini- Incision and Self-Express (MISE) for Breast Abscess |
| NCT05974956 | Not specified | COMPLETED | Effect of a Nursing Teaching Protocol on Mastitis Prognosis: Quasi-Experimental Research Design |
Drugs tested across these trials (top 30)
| Molecule | Max phase | Trials referencing |
|---|---|---|
| PENICILLIN G | 4 | 3 |
| CEFADROXIL | 4 | 1 |
| FLOXACILLIN | 3 | 1 |
| MALTODEXTRIN | 3 | 1 |
| CHEMBL1555813 | 0 | 1 |
| 17 | 0 | 1 |
Related Atlas pages
- Drugs: Penicillin G, Cefadroxil, Floxacillin, Maltodextrin