Family pedigree pattern suggestive of germline PALB2 heterozygous carrier state in an asy...

Deterministic view of the source YAML entity. Clinical authority remains with the cited source IDs and reviewer sign-off state.

ID	`RF-PALB2-FAMILY-HISTORY-SUSPICION`
Type	Red flag
Status	reviewed 2026-05-19 \| pending_clinical_signoff
Diseases	`DIS-BREAST` `DIS-OVARIAN` `DIS-PDAC`
Sources	`SRC-NCCN-BREAST-2025` `SRC-NCCN-GENETIC-FAMILIAL-BREAST-OVARIAN-2025`

Red Flag Origin

Definition	Family pedigree pattern suggestive of germline PALB2 heterozygous carrier state in an asymptomatic individual who has NOT yet had multi-gene panel testing. PALB2 functions in the same homologous- recombination repair pathway as BRCA1/BRCA2, and carriers approach BRCA2 breast-cancer penetrance (lifetime ~33-58%). Triggers include any of (a) first- or second-degree relative with a confirmed PALB2 pathogenic / likely-pathogenic variant; (b) family-history pattern resembling BRCA-style HBOC but with negative BRCA1/2 testing in affected relative (PALB2 is the most common moderate-penetrance finding in BRCA-negative BRCA-like pedigrees); (c) family history of pancreatic adenocarcinoma in ≥2 first/second-degree relatives combined with breast cancer in a close relative — PALB2 is the second most-common gene (after BRCA2) identified in familial PDAC-breast kindreds; (d) early-onset (<50y) breast...
Clinical direction	investigate
Category	other

Trigger Logic

{
  "any_of": [
    {
      "finding": "family_palb2_known_pathogenic_variant",
      "value": true
    },
    {
      "finding": "family_brca_like_pedigree_brca_negative",
      "value": true
    },
    {
      "finding": "family_breast_and_pancreatic_cluster",
      "value": true
    },
    {
      "finding": "family_early_onset_breast_brca_negative",
      "value": true
    }
  ],
  "type": "lab_value"
}

Notes

v0.3 Wave M suspicion variant — pre-testing family-history- suspicion counterpart to RF-PALB2-CONFIRMED-CARRIER. Fires when family pedigree pattern suggests PALB2 carrier state but germline panel testing has not yet been completed. Standard pathway = referral for genetic counseling + multi-gene HBOC/PDAC-inclusive panel. If panel returns positive for PALB2, the patient transitions to the RF-PALB2-CONFIRMED-CARRIER pathway (IND-PALB2-CARRIER- PREVENTION-SURVEILLANCE for standard track — BRCA-style management given near-BRCA2 penetrance: annual breast MRI + mammography from age 30, pancreatic surveillance for FDR-of-PDAC carriers, RRSO discussion deferred to BRCA-style threshold given lower ovarian penetrance). Distinct trigger findings from the confirmed-carrier RF (carrier RF fires on `germline_palb2_pathogenic_variant_ confirmed`; suspicion RF fires on family-history-based findings only). STUB pending two-Clinical-Co-Lead signoff per CHARTER §6.1 dev-mode. Sources cite NCCN Genetic/Familial High-Risk: Breast, Ovarian, and Pancreatic v2.2025 PALB2 testing criteria + Yang et al. JCO 2020 lifetime risk estimates.

Used By

Indications

IND-PALB2-SUSPICION-PREVENTION-EMPIRICAL-SURVEILLANCE - IND-PALB2-SUSPICION-PREVENTION-EMPIRICAL-SURVEILLANCE
IND-PALB2-SUSPICION-PREVENTION-TESTING - IND-PALB2-SUSPICION-PREVENTION-TESTING