Fanconi anemia pathway (FA pathway)

The **Fanconi anemia pathway** is a multi-protein cellular mechanism responsible for repairing toxic DNA interstrand cross-links—lesions that covalently link both strands of the double helix and block replication and transcription. The canonical event is activation during S phase when replication forks encounter an ICL; an eight-member core complex (*FANCA*, *FANCB*, *FANCC*, *FANCE*, *FANCF*, *FANCG*, *FANCL* [E3 ligase], and *FANCM*) monoubiquitinates the heterodimeric ID complex (*FANCI*-*FANCD2*), which then recruits downstream effectors involved in homologous recombination-mediated lesion removal.[1][5] The integrity of this process preserves genomic stability by stabilizing stalled forks, coordinating translesion synthesis, mismatch repair, cytokinesis regulation,[6] selective autophagy,[8] and more. Biallelic germline mutations in any one of at least 22 FANC genes cause **Fanconi anemia**, characterized clinically by congenital malformations, progressive bone marrow failure due to stem cell attrition from unrepaired damage,[7] hypersensitivity to cross-linking agents like mitomycin C/platinum drugs,[4] chromosomal instability syndromes,[3] and high cancer risk—especially acute myeloid leukemia and solid tumors such as head-and-neck squamous cell carcinoma.[5] The "Fanconi anemia pathway" itself is not a single molecular target but rather an integrated network; thus it does not fit standard drug-target categories like receptor/enzyme/transporter. Instead it represents a critical tumor suppressor axis whose dysfunction creates vulnerabilities exploited therapeutically—for example through synthetic lethality with PARP inhibitors or use of cross-linking chemotherapy agents against cancers harboring FANC gene defects.[3] Because "Fanconi anemia pathway" refers collectively to many proteins acting together—not one discrete molecule—the entry should be flagged as problematic if strict molecular targeting information is required.

Other names

FA-BRCA pathwayFanconi anemia DNA repair pathwayFanconi anemia/BRCA DNA damage response network

Drugs do not directly target the "Fanconi anemia pathway" but rather exploit its deficiency or induce lesions repaired by it. - Induction of ICLs leading to cytotoxicity in cells unable to perform effective ICL repair due to defective FA genes. - Synthetic lethality via inhibition of parallel or compensatory pathways such as PARP inhibition in HR-deficient tumors.