FANCB Gene - Fanconi Anemia Complementation Group B | Function, Mutations & Disease

FANCB encodes a protein that is a component of the Fanconi anemia (FA) core complex, which is essential for the repair of DNA interstrand crosslinks (ICLs). The FA core complex monoubiquitinates FANCD2 and FANCI, targeting them to chromatin to facilitate downstream repair. FANCB is required for the stability and nuclear localization of the core complex. Mutations in FANCB cause Fanconi anemia complementation group B, an X-linked recessive disorder characterized by bone marrow failure, congenital abnormalities, and predisposition to acute myeloid leukemia and solid tumors.

Tissue Expression

Cell Line Expression

Hotspot Mutations

Mutation functional classification

• Fanconi anemia pathway (Reactome R-HSA-6783310)

• DNA interstrand crosslink repair (KEGG hsa03460)

• Homologous recombination (Reactome R-HSA-5693571)

FANCB is a 95 kDa nuclear protein that forms a subcomplex with FAAP100 and FANCL, which is the E3 ubiquitin ligase module of the FA core complex. It is essential for the monoubiquitination of FANCD2 and FANCI. FANCB contains a putative nuclear localization signal and is required for the nuclear accumulation of the FA core complex. The protein is highly conserved in vertebrates and is expressed at low levels in most tissues, with highest expression in testis.