Fanconi Anemia Complementation Group B (FANCB)

FAAP95 is subject to total inactivation by methylation and that inactivation seems to be skewed toward the mutated allele. Because X inactivation takes place early in embryogenesis, selection over many subsequent cell generations may lead to almost complete overgrowth by normal cells. The presence of the FAAP95 gene as a single active copy and essentiality for a functional Fanconi anemia-BRCA pathway make FAAP95 a potentially vulnerable component of the cellular machinery that maintains genomic integrity. Although germline mutations in FAAP95 resulting in FANCB are exceedingly rare, somatic FAAP95 mutations might occur at the average spontaneous mutation rate. The occurrence of such Fanconi anemia-like cells may contribute to oncogenesis.