Mapping of the murine and rat Facc genes and assessment of flexed-tail as a candidate mouse homolog of Fanconi anemia group C.

Fanconi anemia is a rare, autosomal recessive disorder characterized at the cellular level by a combination of hypersensitivity to DNA-damaging agents and chromosomal instability. Clinical features include pancytopenia, often associated with specific congenital malformations, and a predisposition to leukemia. We previously cloned the gene defective in Fanconi anemia group C by complementation of the intrinsic sensitivity of Fanconi anemia cells to DNA cross-linking agents, and we recently cloned its mouse homolog (Facc). In this report, we localized Facc to mouse Chromosome (Chr) 13 and its rat homolog to rat Chr 17. A previously described anemic mouse mutant, flexed-tail, maps to the same chromosomal region. Differences were detected between DNA of the flexed-tail and congenic mice, indicating the proximity of the Facc probe to the disease mutation. Analysis of flexed-tail RNA did not reveal detectable difference in Facc message level or size between flexed-tail and congenic mice. On this basis, we conclude that, although flexed-tail remains a candidate for Fanconi anemia in the mouse, there is no evidence currently that Facc is mutated in flexed-tail mice.