Fanconi anemia is the most common of the inherited anemias and is associated with chromosomal instability. It occurs at a rate of 1/350,000 births, with a carrier frequency estimated to approximately 1 per 300 population. Clinically, it is characterized by diverse congenital abnormalities, bone marrow failure, and increased predisposition to develop acute myeloid leukaemia. Affected individuals appear normal and may not be diagnosed until hematopoiesis is compromised, which is usually not apparent before the age of 5-10 years.
Fanconi anemia is genetically heterogeneous. It is caused by mutation in one of the nine complementation groups identified thus far, referred to as FA-A, -B, -C, -D1, -D2, -E, -F, -G and -L. Most of the Fanconi anemia patients belong to complementation group FA-A due to mutations in the Fanconi anemia complementation group A (FANCA) gene. Recent studies suggest that the Fanconi anemia pathway of genome stabilization may be controlled by at least 11 different genes, including FANCI and FANCJ.