Fanconi anemia is a rare genetic syndrome characterized by developmental defects, bone marrow failure and increased cancer risk. A diagnosis of Fanconi Anemia usually requires detection of a pathogenic mutation in a Fanconi Anemia gene and/or a positive chromosomal breakage test. A variety of different inactivating mutations in FANCL have been described in a small subset of patients with Fanconi Anemia and patients with myeldodysplastic syndrome(less than 5%). Pathogenic mutations are often found in homozygous or compound heterozygous state. In addition, pathogenic variants in introns have been described that are not detected by this test.