Fanconi Anemia

Inherited anemia leading to bone marrow failure, myelogenous leukemia, and, in older patients, many cancers (head and neck, esophageal, gastrointestinal, vulvar, anal).

Type I Fanconi Pancytopenia.

Genetically inherited anemia. Named after the Swiss pediatrician, Guido Fanconi.

Rare, with carrier frequency of 1:300 in the general population (1:89 in the Ashkenazi Jewish population). Occurs equally in males and females and is found in all ethnic groups. The International Fanconi Anemia Registry (Rockefeller University, New York, NY) maintains case data on more than 3000 patients.

Fanconi anemia (FA) comprises a group of monogenic autosomal recessive disorders resulting from mutations in one of eight Fanconi anemia genes (A, B, C, D1, D2, E, F, G). Although caused by rather simple mutations, the disorder shows a complex phenotype with many features, including developmental abnormalities, severe anemia, and/or eventually leukemia and various cancers. Many patients die during their mid-teen years. Mutations in FA-A and FA-C account for 76% of patients worldwide.

Spontaneous chromosomal aberrations associated with hypocellular marrow, pancytopenia, and constitutional aplastic anemia.

Usually diagnosed by age 6 years, after onset of hematologic abnormalities. It may be diagnosed as early as the neonatal period while investigated for other associated anomalies. Diepoxybutane, a DNA cross-linking agent, is a unique marker for Fanconi anemia cells. Currently, the definitive diagnostic test is a chromosome breakage test with a chemical, either diepoxybutane or mitomycin C, that cross-links DNA. Normal cells are able to correct most of the damage caused by these agents, whereas Fanconi anemia cells show marked chromosome breakage. These tests can be performed prenatally on cells from chorionic villi or from the amniotic fluid.

Pancytopenia, with mean survival of 5 years after diagnosis, low birth weight, skeletal anomalies (hips, spine, ribs), short stature, microcephaly, microphthalmia, microstomia, radial ray/thumb abnormalities, polydactyly, syndactyly, misplaced radial artery, renal abnormalities, cardiac defects, and developmental delay.

Check a complete blood cell count (CBC) for anemia and thrombocytopenia. Check electrolytes in presence of renal defects. Complete physical evaluation must be obtained to eliminate the presence of cardiac defects.

Maintain oxygen carrying capacity with red blood cell transfusion. Anticipate need for platelet transfusion. Avoid central neuraxial anesthesia techniques in presence of coagulopathy. Direct laryngoscopy and tracheal intubation can be difficult in the presence of macrostomia.

Prophylactic antibiotic must be considered in case of cardiac defect.

Bloom Syndrome: Autosomal recessive inherited disorder characterized by prenatal and postnatal growth retardation, photosensitivity, telangiectasias, skin pigment anomalies, and increased risk of malignancies most likely caused by chromosomal instability. Most interchanges occur between homologous chromosomes, not between nonhomologous chromosomes as in Fanconi anemia.

Blackfan-Diamond Syndrome: Congenital hypoplastic anemia manifesting in the first year of life, with increased risk for leukemia. High adenosine deaminase activity in the blood.

TAR Syndrome: Rare condition associated with ...