Fanconi anemia (FA), named for Swiss pediatrician, Guido Fanconi, is one of the inherited anemias that leads to bone marrow failure (aplastic anemia). It is a recessive disorder: if both parents carry a defect (mutation) in the same FA gene, each of their children has a 25% chance of inheriting the defective gene from both parents. When this happens, the child will have FA.
There are at least seven FA genes: A, C, D2, E, F, G, and BRCA2 (as announced in the article entitled Biallelic Inactivation of BRCA2 in Fanconi Anemia in the July 26, 2002 edition of Science). Six of these genes have been cloned. These six account for more than 85% of the cases of Fanconi anemia. Mutations in FA-A and FA-C account for FA in 76% of patients worldwide.
FA occurs equally in males and females. It is found in all ethnic groups. Though considered primarily a blood disease, it may affect all systems of the body. Many patients eventually develop acute myelogenous leukemia (AML). Older patients are extremely likely to develop head and neck, esophageal, gastrointestinal, vulvar and anal cancers. Patients who have had a successful bone marrow transplant and, thus, are cured of the blood problem associated with FA still must have regular examinations to watch for signs of cancer. Many patients do not reach adulthood.
Fanconi anemia patients are usually smaller than average. FA usually reveals itself before children are 12 years old, but in rare cases no symptoms are present until adulthood. Patients may feel extreme fatigue and have frequent infections. Nosebleeds or easy bruising may be a first sign. Blood tests may reveal a low white cell, red cell or platelet count or other abnormalities. Sometimes myelodysplasia or AML is the first sign of FA.
What are the signs of FA?
FA is sometimes evident at birth, but because it is a rare condition, it may not be detected until later in childhood. The following symptoms are common among FA patients:
- Hand and arm anomalies: misshapen, missing or extra thumbs and/or incompletely developed or missing arm bones
- Skeletal anomalies of the hips, spine, or ribs
- Kidney problems, including missing or horseshoe kidney
- Skin discolorations
- Small head or eyes
- Mental retardation or learning disabilities
- Low birth weight
- Gastrointestinal difficulties
- Small reproductive organs in males (most FA individuals are infertile)
- Defects in tissues separating chambers of the heart
What are the effects of FA?
Though considered primarily a blood disease, FA can affect all systems of the body. FA patients are highly susceptible to head, neck, gynecological and/or gastrointestinal cancers as well as others. Many will develop acute myelogenous leukemia (AML). Those who have had a successful bone marrow transplant and thus, are cured of the blood problem associated with FA still must have regular examinations to watch for signs of cancer.
How many children have FA?
While the total number of FA patients is difficult to document, it is estimated that there are about 500 FA individuals in the US, and approximately 3,000 cases worldwide. Scientists also estimate that the carrier frequency (carriers are people carrying the defect in an FA gene, whose matching FA gene is normal) for FA is somewhere between 1 in 600 and 1 in 100. The International Fanconi Anemia Registry is managed by Dr. Arleen Auerbach at The Rockefeller University.
Why is finding a cure for FA important?
Curing FA is not merely important to these 3,000 patients and their families. Research has shown a relationship between the genetic activity of FA and breast, neck, head, other blood, and uterine cancers. Discoveries in FA genetic research have led to important breakthroughs for these other cancers. So while FA itself may be a rare disease, continued support for FA research indirectly supports research for those who are affected by FA as well as other can