What is Fanconi anemia (FA)?

Fanconi anemia (FA) is a rare, inherited failure of bone marrow, the spongy tissue in the center of bones, to produce sufficient blood cells. Normally, bone marrow stem cells produce red cells, white cells and platelets.

  • Red cells are the blood cells that carry oxygen to the body.
  • White cells are infection-fighting blood cells.
  • Platelets are disc-shaped cells that are necessary for blood clotting in response to injury.

A deficiency in producing red blood cells, the blood cells that carry oxygen to the body, is termed anemia. In FA, red blood cells may also be abnormally large, impairing their function.

Sometimes, the bone marrow will make immature white cells (myoblasts, usually called blasts) instead of healthy white cells. Blasts interfere with the production of normal blood cells.

Because of the failure of the bone marrow in FA, patients with the condition are at increased risk of developing leukemia, a type of blood cancer. Survivors to adulthood are more likely to develop solid tumors.

About 75 percent of children who inherit FA have birth defects, including abnormal pigment, short stature and irregularities of their thumbs.

Who is at risk for Fanconi anemia (FA)?

About one person in 360,000 people in the United States is born with FA; one of every 300 is a carrier. Jews of Eastern European descent (Ashkenazi Jews) have a one in 90 chance of being a carrier, and one in 30,000 is born with it. The other ethnic group that has a higher risk is people native to South Africa.

What is the cause of Fanconi anemia (FA)?

At least 19 genes are known to be responsible for FA. Inheriting abnormal gene from both parents causes the disorder. With both parents having the same abnormal gene, the chance of a child inheriting FA is about 25 percent. People who inherit one copy of abnormal gene but don’t have FA can still pass the gene to their children.

What are signs and symptoms of Fanconi anemia (FA)?

  • Birth defects can be an early indicator. These may include abnormalities in the thumbs, such missing thumbs, more than two thumbs or oddly shaped thumbs.
  • Skin discoloration which may include café au lait spots (coffee-colored spots on the skin)
  • Unusually short stature, abnormal ears or kidney defects
  • Low birth weight and/or slow development
  • First sign of blood marrow failure: bruising and petechiae, or small purplish red spots caused by bleeding in vessels just underneath the skin. Fatigue from anemia is also common, as are infections due to an insufficient number of white blood cells being produced.
  • Other abnormalities of the head and face, neck, spine, eyes, ears, heart and lungs

Adults with FA can have underdeveloped sex organs. Women may start menstruating late, have difficulty becoming pregnant and start menopause sooner than women without FA.

Last reviewed by a Cleveland Clinic medical professional on 10/09/2018.


  • National Heart, Lung, and Blood Institute. What is fanconi anemia? Accessed 10/15/2018.
  • Genetics Home Reference. Fanconi anemia. Accessed 10/15/2018.
  • Alter BP. Fanconi anemia and the development of leukemia. Best Pract Res Clin Haematol. 2014 Sep-Dec; 27(3-4):214–21.

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