Basics of Fanconi Anemia

Doctor examining boy in office
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Fanconi Anemia is a rare inherited bone marrow failure syndrome characterized by pancytopenia (low white blood cells, red blood cells, and platelets) and physical abnormalities. Prevalence is higher in Ashkenazi Jews, Roma population of Spain, and black South Africans. It should not be confused with Fanconi's syndrome, a disease of the kidneys. Most patients are diagnosed before 10 years of age.

Signs and Symptoms of Fanconi Anemia

More than 50% of patients have physical abnormalities. These may include:

  • Skin changes - hypopigmented spots (lighter than surrounding skin) or café-au-lait spots (coffee colored areas)
  • Short stature
  • Thumb abnormalities
  • Brain abnormalities - small head size, increased fluid in the brain
  • Absent or malformed kidneys
  • Abnormalities of genitalia 
  • Developmental delay

As the blood cell counts drop, symptoms of pancytopenia may develop.

Diagnosis of cancer can be the initial presentation. People with Fanconi Anemia are at increased risk of developing:

  • Acute Myeloid Leukemia
  • Myelodysplastic syndrome
  • Head and neck cancers
  • Brain tumors
  • Wilms tumor (cancer of the kidney)
  • Gastrointestinal (GI) cancers)
  • Vulvar and anal cancer


The process of being diagnosed can be a slow one, as the presentation usually evolves over time. A low platelet count is usually the first sign of problems. Then over time, the white blood cell count decreases followed by anemia. The anemia is described as macrocytic meaning that the red blood cells are larger than normal. These laboratory findings combined with physical abnormalities reviewed above suggest Fanconi Anemia.

Patients with Fanconi Anemia are also at increased risk of developing cancer. Cancer presenting at an unusually early age can be the initial presentation in some patients. Also, it may be picked up if multiple members of the same family develop cancer.  

When Fanconi Anemia is suspected, blood is sent for a special laboratory test called the chromosomal breakage. The genetic defect in Fanconi Anemia prevents the chromosomes from being able to repair themselves properly leading to bone marrow failure and cancer at an early age. If the chromosomal breakage test is consistent with Fanconi Anemia, genetic testing can also be sent. In addition to confirming the diagnosis, this information allows gives the family more information about the risk of having more children with this condition.  


Fanconi Anemia is usually passed down in an autosomal recessive pattern. This means both parents have to be a carrier for their child to have the disease. In this scenario, both parents are carriers and they have a 1 in 4 chance of having a child with Fanconi Anemia. More rarely, it is passed down in an X-linked fashion meaning the genetic change is on the X chromosome. In this case, a mother can pass the disease on to her sons.


Transfusions: Red blood cell and platelet transfusions are used to replenish supply as the bone marrow is unable to produce normal amounts. Transfusions are used to prevent symptoms of anemia (fatigue, tiredness) or thrombocytopenia (bleeding).  

Oxymetholone: Oxymetholone is an oral anabolic steroid that can be used to improve blood cell counts. This is generally used for patients who do not have siblings available to be bone marrow donors. 

Bone marrow transplantation: Bone marrow transplantation can be curative for pancytopenia, but does not decrease the lifelong risk of cancer. Best results are seen when matched siblings can be donors.  

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Article Sources

  • Bertuch A. Inherited aplastic anemia in children and adolescents. In: UpToDate, Post, TW (Ed), UpToDate, Waltham, MA, 2016.