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Fanconi Anemia

Last updated: 2003-09-11

Fanconi anemia is a blood disorder characterized by pancytopenia (deficiency of red blood cells, white blood cells and platelets), increased risk for cancer, and congenital birth defects.

The disease is highly variable and is frequently associated with cardiac, kidney and limb abnormalities. Short stature is commonly observed in children and adults with Fanconi anemia, and other growth measurements may also be below normal. Bleeding episodes and bruising are common, as are hormonal problems and infertility. The majority of individuals with Fanconi anemia are diagnosed during childhood, but many do not survive beyond young adulthood. This is frequently a result of leukemia or other cancers, which are due to bone marrow failure.

Treatment for Fanconi anemia is primarily preventive. Individuals with Fanconi anemia may pursue bone marrow transplantation on an experimental basis, however there is to date no consistently effective treatment. In order to detect cancers early, individuals with Fanconi anemia should arrange for frequent screenings. In addition, avoidance of sun exposure and other agents which may damage the chromosomes is imperative.

Although five subtypes of Fanconi Anemia exist, it is only Type C that occurs with increased frequency among individuals with Ashkenazi Jewish ancestry. It is estimated that approximately 1 in 89 Ashkenazi Jewish individuals are carriers of Type C. All types of Fanconi anemia are inherited in an autosomal recessive manner. Therefore parents of an affected child have a 1 in 4 (25%) chance in each future pregnancy to have another child with Fanconi anemia.

In the past, a diagnosis of Fanconi anemia was based on clinical observation and the results of laboratory studies. Cytogenetic analysis was used to reveal chromosome breakage, which is characteristic of Fanconi anemia. Carriers of Fanconi anemia cannot be reliably identified by chromosome breakage studies, and it was not until recently, when the gene for Fanconi anemia was isolated on chromosome 9, that identification of Fanconi anemia carriers became possible. One mutation in particular accounts for the vast majority of Ashkenazi Jewish carriers. Type C carrier testing is therefore available for Ashkenazi Jewish couples. In the event that both parents are found to be carriers of Fanconi Anemia Type C, prenatal diagnosis is available via either chorionic villus sampling (CVS) or amniocentesis.