Fanconi anemia is a rare and serious inherited blood disorder that leads to bone marrow failure. It prevents bone marrow from making enough new blood cells for the body to work properly. Fanconi anemia can also cause bone marrow to make faulty blood cells. This can lead to serious health problems such as leukemia, a type of blood cancer.
Fanconi anemia is a type of aplastic anemia – a condition that causes the blood to have a lower than normal number of blood cells. In Fanconi anemia, the bone marrow does not make enough or stops making all three types of blood cells – red blood cells (to carry oxygen), white blood cells (to fight infection) and platelets (to help blood clot).
Although Fanconi anemia is a blood disorder, it can also affect many of the body’s other organs, tissues and systems. Children who inherit Fanconi anemia are at higher risk for birth defects and for developing certain cancers and other serious health conditions.
Fanconi anemia is different than Fanconi syndrome, a condition that affects the kidneys.
There are normally physical signs of this condition at birth, but some children with Fanconi anemia don’t show signs of Fanconi anemia until later in life. According to the Fanconi Anemia Research Fund, more than 60 percent of patients born with Fanconi anemia have at least one physical anomaly. The median lifespan for people with Fanconi anemia is 29 years, although some people live into their 50s.
Children with Fanconi anemia are commonly diagnosed with acute myeloid leukemia and myelodysplastic syndrome between the ages of 5 and 15.
When people with Fanconi anemia become adults, they’re at an increased risk of developing a wide range of cancers, including oral and bone cancers.
Fanconi anemia is often diagnosed at birth or soon after because it affects the way your bone marrow produces blood cells. When you don't have a sufficient number of blood cells you’ll begin to experience the following:
Aplastic anemia is characterized by a lack of energy due to low numbers of red blood cells, which help to oxygenate your blood. The symptoms of anemia include dizziness, headaches, and an inability to keep your hands and feet warm.
Certain types of birth defects will indicate that your infant has FA, including:
Bone defects, especially involving the thumbs and arms
Developmental problems can include:
Symptoms in Adults
Adults who are diagnosed later in life will usually experience a completely different set of symptoms. The symptoms in adults will usually affect the sexual organs or the reproductive system. The symptoms in women include:
Men with FA may experience fertility issues and have smaller-than-normal genitals.
Fanconi anemia is a genetic disease inherited in an autosomal recessive fashion. This means that an affected individual must inherit one defective gene from both their mother and father.
Each parent is a “carrier”. It is thought that approximately one person in 500 in the general population is a carrier. Carriers are not affected by the disease.
However, if two carriers have a child, there is a 25% chance that the child will be affected by Fanconi anemia, a 50% chance that the child will be a carrier and a 25% chance that the child will inherit two copies of the normal gene. Each subsequent pregnancy carries the same risks. Boys and girls are affected equally.
It is now understood that Fanconi anemia is not caused by a single gene. At least 11 different Fanconi anemia genes have been identified. All of these genetic defects result in impairment in the ability to repair DNA rendering the chromosomes, which carry the body’s genetic blueprint, susceptible to damage. Researchers are currently investigating whether specific gene defects are associated with particular features of Fanconi anemia.
Most patients are diagnosed before the age of 12; in rare cases, symptoms don’t present until adulthood. A child’s doctor may order the following tests:
Doctors may, through tests called amniocentesis or chorionic villus sampling (CVS) test the fetuses of pregnant women who have a family history of Fanconi anemia. These tests remove small samples of amniotic fluid or placenta tissue to test for genetic defects.
Fanconi anemia is a genetic disorder with no cure. Treatment is based on how low or abnormal the blood counts are and the age of the patient.
Treating Fanconi anemia can include both short-term and long-term strategies:
Short-term: to monitor the disease and control symptoms.
Long-term: to improve quality of life and extend lifespan
Blood and bone marrow stem cell transplant: In this procedure, blood stems cells are taken from a healthy donor (often a family member) to replace the abnormal stem cells. The unhealthy bone marrow cells of the person with Fanconi anemia are destroyed using radiation and/or chemotherapy. Healthy stem cells from the donor are then infused through a vein and will travel to the bone, where they can grow and produce normal bone marrow and blood cells. Stem cell transplant is the current standard treatment for Fanconi anemia that is causing major bone marrow failure.
Growth factors: are natural or man-made growth substances that help the body make more red and white blood cells. Research on using growth factors to stimulate bone marrow cells for treating aplastic anemia and Fanconi anemia is ongoing.
Androgen therapy: uses man-made male hormones to help the body make more red blood cells and platelets for long periods. This therapy does not work as well for increasing the white blood cell count.
Surgery: will correct birth defects caused by Fanconi anemia. For example, children with the disorder who have digestive problems or heart or bone abnormalities (problems) may need surgery to repair problems that affect nutrition, growth and survival. For some young patients who have these problems, their doctor may want to test for Fanconi anemia.
Gene therapy: is being studied by researchers looking for ways to replace the defective genes involved in Fanconi anemia with normal, healthy ones. It is hoped that these genes will make proteins that can repair and protect bone marrow cells.
Genetic testing and counseling: can benefit families, because Fanconi anemia is an inherited disorder (passed down through families).