What Causes Fanconi Anemia?
Fanconi anemia is an inherited disease caused by changes (mutations) in certain genes, known as FA genes. Experts have found 23 different FA genes. The disease occurs when there is a change (mutation) in one of these 23 genes.
Children inherit Fanconi anemia from their parents. In most subtypes of FA (except subtype FANC B and FANC R), both parents must have the change in the same FA gene for a child to have Fanconi anemia. The parents are “carriers” of the changed gene. They typically do not have the condition themselves.
What Type of Doctor Cares for People with Fanconi Anemia?
The progression of the disease varies in patients and requires regular, life-long monitoring. Treatment strategies depend on the stage of the condition and the extent of physical traits and complications that result from the condition.
Fanconi anemia birth defects can affect almost every system in the body from head to toe. Children with FA need comprehensive care from a hematologist (a doctor who specializes in blood diseases) and other doctors who have experience with FA. Working together, these specialists can treat FA and the complications of the condition.
Fanconi Anemia Symptoms
Fanconi anemia can be identified at birth, during early childhood or during young adulthood. The types and severity of symptoms can be very different from person to person.
Signs and Symptoms at Birth or Very Early in Life
Doctors may suspect that a very young child has Fanconi anemia if they see one or more of the physical traits listed below. These traits occur in about 75% of people with FA.
Growth deficiency: low birth weight, prenatal and/or postnatal short stature
- Skeletal anomalies—the most common being no thumb or radius bone (one of the two bones in the forearm)
- Abnormal skin pigmentation —dark or light-colored birthmarks
- Structural anomalies of the kidney and/or heart
- Small head or eyes
- Gastrointestinal (bowel) problems
- Abnormalities in the urinary tract, colon or rectum
- Small reproductive organs in males
Some newborns or young children with Fanconi anemia do not have any obvious physical signs of the disease. Therefore, they may not be diagnosed early in life.
Signs and Symptoms During Childhood
During childhood, children with FA develop bone marrow failure. This gets worse over time. Blood cells (including red blood cells, white blood cells and platelets) decrease. This decrease causes symptoms such as:
- Unexplained fatigue
- Frequent infections
- Frequent nosebleeds
- Easy bruising
- Blood in the stool or urine
These symptoms can develop over a few years or months. They can also appear suddenly. The average age for marrow failure is about 7.5 to 8 years old. This means that half of the children can develop marrow failure before this age and other half after this age.
Failure to thrive and poor growth may also be signs of Fanconi anemia. Rarely, a young child with FA will develop myelodysplastic syndrome or leukemia.
Signs and Symptoms During Young Adulthood
Sometimes people with Fanconi anemia do not show signs or symptoms of the disease during childhood. Instead, they present with myelodysplastic syndrome, leukemia or solid tumors as young adults.
Fanconi Anemia Diagnosis
Pediatric hematologists who specialize in Fanconi anemia can provide a diagnosis by:
- Doing a complete physical
- Learning about the person’s medical history and the family’s medical history
- Asking about current symptoms
- Performing blood tests to check for low white blood cell, red blood cell and platelet counts, and other problems
Doctors use specialized tests including genetic tests to confirm a diagnosis of FA. The gold-standard specialized test is called chromosome breakage test. Genetic tests can help pinpoint which changed gene is causing the disease. A doctor may order this type of test if a person:
- Shows signs and symptoms that could be related to FA
- Has a brother or sister who has been diagnosed with FA
Genetic test results can sometime influence a child’s treatment plan. For example, changes in a certain FA gene shows that a person is at higher risk for certain cancers very early in life (example FANC D1). If this is the case, the care team will monitor the patient closely. They will be looking for any early signs of cancer.
Fanconi Anemia Treatment
Children with Fanconi anemia need life-long care and monitoring. The care team will develop a personalized treatment plan. This will help find and treat problems that happen due to the condition. This will include a yearly check-up, blood tests and bone marrow testing (usually starting at 2 years of age) to see how FA is affecting the child’s bone marrow. The doctor also may recommend testing the function of vital organs (such as the kidneys and heart) to check for any problems.
Commonly used therapies for bone marrow failure related to FA include:
- Transfusion support (example: blood and platelet transfusion)
- White blood cell count support with a growth factor called granulocyte-colony stimulating factor (G-CSF).
- Androgen, a type of male hormone. Androgen may increase the production of red blood cells and, often, platelets. This type of therapy works for some people but not for everyone. Androgens can steady blood counts or improve blood count long term. It is not a cure. It can cause unwanted side effects.
These options are used temporarily until the care team develops more definitive treatment plans.
The only potentially curative therapy currently available is bone marrow transplantation (BMT). BMT is a procedure that destroys unhealthy stem cells in a patient’s bone marrow. The unhealthy stem cells are replaced with healthy blood-forming stem cells from a donor. The care team may recommend BMT when a child’s bone marrow failure is becoming severe enough to require transfusions. They may also recommend BMT when the child develops myelodysplastic syndrome or leukemia. This procedure is also called an allogeneic hematopoietic stem cell transplant (HSCT).
BMT can cure blood problems related to Fanconi anemia. It also can get rid of the child’s risk of getting myelodysplastic syndrome and leukemia related to Fanconi anemia. If those conditions have already developed, BMT can treat them.
Bone marrow transplants for people with Fanconi anemia are complex and specialized. They should take place at a specialized center where experts have in-depth knowledge and expertise in this area of medicine.
Even after a successful BMT, patients with Fanconi anemia are at increased risk of developing solid tumors of head and neck region and genital system. People with Fanconi anemia should have lifelong follow-up from their care team.
Other specialized therapies and surgeries for people with FA
People with FA may need other types of care, such as:
- Heart surgery to correct heart defects
- Orthopedic surgery to correct skeletal problems
- Therapies for gastrointestinal, kidney or other problems related to Fanconi anemia.
- Hormone therapy to treat poor growth, thyroid conditions and diabetes
Educational and emotional support from the treatment team help patients and families understand and cope with FA. Genetic counseling can also help.
Fanconi Anemia Resources
Researchers are studying Fanconi anemia to better understand the disease. They are working to develop new treatments. The Fanconi Anemia Comprehensive Care Center at Cincinnati Children’s offers new research and experimental therapies for children and young adults with Fanconi anemia.
To learn more about Fanconi anemia, visit the Fanconi Anemia Research Fund. The organization provides family support, medical information and care guidelines.