Fanconi Anemia

Overview

Fanconi anemia is a rare inherited disorder that affects how the body repairs its DNA. This faulty DNA repair has wide-ranging effects, but it most notably impairs the bone marrow, the tissue that makes blood cells. Over time, many people with Fanconi anemia develop bone marrow failure, in which the marrow cannot make enough red blood cells, white blood cells, and platelets.

Despite its name, Fanconi anemia involves more than just anemia. It is also associated with a range of physical differences present at birth and a significantly higher risk of certain cancers, including blood cancers and some solid tumors. It is usually diagnosed in childhood, though milder forms may be recognized later. Care involves managing blood counts, watching for cancer, and treating complications.

Symptoms

Signs vary widely from person to person, even within the same family. They may include:

• Low blood counts, causing fatigue and paleness from anemia, frequent infections from low white cells, and easy bruising or bleeding from low platelets.
• Physical differences present at birth, such as differences in the thumbs or arms, short stature, kidney or heart differences, and skin pigment changes (café-au-lait spots).
• Small head or eyes in some cases.
• Developmental or learning differences in some children.
• Hearing differences.

Some people have many features while others have few, so the diagnosis is not always obvious from appearance alone.

Causes

Fanconi anemia is caused by inherited changes (mutations) in any of several genes involved in repairing DNA. Key points include:

• The faulty genes leave cells unable to fix certain kinds of DNA damage properly.
• This leads to the death of blood-forming cells over time, causing bone marrow failure, and increases the risk that cells become cancerous.
• It is usually inherited in an autosomal recessive pattern, meaning a child must inherit a changed gene from both parents, who are typically unaffected carriers.

Because both parents usually carry the gene without symptoms, families may have no prior knowledge of the condition before a child is diagnosed.

Risk Factors

The main risk factor is genetic inheritance. Risk is higher when:

• Both parents carry a changed copy of one of the genes that cause Fanconi anemia.
• There is a family history of the disorder.
• Parents are from certain populations where particular gene changes are more common.
• Parents are closely related, which increases the chance of inheriting the same gene change from both sides.

Genetic counseling can help families understand their risk.

Diagnosis

Diagnosis often begins when a child has low blood counts, physical differences, or both. Tests may include:

• Blood tests showing low red cells, white cells, or platelets.
• A chromosome breakage test, a specialized laboratory test in which cells are exposed to certain chemicals; cells from people with Fanconi anemia show characteristic excess chromosome breakage. This is a key diagnostic test.
• Genetic testing to identify the specific gene change.
• Bone marrow examination to assess marrow function.
• Evaluations of the heart, kidneys, hearing, and other systems for associated differences.

Treatment

There is no simple cure, and care is tailored to each person. Approaches include:

• Stem cell (bone marrow) transplant, which can replace the failing marrow and is the main treatment for bone marrow failure. It does not prevent the higher risk of solid cancers, which still requires monitoring.
• Medications in some cases to stimulate blood cell production for a time.
• Blood transfusions to manage low counts.
• Treatment of infections and supportive care.
• Regular cancer screening, since people with Fanconi anemia are at higher risk of leukemia and certain solid tumors, especially head, neck, and gynecologic cancers.
• Care from a team of specialists and surgery for some physical differences.

Lifelong monitoring is important to detect and treat complications early.

Prevention

Because Fanconi anemia is inherited, it cannot be prevented in the usual sense, but families can take informed steps:

• Genetic counseling for families with a history of the disorder or known carriers.
• Carrier testing for prospective parents who may be at risk.
• For people diagnosed with the condition, avoiding tobacco and excess alcohol and following recommended cancer screening can help reduce and detect complications.
• Regular medical follow-up to catch problems early.

When to See a Doctor

See a doctor if a child has unexplained fatigue, paleness, frequent infections, easy bruising or bleeding, or physical differences such as thumb or arm differences and short stature, especially if there is a family history. Early evaluation allows for monitoring and timely treatment.

Seek urgent care for serious bleeding that will not stop, signs of a serious infection such as high fever in someone with low blood counts, or severe symptoms. People with Fanconi anemia should keep all recommended follow-up and cancer screening appointments.

Related Topics

Frequently Asked Questions

References

1. MedlinePlus, U.S. National Library of Medicine.
2. National Cancer Institute (NCI).
3. Genetic and Rare Diseases Information Center (GARD), NIH.
4. Mayo Clinic.