Fanconi's anemia

Definition

Fanconi's anemia is disease passed down through families (inherited) that mainly affects the bone marrow. It results in decreased production of all types of blood cells.

Fanconi's anemia is different from Fanconi syndrome, a rare kidney disorder.

Alternative Names

Anemia - Fanconi's

Causes, incidence, and risk factors

Fanconi's anemia is due to an abnormal gene that prevents cells from fixing damaged DNA or removing cell damaging substances called oxygen-free radicals.

To inherit Fanconi's anemia, a person must get one copy of the abnormal gene from each parent.

The condition is usually diagnosed in children between 2 and 15 years old.

Symptoms

Person's with Fanconi's anemia have lower-than-normal numbers of white blood cells, red blood cells, and platelets (cells that help the blood clot).

Not enough white blood cells can lead to infections. A lack of red blood cells may result in fatigue (anemia).

A lower-than-normal amount of platelets may lead to excess bleeding.

Most people with Fanconi's anemia have these types of symptoms:

• Abnormal heart, lungs, and digestive tract
• Bone problems (especially the hips, spine or ribs, can causes a curved spine (scoliosis)
• Changes in the color of the skin, such as:
  • Darkened areas of the skin
  • Vitiligo
• Deafness due to abnormal ears
• Eye or eyelid problems
• Kidney(s) that did not form correctly
• Problems with the arms and hands, such as:
  • Missing, extra or misshapen thumbs
  • Problems of the hands and the bone in the lower arm
  • Small or missing bone in the forearm
• Short height
• Small head
• Small testicles and genital changes

Other possible symptoms:

• Failure to thrive
• Learning disability
• Low birth weight
• Mental retardation

Signs and tests

Common tests for Fanconi's anemia include:

• Bone marrow biopsy
• Complete blood count (CBC)
• Developmental tests
• Drugs added to a blood sample to check for damage to chromosomes
• Hand x-ray and other imaging studies (CT scan, MRI)
• Hearing test
• HLA tissue typing (to find matching bone-marrow donors)
• Ultrasound of the kidneys

Pregnant women may haveamniocentesis or chorionic villous sampling to diagnose the condition in their unborn child.

Treatment

Patients with mild to moderate blood cell changes who do not need a transfusion may only need regular check-ups, frequent blood count checks, and yearly bone marrow exams. The health care provider will closely monitor the person for other cancers, usually leukemia or lymphoma.

Medicines called growth factors (such as erythropoietin, G-CSF, and GM-CSF) can improve blood counts for a short while.

A bone marrow transplant can cure the blood count problems of Fanconi's anemia. (The best donor is a brother or sister whose tissue type matches the patient.)

Persons who have had a successful bone marrow transplant still need regular check-ups because of the risk for additional cancers.

Hormone therapy combined with low doses of steroids (such as hydrocortisone or prednisone) is prescribed to those who do not have a bone marrow donor. Most patients respond to hormone therapy. But everyone with the disorder will quickly get worse when the drugs are stopped. In most cases, these drugs eventually stop working.

Additional treatments may include:

• Antibiotics (possibly given through a vein) to treat low white blood cell counts and infections
• Blood transfusions to treat symptoms due to low blood counts

Most people with this condition visit a blood disorder specialist (hematologist), a doctor who treats diseases related to glands (endocrinologist), and an eye doctor (ophthalmologist) regularly. They also may see a bone doctor (orthopedist), gynecologist, or kidney disease specialist (nephrologist).

Expectations (prognosis)

The survival rates vary from person to person. The outlook is poor in those with low blood counts. New and improved treatments, such as bone marrow transplants, have likely improved survival.

Persons with Fanconi's anemia are more likely to develop several types of cancers, including leukemia, myelodysplastic syndrome, and liver cancer.

Women with Fanconi's anemia who become pregnant should be watched carefully by a doctor. Such women often need transfusions throughout pregnancy.

Men with Fanconi's anemia have decreased fertility.

Prevention

Families with this condition can have genetic counseling to better understand their risk.

Vaccination can prevent certain complications, including pneumococcal pneumonia, hepatitis, and varicella infections.

Persons with Fanconi's anemia should avoid cancer-causing substances (carcinogens) and have regular check-ups to screen for cancer.

References

Castro-Malaspina H, O’Reilly RJ. Aplastic anemia and related disorders. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 171.