Fanconi's anemia Health Article

Definition

Fanconi's anemia is an inherited disease that mainly affects the bone marrow. It results in decreased production of all types of blood cells. Fanconi's anemia is different from Fanconi's syndrome, a rare kidney disorder in which a person loses nutrients through the urine.

Alternative Names

Anemia - Fanconi's; FA

Causes, incidence, and risk factors

To inherit Fanconi's anemia, a person must get one copy of the abnormal gene from each parent. The condition occurs in all racial and ethnic groups. It is usually diagnosed when a person is between 2 and 15 years old.

The disease is caused by a genetic defect. This defect prevents cells from fixing damaged DNA or removing toxic substances called oxygen-free radicals that damage cells. People with certain birth defects or who develop low blood counts may have this disease.

Symptoms

The lack of white blood cells can lead to infections. Not having enough of the cells in blood (platelets) that cause clotting may lead to excess bleeding. A lack of red blood cells may result in fatigue (anemia).

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

• Skin pigment change (darkened areas of the skin, cafe-au-lait spots, vitiligo)
• Short height
• Upper limb problems (missing, extra or misshapen thumbs; small or missing radius bone in the forearm; problems of the hands and the forearm bone in the lower arm)
• Small testicles, genital changes
• Abnormal bones (abnormalities of the hip, spine or rib; curved spine (scoliosis); small head)
• Abnormal eye/eyelid
• Malformed kidney
• Abnormal ears/deafness
• Abnormal hip, leg, and toe
• Abnormal digestive tract/heart and lungs

Other possible symptoms:

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

Signs and tests

Common tests for Fanconi's anemia include:

• Complete blood count (CBC)
• Bone marrow biopsy
• Drugs added to a blood sample to check for damage to chromosomes (clastogenic stress-induced chromosomal breakage analysis)
• HLA tissue typing (to find matching bone-marrow donors)
• Hand x-ray and other imaging studies (CT scan, MRI)
• Hearing test
• Developmental tests
• Ultrasound of the kidneys
• Amniocentesis or chorionic villous sampling (in pregnancy)

Treatment

If the blood cell changes are mild to moderate and a transfusion isn't needed, many doctors recommend a period of watching with frequent blood count checks and yearly bone marrow exams. Doctors will also watch for secondary cancers. In the short term, taking growth factors (such as erythropoietin, G-CSF, and GM-CSF) can improve blood counts. Researchers are studying other growth factors to stimulate platelets.

A bone marrow transplant can cure the blood count problems of Fanconi's anemia. A HLA matched sibling is the best donor source. Other sources are blood cells from the umbilical cord and bone marrow from an unrelated person. A bone marrow transplant is very effective. Although there can be side effects from this treatment, the care of people with Fanconi's tends to improve during the transplant. The success rate is high for people who have a donor.

Even though a successful bone marrow transplant can cure the bone marrow problems from Fanconi's anemia, people with this condition are at risk for other cancers and must be regularly checked by a doctor.

Before bone marrow transplantation, the standard treatment was hormone therapy combined with low doses of steroids (hydrocortisone, prednisone). Doctors use this approach on people who do not have a bone marrow donor. Most patients respond to hormone therapy. But everyone with the disorder will quickly relapse when the drug is stopped. In most cases, these drugs eventually stop working.

Transfusions or antibiotics can treat symptoms due to low blood counts, such as bleeding, infections, or anemia that causes symptoms (fatigue, shortness of breath, chest pain, dizziness). People with low amounts of white blood cells called neutrophils who develop a fever are usually treated with antibiotics through a vein.

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) as needed.