What Is Fanconi Anemia?

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Fanconi anemia (FA) is a rare genetic disease, affecting 1 in 160,000 people. The condition leads to gradual bone marrow failure in about 90% of people affected. Bone marrow is the spongy material inside the bones that makes platelets, red blood cells, and white blood cells. These cells are important to good health. 

Fanconi anemia is a condition that affects many parts of the body, often causing physical abnormalities, like malformed thumbs or forearms, and organ defects, such as absent kidneys and heart defects. It also increases the chance of getting some cancers, like leukemia (cancers of the blood) and myelodysplasia (bone marrow diseases). 

This article will review common symptoms of FA, as well as causes and risk factors, how the condition is diagnosed, and treatment options.

Cancer patient looking out

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What Are Symptoms of Fanconi Anemia?

Fanconi anemia (FA) is a rare genetic disorder that causes gradual bone marrow failure. Most often, signs and symptoms of Fanconi anemia appear at birth or early in childhood, between 5 and 10 years of age.

As bone marrow loses its ability to make blood cells and platelets, it can lead to low blood cell counts—a condition known as aplastic anemia. Low blood cell counts and bone marrow failure may lead to the following symptoms:

  • Extreme fatigue
  • Frequent infections
  • Easy bruising
  • Nose or gum bleeding

These symptoms are due to low numbers of red blood cells, white blood cells, or platelets. About 75% of children with FA also are born with one or more of the following physical characteristics:

  • Café au lait spots (light-brown birthmarks)
  • Short stature
  • Thumb and arm abnormalities (missing, misshapen, or extra thumbs or an incompletely developed/missing forearm bone)
  • Low birth weight
  • Small head or eyes
  • Abnormalities of the kidneys, genitals, gastrointestinal tract, heart, and central nervous system
  • Curved spine (scoliosis)
  • Deafness
  • Internal bleeding
  • Congenital (at birth) heart defects

About 60% will have one of the following nonphysical symptoms:

  • Learning disabilities (problems) or intellectual disabilities
  • Poor appetite
  • Delays in growth and puberty

Causes and Risk Factors

Fanconi anemia (FA) is a hereditary condition that is passed down from generation to generation Although the exact cause of FA is unclear, defects in at least 18 genes that provide instructions to help the body repair certain types of DNA damage have been linked to the disease.

An estimated 80%–90% of FA cases are linked to mutations in one of three genes: FANCA, FANCC, and FANCG.

Most cases are considered autosomal recessive, which means a child must receive two copies of the mutated gene—one from each biological parent—to have the disorder. People with one mutated gene will be a carrier (able to pass the mutated gene on to their children) but usually won't develop symptoms.

FA is more common among people of Ashkenazi Jewish descent, the Roma population of Spain, and Black South Africans than the general population.

How Fanconi Anemia Is Diagnosed

A diagnosis of Fanconi anemia (FA) is made based on a thorough physical exam, a detailed patient history, and a variety of specialized blood tests.

The most common test for FA is a blood test called a chromosomal breakage test. This test looks for DNA damage that is characteristic of FA. This test can be done in utero (before the child is born) if FA is a concern.

In patients presenting with symptoms, a healthcare provider will take your medical history, ask about your symptoms and any family history with similar disorders, and do a focused physical exam looking for dark spots called café au lait spots and any physical abnormalities. They will also order a complete blood cell count (CBC).

If FA is suspected, a healthcare provider may also request an electrocardiogram (EKG), which can detect heart rhythm abnormalities that may be indicative of a heart defect. Computed tomography (CT) scan or magnetic resonance imaging (MRI) may show physical or organ defects, including:

  • Thumb and arm anomalies, such as an extra or misshaped or missing thumbs and fingers or an incompletely developed or missing radius (one of the forearm bones)
  • Skeletal anomalies of the hips, spine, or ribs
  • Structural kidney defects or absent kidneys
  • Small reproductive organs in males
  • Defects in tissues separating the heart

The wide variability of symptoms among people with FA makes an accurate diagnosis based on clinical manifestations alone difficult.

To establish the extent of disease in an individual diagnosed with FA, the following evaluations are recommended as needed:

  • Ultrasound examination of the kidneys and urinary tract
  • Formal hearing test
  • Developmental assessment
  • Referral to necessary specialists as needed 

How the Condition Is Treated

The treatment of Fanconi anemia (FA) is based on how low or abnormal the blood counts are and the age of the patient.

Treatment is also geared toward managing your symptoms, which may require the input of multiple specialists, including pediatricians, surgeons, cardiologists (heart specialists), nephrologists (kidney specialists), urologists (urinary tract specialists), gastroenterologists (GI tract specialists), hematologists (blood specialists), audiologists and otolaryngologists (specialists who assess and treat hearing problems), ophthalmologists (eye specialists), and other healthcare professionals.

The following short-term strategies to monitor the disease and control symptoms are essential to the treatment of FA:

  • Regular blood-count checks
  • A yearly bone marrow test
  • Screening for tumors and cancer
  • Antibiotic treatment as needed (to fight infections)
  • Blood transfusion as needed (to increase blood cell count)

Longer-term treatment can include:

  • Blood and bone marrow stem cell transplant
  • Surgery to correct birth defects
  • Gene therapy
  • Genetic testing and counseling

The following long-term treatments are also commonly used in those with FA to increase blood cell counts:

  • Use of androgens (male hormones): Androgens improve the blood counts in approximately 50% of individuals with FA. The earliest response is seen in red cells, with an increase in hemoglobin generally occurring within the first month or two of treatment. Responses in the white cell count and platelet count are variable.
  • Hematopoietic growth factors: Treating patients with granulocyte colony-stimulating factor (G-CSF) has been shown to improve the count of neutrophils (a type of white blood cell) in some individuals, but it is less commonly used than androgen therapy.
  • Hematopoietic stem cell transplantation (HSCT): This treatment consists of harvesting and placing donor stem cells from a peripheral (outside) source such as bone marrow or blood or cord blood into the bone marrow. It is the only curative therapy for the hematologic (blood-based) manifestations of FA. 

What's the Prognosis?

A better understanding of the genetic and molecular causes of FA and improved clinical management has transformed the condition from a deadly disease to a chronic condition that can be well managed with lifelong multidisciplinary treatment.

Although the average lifespan for people with the disorder is between 20 and 30 years old, some patients are living into their 30s, 40s, and 50s.

A person's prognosis largely depends on the progression of their bone marrow failure and whether they go on to develop aplastic anemia. It's also important to monitor for the presence of related cancers such as acute myeloid leukemia and myelodysplasia, so they can be caught and treated as early as possible.

Blood and bone marrow stem cell transplant have proven to be an effective treatment, but the risk of developing solid tumors increases as people with Fanconi anemia get older, so lifelong screening for these cancers is needed.

Summary

Fanconi anemia (FA) is a rare genetic condition that is passed on from generation to generation. People with this disorder usually inherit a mutated gene from each of their parents. They may be born with physical abnormalities, such as an extra or misshaped or missing thumbs and fingers, an incompletely developed or malformed forearm, or a heart defect.

Most cases of FA are diagnosed before or shortly after birth. In some cases, symptoms may develop later, usually between the ages of 5 and 10. Symptoms may include fatigue, easy bruising, and bleeding from the gum, due to low blood cell counts.

Diagnosis usually involves genetic testing and other blood tests. Imaging studies may also be used. Treating FA is a lifelong battle that requires careful monitor. Fortunately, treatment options have advanced and many people with FA are able to have a fulfilling life.

A Word From Verywell

The treatment of Fanconi anemia has improved immensely due to advances in modern medicine, but it still requires lifelong monitoring, including checking blood counts every three months and occasional bone marrow examination.

Lifestyle changes such as avoiding certain activities that can cause bruising and bleeding if you have low levels of platelets and avoiding tobacco and alcohol to limit your cancer risk are encouraged early in life and often become natural lifelong habits for many people with FA. 

9 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Shamard Charles, MD, MPH
Shamard Charles, MD, MPH is a public health physician and journalist. He has held positions with major news networks like NBC reporting on health policy, public health initiatives, diversity in medicine, and new developments in health care research and medical treatments.