There are multiple types of Fanconi anemia (FA). Carrier screening is typically offered for Fanconi anemia Type C (FA-C), which is more common in the Ashkenazi Jewish population than in other groups.

Fanconi anemia is a disease characterized by bone marrow failure, causing reduced production of blood cells, which results in extreme fatigue, frequent infections, and easy bruising and bleeding, and an increased risk for leukemia and other cancers.

People with FA may also have physical findings, which are highly variable, and may include short stature, upper limb differences, kidney, cardiac, and gastrointestinal problems, brown-pigmented spots on the skin, hearing loss, and developmental delay.

Cancer is difficult to treat in people with Fanconi Anemia because they are often more sensitive to the toxic effects of chemotherapy and radiation. People with FA who have had successful bone marrow transplants still remain at increased risk for other cancers.

The major cause of death in individuals with FA is bone marrow failure, followed by leukemia. The median survival rate has improved in the recent decade from 20 years to greater than 30 years of age.

One in 89 Ashkenazi Jewish individuals is a carrier of Fanconi anemia Type C.

How Is Fanconi Anemia Inherited?

The cells in our body typically contain 46 chromosomes. Each chromosome is a package that holds hundreds of genes. These genes contain the all of the blueprints for our growth and development; they are the instructions that make us who we are. All of our chromosomes (and the genes that are located on these chromosomes) come in pairs. We inherit one chromosome of each pair from our mother and the other chromosome of the pair from our father.

 
click to enlarge

When there is a change in a gene (called a mutation) the instructions it contains are no longer correct and the gene cannot carry out its function. Individuals with FA-C have two copies of a mutation, one copy inherited from each parent. Neither gene in the pair is working correctly, which causes the symptoms of the disease.

A carrier of FA-C is a person who has a mutation in one gene of the pair. Carriers are unaffected with the disease because the properly working gene is able to compensate for the gene that contains the mutation.

When two parents are carriers of FA-C:

• there is a 1 in 4 (25%) chance of having a child with FA-C,
• there is a 1 in 2 (50%) chance of having a child who is an unaffected carrier like the parents,
• and, there is 1 in 4 (25%) chance of having a child who is unaffected and is not carrier.

When one parent is a carrier of FA-C and the other parent is not a carrier, they are not at increased risk to have a child with FA-C. Instead, there is a 1 in 2 (50%) chance of having a child with is an unaffected carrier like the one parent.

What This Test Tells You

This test tells whether you are a carrier of Fanconi anemia Type C. It looks for the two gene mutations that account for 99% of mutations that cause FA-C in people of Ashkenazi Jewish descent. These mutations are called IVS4+4A>T and 322delG.

There are at least 11 genes that have been found which are associated with FA. In only one of these genes, FANCC, are mutations found more commonly in Ashkenazi Jewish people.

How Testing Works

Testing with DNA Direct is quick, convenient, and can be done in the privacy of your home. It can also be anonymous if you wish. How to order online and consult with our genetic experts: DNA Direct's Expert Services