BCR-ABL Quantitative

Why get tested? A BCR-ABL test is most often used to diagnose or rule out chronic myeloid leukemia (CML) or a specific form of acute lymphoblastic leukemia (ALL) called Ph-positive ALL. Ph-positive means a Philadelphia chromosome was found. The test is not used to diagnose other types of leukemia.

The test may also be used to:

• See if cancer treatment is effective.
• See if a patient has developed a resistance to certain treatment. That means a treatment that used to be effective is no longer working.

Also known as: BCR-ABL1, BCR-ABL1 fusion, Philadelphia chromosome

Description:
A BCR-ABL genetic test looks for a genetic mutation (change) on a specific chromosome.
Chromosomes are the parts of your cells that contain your genes. Genes are parts of DNA passed down from your mother and father. They carry information that determines your unique traits, such as height and eye color.
People normally have 46 chromosomes, divided into 23 pairs, in each cell. One of each pair of chromosomes comes from your mother, and the other pair comes from your father.

BCR-ABL is a mutation that is formed by the combination of two genes, known as BCR and ABL. It's sometimes called a fusion gene.

• The BCR gene is normally on chromosome number 22.
• The ABL gene is normally on chromosome number 9.
• The BCR-ABL mutation happens when pieces of BCR and ABL genes break off and switch places.
• The mutation shows up on chromosome 22, where the piece of chromosome 9 has attached itself.
• The mutated chromosome 22 is called the Philadelphia chromosome because that's the city where researchers first discovered it.
• The BCR-ABL gene is not the type of mutation that is inherited from your parents. It is a type of somatic mutation, which means you are not born with it. You get it later in life.

The BCR-ABL gene shows up in patients with certain types of leukemia, a cancer of the bone marrow and white blood cells. BCR-ABL is found in almost all patients with a type of leukemia called chronic myeloid leukemia (CML). Another name for CML is chronic myelogenous leukemia. Both names refer to the same disease.

The BCR-ABL gene is also found in some patients with a form of acute lymphoblastic leukemia (ALL) and rarely in patients with acute myelogenous leukemia (AML).

Certain cancer medicines are especially effective in treating leukemia patients with the BCR-ABL gene mutation. These medicines also have fewer side effects than other cancer treatments. The same medicines are not effective in treating different types of leukemia or other cancers.

Reasons for referral:
You may need a BCR-ABL test if you have symptoms of chronic myeloid leukemia (CML) or Ph-positive acute lymphoblastic leukemia (ALL). These include:

• Fatigue
• Fever
• Weight loss
• Night sweats (excessive sweating while sleeping)
• Joint or bone pain

Some people with CML or Ph-positive ALL have no symptoms, or very mild symptoms, especially in the early stages of the disease. So your health care provider may order this test if a complete blood count or other blood test showed results that were not normal. You should also let your provider know if you have any symptoms that concern you. CML and Ph-positive ALL are easier to treat when found early.

You may also need this test if you are currently being treated for CML or Ph-positive ALL. The test can help your provider see if your treatment is working.

Sample Requirement: Whole blood/ Bone Marrow

Test Preparation: No test preparation is needed.

Test Done by: 3500Dx Genetic Analyzer