What Are Translocations?

Translocations are chromosomal abnormalities that involve the exchange of genetic material between two chromosomes. They can occur between any two chromosomes, but some translocations are more common than others. For example, the translocation between chromosomes 9 and 22 is associated with chronic myeloid leukemia (CML).

Translocations can be classified into two main types: balanced and unbalanced. Balanced translocations do not result in any loss or gain of genetic material. They can occur when two chromosomes break and then exchange pieces of DNA. Unbalanced translocations, on the other hand, result in the loss or gain of genetic material. They can occur when a piece of one chromosome is translocated to another chromosome without a corresponding exchange of DNA.

Balanced translocations are usually harmless and do not cause any health problems. However, unbalanced translocations can lead to a variety of medical conditions, including cancer, birth defects, and intellectual disabilities.

The risk of developing a translocation-related medical condition depends on the specific translocation that occurs. Some translocations are associated with a high risk of medical problems, while others are associated with a low risk.

Translocations can be diagnosed using a variety of cytogenetic techniques. These techniques can identify the specific chromosomes involved in the translocation and determine whether the translocation is balanced or unbalanced.

There is no cure for translocations, but some of the medical conditions that they can cause can be treated. For example, CML can be treated with imatinib mesylate (Gleevec), a drug that targets the BCR-ABL1 fusion gene that is formed as a result of the t(9;22) translocation.