What are Robertsonian translocation 15;21 and ring chromosome 21?

Robertsonian translocation 15;21 and ring chromosome 21 are very rare genetic changes that result in a greatly increased risk of developing acute lymphoblastic leukemia (ALL), which involves a special subtype called iAMP21-ALL. Any association with other forms of ALL or other tumor diseases is unknown to date.

How is the diagnose made?

Genetic Diagnostics

The diagnosis of Robertsonian translocation 15;21 is confirmed by detection of a fusion between chromosomes 15 and 21 in the chromosome analysis or by fluorescence in situ hybridization (FISH). The presence of ring chromosome 21 can also be confirmed with this method.

What is the risk of cancer?

The risk of developing iAMP21-ALL is approximately 2700 times greater in patients with Robertsonian translocation 15;21 compared to the general population. There is an increased risk of iAMP21-ALL occurring with ring chromosome 21 as well. iAMP21-ALL generally occurs later (at the age of 9 years on average) than other subtypes of pediatric ALL (at the age of 2-5 years on average). In addition, it is also characteristic for there to be low numbers of white blood cells.

Any association with other forms of ALL or other tumor diseases is unknown to date.

What causes Robertsonian translocation 15;21 and ring chromosome 21?

Robertsonian translocation 15;21 and ring chromosome 21 involve structural changes in our genetic material. Robertsonian translocation 15;21 is characterized by the linking of chromosomes 15 and 21 – normally separate – to form one chromosome. With ring chromosome 21, the ends of one chromosome (in this case, chromosome 21) fuse, resulting in a ring-shaped chromosome. These structural changes may cause leukemia to develop.

Is there a treatment?

During treatment, it is invariably helpful to have a discussion with the ALL principal investigator. This is generally handled by your treatment team.

Surveillance Recommendations for the Early Detection of Cancer

Surveillance Recommendations

Since Robertsonian translocation 15;21 and ring chromosome 21 are very rare genetic changes, there is not yet sufficient data available to provide standardized recommendations for early detection. As with other leukemia predisposition syndromes, the following examinations should be conducted on a regular basis:

  • Clinical examinations

  • Complete blood count once a year

  • Bone marrow puncture only with unstable blood values / clinically suspected leukemia

Self-Care and Support

What should I pay special attention to?

You should consult a doctor as soon as you notice any frequent infections, increased or hard-to-stop bleeding (e.g. long-lasting or frequent nose bleeds), increased bruising, fatigue or if you feel sick, have a fever, enlarged lymph nodes, or suffer from bone pain. If you develop new symptoms or complaints, they should likewise be evaluated as soon as possible.

Support Groups and Additional Information

Unfortunately, we are as yet unaware of any existing support groups for patients with Robertsonian translocation 15;21 or ring chromosome 21. We will add new information as it becomes available.