"Rhabdoid Tumor Predisposition" – What Is It?
Rhabdoid tumor predisposition syndrome (RTPS) is a rare genetic, i.e., hereditary, disease that can lead to highly aggressive brain tumors (so-called atypical teratoid/rhabdoid tumors) and malignant tumors of other tissues, mostly the kidneys (so-called malignant rhabdoid tumors), even in young children. In addition, other tumors or diseases can also occur as part of RTPS.
How Is "Rhabdoid Tumor Predisposition" Diagnosed?
RTPS is a genetic disease based on mutations, i.e., changes to the genetic material in certain genes. In this case, the genes involved are SMARCB1 and SMARCA4. Suppose a child suffers from an atypical teratoid/rhabdoid tumor (a very aggressive brain tumor) or a malignant rhabdoid tumor (a malignant tumor of other tissues). In that case, whether there is a mutation in one of the two genes should be investigated. The detection of such a mutation could confirm the diagnosis of RTPS.
As this is a hereditary disease, blood-related family members of a person with a detected mutation in the SMARCB1 or SMARCA4 genes should also be genetically tested.
What Is the Risk of Cancer?
The two most common clinical features of RTPS are rhabdoid tumors. These malignant tumors can occur in the brain and are then called “atypical teratoid/rhabdoid tumors” (AT/RT). Still, they can also develop in other tissues and are then called “malignant rhabdoid tumors” (MRT). These MRTs are most frequently found in the kidneys. Most AT/RT and MRT occur up to the age of three, although they can also occur later. Mutations in both genes(SMARCB1 or SMARCA4) can lead to AT/RT and MRT development.
In female patients who are carriers of a SMARCA4 mutation, ovarian cancer (small cell ovarian carcinoma of the hypercalcemic type) may also occur in adolescence or adulthood.
Furthermore, RTPS can lead to the development of other diseases, which are listed below:
- Schwannomatosis with a mutation in SMARCB1
- Plexus carcinoma (malignant brain tumor) with a mutation in SMARCB1
- Medulloblastoma (malignant tumor of the cerebellum) with a mutation in SMARCB1
- Multiple meningiomas (mostly benign tumors) with a mutation in SMARCB1
- Nicolaides-Baraitser syndrome with mutation in SMARCB1
- Coffin-Siris syndrome with mutation in SMARCB1, SMARCA4
- Malignant peripheral nerve sheath tumor with mutation in SMARCB1
It is not uncommon for those affected to develop several of the above-mentioned tumors in parallel.
Exact figures on the incidence of the disease are not yet known. It is also not yet clear how often a genetic change leads to the occurrence of tumors or other diseases. However, it has been observed that the risk of developing atypical teratoid/rhabdoid tumors is significantly lower in the presence of a mutation in the SMARCA4 gene than in the presence of a mutation in the SMARCB1 gene.
What Is Known About the Development of "Rhabdoid Tumor Predisposition "?
Rhabdoid tumor predisposition syndrome is a genetic, i.e., hereditary, disease caused by mutations in one of the two genes, SMARCB1 or SMARCA4. These mutations mean the DNA carrying our genetic information can no longer be correctly “translated” and repaired in the body’s cells. As a result, malformations, tumors, and other diseases develop.
Around 35% of patients with rhabdoid tumors have inherited the underlying genetic change in one of the above-mentioned genes from their parents; the inheritance is autosomal dominant. Therefore, it is advisable to examine all blood-related family members of an affected person regarding these genetic changes.
Is There Any Form of Treatment Available?
The therapy depends on the disease in question and the existing symptoms.
Depending on the disease, it consists of surgical treatment, which may be combined with chemotherapy and/or radiotherapy.
Five years after the diagnosis of RT/AT or MRI, around 10-30% of patients are still alive. For patients with ovarian cancer (small cell ovarian cancer of the hypercalcemic type), the figure is around 33%.
Please ask your attending physician whether any open clinical trials suit you.
Diagnosis of " Rhabdoid Tumor Predisposition" What's Next?
If you have been diagnosed with this cancer predisposition syndrome, it is important to see a specialist. The following section explains whether cancer screening tests or other measures are needed and how they should be carried out. We also give you some valuable tips on what you can do yourself. If you have any questions, please do not hesitate to contact us or your doctor.
Diagnosis of " Rhabdoid Tumor Predisposition" What's Next?
If you have been diagnosed with this cancer predisposition syndrome, it is important to see a specialist. The following section explains whether cancer screening tests or other measures are needed and how they should be carried out. We also give you some valuable tips on what you can do yourself. If you have any questions, please do not hesitate to contact us or your doctor.
Medical Measures for Early Detection
The procedure for early detection also depends on the gene mutation, i.e., a distinction must be made as to whether the genetic change is present in SMARCB1 or SMARCA4. There are no standardized recommendations to date, but the American Association for Cancer Research suggests the following procedure:
Carrier of a SMARCB1 Mutation
- Detailed physical examination every 3-4 months
- Immediate pediatric examination in case of new medical problems
- Ultrasound of the abdomen and pelvis every 3-4 months
- Only perform a blood test if ultrasound is not available
- Annual MRI of the head
- Annual whole-body MRI
Carrier of a SMARCA4 Mutation
- Abdominal ultrasound every 6 months for younger women
- Prophylactic removal of the ovaries in older women
Rhabdoid Tumor Predisposition – What You Can Do Yourself
You Should Pay Attention to This
Neurological abnormalities can be symptoms of AT/RT. In infants and young children, these are usually drowsiness and vomiting. Older children may also have other symptoms such as headaches, hemiplegia or tilting of the head, double vision, or facial paralysis. If you observe one or more of these signs in your child, you should urgently consult a doctor.
Further Information
Unfortunately, we are not yet aware of any support groups for patients with rhabdoid tumor predisposition syndrome (RTPS). As soon as we have new information, we will add it here. However, patients can also register for the CPS registry at any time or have this done by their doctors in charge.
Any further questions?
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