How is a retinoblastoma inherited?
There are two different types of retinoblastoma. On the one hand the sporadic (occasionally occurring) retinoblastoma, which occurs in 40% of cases. This leads to different changes (mutations) in the affected gene and finally to the formation of a retinoblastoma.
This usually occurs only on one side and is not inherited. Inherited retinoblastoma is the hereditary form, which occurs in 60% of cases. In this case the gene is inherited from the mother or father to the child.
Both parents are not necessarily affected and can only be carriers of the gene. In this form, however, retinoblastoma usually develops on both sides. In addition, the risk of further malignant tumors, for example of the bones (osteosarcomas) and connective tissue (soft tissue sarcomas), is increased.
In well developed countries and early diagnosis, the chances of cure are very good. The therapy includes different approaches from chemo-, laser- or surgical therapy, depending on the stage of the tumor, and is performed in specialized centers. If the retinoblastoma is diagnosed early, a treatment concept can be developed and initiated within a short time.
The mortality rate is then only below 5%. Mortality is much higher for untreated or undetected retinoblastomas, as the tumor can spread to different parts of the body over time. Patients with a hereditary retinoblastoma have a worse prognosis because they have a higher risk of further malignant tumors.
Thanks to the latest treatment options, the mortality rate for retinoblastoma, even if it occurs in both eyes, is only about 7%. However, if the optic nerve is also affected, this number increases. Even in cured patients, further tumors occur in 20% of cases, whether in the other eye or in other parts of the body, such as the bone.
Therefore, these patients should be well monitored in order to detect later secondary diseases at an early stage. In addition, the patients should be exposed to as little x-rays as possible and thus to radiation.
