Genetic Counseling and Testing for Retinoblastoma
If you have a child with retinoblastoma, your doctor may suggest your family consider genetic counseling. This is because some retinoblastomas are caused by a genetic mutation that can be inherited.
If a child is diagnosed with retinoblastoma in both eyes, it can be assumed that they have the hereditary form of the disease (even if there is no family history of the disease), which means they carry the mutant RB1 gene in all their cells. Some children with retinoblastoma in only one eye might also carry the mutant RB1 gene in all their cells. This can be confirmed with a blood test. Children with this mutant gene are at increased risk for developing other cancers later in life (see the section Second Cancers After Retinoblastoma), and will have a 1 in 2 chance of passing the RB1 gene change on to each of their children.
If the child carries the mutated RB1 gene, then other children in the family might have inherited the same abnormal gene as well. Meeting with a genetic counselor can give you a better idea of what this risk might be and if other children in the family should be tested for the mutation. The genetic counselor will:
- Review the child’s medical records and ask questions about other relatives to estimate the likelihood of an inherited gene affecting some family members.
- Provide information and answer questions about genetic testing, and schedule tests for other children in your family (if needed) to help determine their risk of developing retinoblastoma.
If tests show your children are at risk of developing retinoblastoma, their doctors will follow them very closely to find retinoblastoma at the earliest possible stage, if it occurs. It’s very helpful to be able to tell which children have inherited the mutation that leads to retinoblastoma, since those children will need to be monitored closely.
Sometimes it’s not possible to tell with certainty if a child inherited the RB1 gene mutation. In those cases the safest plan is to monitor children in the family closely for retinoblastoma with frequent eye exams.
Last Medical Review: March 12, 2015 Last Revised: March 12, 2015