Retinoblastoma is a childhood disease. In general, most new cases of retinoblastoma are diagnosed before the age of 5. The overall average age at diagnosis is 18 months. There is no known sex or racial predilection. Approximately 60 percent of cases are only in one eye when first diagnosed, unfortunately about 40 percent of cases present in both eyes.
Retinoblastoma can be either hereditary or non-hereditary.
It is hereditary in 30 to 40 percent of patients. Thus, all children in a family may be at risk. Overall, only six percent of newly diagnosed retinoblastoma patients have a positive family history for the disease. The remaining 75 percent of hereditary cases are caused by new mutations or by inheritance from a parent who carries the gene, but does not have any symptoms. Retinoblastoma does not develop in approximately ten percent of patients who carry the heritable mutation.