Definition for retinoblastoma

Retinoblastoma is a cancer of the retina. Development of this tumor is initiated by mutations that inactivate both copies of the RB1-gene, which codes for the Rb-1 protein. more

Retinoblastoma is a cancer of the retina. Development of this tumor is initiated by mutations that inactivate both copies of the RB1-gene, which codes for the Rb-1 protein. It occurs mostly in children younger than 5 years and accounts for about 3% of the cancers occurring in children younger than 15 years. Adult cases have also been clinically recorded. The estimated annual incidence is approximately 4 per million children. It begins with white blotches in one or both eyes which are apparent only in photographs (this is distinct from the red-eye effect which is normal). less