Retinoblastoma is a rare type of eye cancer that usually develops in early childhood, typically before the age of 5. This form of cancer develops in the retina, which is the specialized light-sensitive tissue at the back of the eye that detects light and color.

Mutations in the RB1 gene are responsible for most cases of retinoblastoma. RB1 is a tumor suppressor gene, which means that it normally regulates cell growth and stops cells from dividing too rapidly or in an uncontrolled way. Most mutations in the RB1 gene prevent it from making any functional protein, so cells are unable to regulate cell division effectively. As a result, certain cells in the retina can divide uncontrollably to form a cancerous tumor. Some studies suggest that additional genetic changes can influence the development of retinoblastoma; these changes may help explain variations in the development and growth of retinoblastoma and other types of tumors in different people.

Retinoblastoma is diagnosed in 250 to 350 children per year in the United States. It accounts for about 4 percent of all cancers in children younger than 15 years.

Researchers estimate that one-third of all retinoblastomas are hereditary, which means that RB1 gene mutations are present in all of the body's cells, including reproductive cells (sperm or eggs). People with hereditary retinoblastoma may have a family history of the disease, and they are at risk of passing on the mutated RB1 gene to the next generation. The other two-thirds of retinoblastomas are non-hereditary, which means that RB1 gene mutations are present only in cells of the eye and cannot be passed to the next generation.

Published Date: December 01, 2017
Published By: National Institutes of Health