What is Hereditary Retinoblastoma?

Retinoblastoma is an eye cancer that typically develops in children before 5 years old. This cancer develops in the retina—the part of the eye that helps a person see color and light. Retinoblastoma is rare, with about 250–300 children diagnosed in the U.S. each year. The disease may be found during routine eye exams of young babies and toddlers.

Parents may notice one or more of the following:

  • A white color to the pupil (the central portion of the eye that is usually black), especially with flash photography
  • A misaligned or “lazy eye” (that may turn outward or inward when the child is looking straight ahead)
  • Vision problems
  • Red or irritated eyes

If retinoblastoma is suspected, the child should be referred to an eye specialist (ophthalmologist). Most patients with retinoblastoma can be cured, especially if the disease is confined to the eyes. If left untreated, it can spread to other parts of the body, where it becomes much harder to treat.

There are two types of retinoblastoma:

  • Sporadic (not passed down in families)
  • Hereditary (can be passed down in families)

Sixty percent of children have only one eye affected. Most of these children have the sporadic form of retinoblastoma. However, about 10–15% may have Hereditary Retinoblastoma. Forty percent of patients have both eyes affected. These children always have the hereditary form. It is important to know whether a person has the hereditary or the sporadic form of retinoblastoma.

The hereditary form carries specific health risks that are not found with the sporadic form. Children with Hereditary Retinoblastoma are at an increased risk to:

  • Develop other tumors (such as more retinoblastoma tumors; pineal gland tumors; skin, bone, and muscle tumors)
  • Develop second cancers after exposure to radiation
  • Transmit the condition to some of their future children

Children with sporadic retinoblastoma are not at risk to transmit the disease to their children, and their risk for developing second cancers is much less than the risk for children with Hereditary Retinoblastoma.

Hereditary Retinoblastoma is caused by changes in a gene known as RB1. Genes carry important information that tells the body’s cells how to work. The RB1 gene controls how cells grow and divide. One of its main jobs is to prevent tumors from forming, particularly retinoblastoma. Normally, cells carry two working copies of RB1. One is inherited from each parent.

Cells from people with Hereditary Retinoblastoma carry one working copy of RB1 and one copy that is changed. This change causes the gene to not work right and is called a variant. When the remaining working copy of RB1 becomes damaged in a cell of the developing retina, it is believed that this can lead to a retinoblastoma tumor. In about 10–20% of Hereditary Retinoblastoma cases, this variant is passed down from a parent who also has Hereditary Retinoblastoma. In the other cases, the affected child has a new variant that was not present in either parent. While this child is the first one in the family to have hereditary retinoblastoma, he or she now has a 50% (1 in 2) chance to pass on the disease to his or her future offspring.

A doctor may suspect this diagnosis after looking at a person’s medical or family history. In most cases, a doctor or genetic counselor will ask questions about the person’s health and the health of other family members. Read more about genetic counseling and genetic testing.

Diagnosing this syndrome is usually done by sequencing the RB1 gene to find variants (changes in genes). This sequencing may be performed with tumor tissue, if available, or from a sample of saliva or blood.

Hereditary Retinoblastoma might start in just one eye. But the chances of it developing in the second eye are high because cells in the other retina contain the altered RB1 gene, too. Other aspects of cancer risk include:

  • Most children with hereditary retinoblastoma develop tumors affecting one or both of the eyes
  • The risk to develop retinoblastoma tumors is greatest during the first 5 years of life
  • A small number of children with Hereditary Retinoblastoma develop cancers outside the eyes, such as in the pineal gland of the brain. Later in life, tumors might form in other parts of the body (bones, muscle, and skin).

Cancer screening involves tests to check for cancer before symptoms occur. The goal is to find cancer at the earliest and most treatable stage. Guidelines for cancer screening are available online. Recommended screenings may change over time as doctors learn more about this syndrome, so these screening tests should be discussed with a health care provider who knows this syndrome well.

Other ideas to reduce the risk of cancer include:

  • Eat a healthful diet with lots of fruits and vegetables
  • Get regular exercise
  • Avoid smoking or using tobacco products
  • Avoid secondhand smoke
  • Avoid excess sun exposure and always wear sunscreen, hat, and protective clothing when out in the sun
  • Get medical attention for unusual or ongoing symptoms

Because of the other medical concerns related to this syndrome, specialists from the following area may need to assess a child with Hereditary Retinoblastoma:

  • Ophthalmology

Resources about Hereditary Retinoblastoma:

Other resources:

Adapted from educational materials developed by the St. Jude Children’s Research Hospital Cancer Predisposition Program