Heritable Retinoblastoma

Heritable retinoblastoma follows a dominant inheritance pattern. This means that having one faulty copy of the RB1 gene can result in an increased risk of cancer. It can affect both males and females.

Everyone has 2 copies of each gene in their body’s cells:

• 1 copy comes from our father
• 1 copy comes from our mother

A parent with a faulty RB1 gene has a 50% chance of passing down their faulty gene to their children. A child carrying the faulty RB1 gene also has a 50% chance of passing down the faulty gene to each of their future children. Relatives of the carriers of the faulty RB1 gene may have also inherited the same faulty gene.

Not all children with heritable retinoblastoma inherited the faulty RB1 gene from one of their parents.

Often, both parents are not carriers but the child has acquired a faulty RB1 gene (de novo) at conception. As this child carries the faulty gene, they can pass it on to their future children, but their other family members would not be at risk.

While most people who have a faulty RB1 gene develop retinoblastoma, some individuals who carry the faulty gene may not develop etinoblastoma or other cancers. Therefore, the disease may present differently among family members.