RB1 is a tumor-suppressor gene and individuals who inherit a pathogenic variant (disease-causing) in RB1 are at risk for hereditary retinoblastoma. This is a syndrome characterized by early-onset retinal tumors that may be unilateral (one eye) or bilateral (both eyes), as well as an increased lifetime risk for additional cancers such as osteosarcoma (bone cancer), soft-tissue sarcomas, and certain melanomas. Management focuses on early detection and treatment of retinoblastoma through frequent ophthalmologic exams in infancy and childhood, MRI-based surveillance when indicated, and long-term monitoring for second cancers, particularly in individuals treated with radiation at a young age. Hereditary retinoblastoma is not known to be more common in the Ashkenazi Jewish population.
RB1 exhibits autosomal dominant inheritance. This means there is a 50% chance the condition can be passed from generation-to-generation. First degree relatives (parents, siblings, children) have a 50% chance to have the same pathogenic variant whereas second degree relatives (grandparents, aunts/uncles, nieces/nephews, half-siblings) have a 25% chance. More distant relatives have lower chances of having the same pathogenic variant when one is identified in the family.
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Written December 2025
