Retinoblastoma is a malignant tumor of the retina that occurs primarily in young children as
a result of mutations in the retinoblastoma gene (RB), the first tumor suppressor gene to be
identified. In about 35% to 40% of patients with retinoblastoma, anRBgene mutation is
present in the germline, resulting in hereditary transmission of the disease. Most families
with hereditary retinoblastoma demonstrate autosomal dominant inheritance with almost
complete penetrance and high expressivity. However, some families display an inheritance …