Germline methylation of the RB1 gene promoter was studied in a particular pedigree of six generations from the paternal side, with incomplete penetrance and bias towards healthy male carriers and those affected with unilateral retinoblastoma.
Our patient had a novel translocation affecting the retinoblastoma 1 (RB1) gene, 46,XX,t(11;13)(q21;q14.2) resulting in the late development of unilateral retinoblastoma.
Our data show that early age at diagnosis does not identify patients with isolated unilateral retinoblastoma that have a higher risk of being carriers of a RB1 gene mutation.
To determine the frequency and nature of constitutional RB1-gene mutations in patients with isolated unilateral retinoblastoma, we analyzed DNA from peripheral blood and from tumor tissue.