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 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.
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.
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.