Genetic characteristics of patients with bilateral retinoblastoma treated at the Vietnam National Eye Hospital during 2021-2023

Abstract

Retinoblastoma is a common pediatric cancer. The bilateral form, while less frequent, is more complicated than the unilateral form. This study analysed the genetic characteristics of: (1) 8 patients diagnosed and treated at Vietnam National Eye Hospital from 07/2021 to 08/2023 and (2) their family members. Using genetic sequencing and amplification techniques, RB1 gene mutations were found in both the tumor and blood samples of 7 patients, but only in the tumor sample of 1 patient. Seven exonic mutations were found in 6 out of 8 cases, including 4 nonsense mutations, 2 frameshifts, and 1 large-deletion mutation. Two splice-site mutations, including a novel one, were found in the other 2 cases. Among the 5 families participating in the study, only 1 family was found to have the mutation. All patients have pathogenic RB1 gene mutations, with a significant proportion of mutations inherited from parent(s), so early detection of mutation is crucial for management and genetic counselling.