Comprehensive analysis of clinical phenotype and genetic characteristics of retinoblastoma caused by RB1 gene mutation: a case series

This study aimed to summarize the clinical and genetic characteristics of retinoblastoma associated with newly identified RB1 gene mutations. We retrospectively analyzed 15 pediatric patients diagnosed with retinoblastoma caused by RB1 mutations. A total of 25 affected eyes were examined (8 males, 7 females). The age at diagnosis ranged from 7 to 36 months (mean 16.00 ± 8.61 months). Bilateral involvement was observed in 10 patients, and unilateral in 5. Thirteen patients presented with leukocoria, while 2 were diagnosed during routine physical examinations due to vision loss. None of the patients had a family history of retinoblastoma. Whole-exome sequencing revealed heterozygous RB1 mutations in 14 cases and a mosaic mutation in one case. Five novel mutations not previously reported in the literature were identified: c.608-1G>A, c.1818T>A, c.962dupA, c.2086A>T, and c.574A>T. All patients received treatment, including intra-arterial chemotherapy, cryotherapy, photocoagulation, systemic chemotherapy, and/or enucleation. The follow-up duration ranged from 12 to 132 months, with a mean of 39.20 ± 24.07 months. Genetic testing remains a valuable tool for confirming RB1 mutations. Expanding the RB1 mutation spectrum may facilitate early diagnosis, personalized treatment, and informed genetic counseling for affected children.