Mutation spectrum of retinoblastoma patients in Vietnam

Abstract

Background: Retinoblastoma (RB), an intraocular malignancy commonly diagnosed in children, is mostly caused by inactivating mutations of both alleles of the RB1 gene. Early genetic screening for RB1 gene mutations would greatly improve treatment outcomes and patient management. Methods: In this study, both somatic and germline mutations were detected in blood and tumour samples of 42 RB patients using direct sequencing and multiplex ligation-dependent probe amplification. Results: In total, 34 different mutations were found in 36 patients, including 1 SNP, 4 large deletions, 5 splicing sites, 1 missense, 7 frameshifts and 17 nonsense mutations. There were five novel mutations and one unreported which have not been found in large databases such as Leiden Open Variation Database (LOVD) and ClinVar. Conclusion: A higher rate of RB patients carrying heterozygous germline mutation and highly prevalent with pathogenic truncated mutation, hence, early detection of RB is essential for vision salvation and genetic counselling.