2026-04-17T00:54:53Zhttps://recercat.cat/oai/request

oai:recercat.cat:11351/128102025-10-24T10:18:05Zcom_2072_378070com_2072_378040col_2072_378092

00925njm 22002777a 4500 dc GOMEZ MARIANO, GEMA author Hernandez-SanMiguel, Esther author Fernández-Prieto, Marta author Ramos-Del Saz, Sheila author Baladrón, Beatriz author Mielu, Lidia Mirela author Sabado, Constantino author 2025-03-21T09:21:38Z 2025-03-21T09:21:38Z 2025-02 Mosaicism; Next generation sequencing; Retinoblastoma Mosaicismo; Secuenciación de nueva generación; Retinoblastoma Mosaicisme; Seqüenciació de nova generació; Retinoblastoma Constitutional variants in the RB1 gene predispose individuals to the development of Retinoblastoma (RB) and the occurrence of second tumors in adulthood. Detection of causal RB1 gene variants is essential to establish the genetic diagnosis and to performing familial studies and counseling. In our cohort of 579 Spanish RB patients, 15% of cases suspected to have a genetic origin remained negative after traditional Sanger sequencing and Multiplex Ligation-dependent Probe Amplification (MLPA) of RB1 gene, likely due to the possibility of mosaicism or non-coding variants. A specific next-generation sequencing (NGS) gene panel was designed to analyze the complete sequence of the RB1 gene. While many familial RB cases showed variants through Sanger and MLPA, the analysis of 65 available sporadic RB patients using the NGS gene panel identified a causative variant in an additional 6 of 26 (23%) bilateral cases and 6 of 39 (15.4%) unilateral cases. Seven of these cases exhibited different degrees of mosaicism (26%, 20%, 15.8%, 8%, 6%, 5.9% and 3%) while 5 cases had heterozygous deep intronic variants, all of them previously described in RB patients. Additional cases with suspected variants, not detected in blood but present in tumor tissue, were also analyzed using NGS PCR amplicons, and mosaicism was confirmed in other 10 sporadic cases. Altogether, the use of NGS increased the diagnostic yield, particularly for patients with sporadic RB in 10 bilateral cases and in 12 unilateral cases. The Instituto de Salud Carlos III of Madrid has supported this work (PT23CIII/00003). We acknowledge the genomics and bioinformatics services of the Instituto de Salud Carlos III for their participation in this study. We would like to thank Belén Marugán Gómez for the illustration of the figure presented in Highlights. http://hdl.handle.net/11351/12810 Anomalies cromosòmiques Retina - Càncer - Diagnòstic Retina - Càncer - Aspectes genètics Mosaïcisme PHENOMENA AND PROCESSES::Genetic Phenomena::Genetic Variation::Mutation::Chromosome Aberrations::Mosaicism DISEASES::Neoplasms::Neoplasms::Neoplasms::Neoplasms::Neoplasms by Site::Eye Neoplasms::Retinal Neoplasms::Retinoblastoma Other subheadings::Other subheadings::/diagnosis PHENOMENA AND PROCESSES::Genetic Phenomena::Genetic Variation::Mutation FENÓMENOS Y PROCESOS::fenómenos genéticos::variación genética::mutación::aberraciones cromosómicas::mosaicismo ENFERMEDADES::neoplasias::neoplasias::neoplasias::neoplasias::neoplasias por localización::neoplasias del ojo::neoplasias de la retina::retinoblastoma Otros calificadores::Otros calificadores::/diagnóstico FENÓMENOS Y PROCESOS::fenómenos genéticos::variación genética::mutación Mosaicism and intronic variants in RB1 gene revealed by next generation sequencing in a cohort of Spanish retinoblastoma patients