Case Report: A novel germline donor splicing site mutation of RB1 gene in a Chinese Tibetan pedigree with familial retinoblastoma

Retinoblastoma (RB) is the most common primary intraocular malignancy in children and mostly initiates with biallelic inactivation of the RB1 gene. Hereditary retinoblastoma accounts for 40% of all cases, with only 6%–10% of patients having a positive family history. The proband, a Chinese Tibetan b...

Full description

Saved in:
Bibliographic Details
Main Authors: Guo-qian He, Ying-chun Zheng, Lin-jun Tan, Cheng-qi Shen, Ju Gao, Fu Xiong, Xia Guo
Format: Article
Language:English
Published: Frontiers Media S.A. 2025-05-01
Series:Frontiers in Oncology
Subjects:
Online Access:https://www.frontiersin.org/articles/10.3389/fonc.2025.1525035/full
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1849735730707824640
author Guo-qian He
Guo-qian He
Ying-chun Zheng
Lin-jun Tan
Lin-jun Tan
Cheng-qi Shen
Cheng-qi Shen
Ju Gao
Ju Gao
Fu Xiong
Xia Guo
Xia Guo
author_facet Guo-qian He
Guo-qian He
Ying-chun Zheng
Lin-jun Tan
Lin-jun Tan
Cheng-qi Shen
Cheng-qi Shen
Ju Gao
Ju Gao
Fu Xiong
Xia Guo
Xia Guo
author_sort Guo-qian He
collection DOAJ
description Retinoblastoma (RB) is the most common primary intraocular malignancy in children and mostly initiates with biallelic inactivation of the RB1 gene. Hereditary retinoblastoma accounts for 40% of all cases, with only 6%–10% of patients having a positive family history. The proband, a Chinese Tibetan boy, was diagnosed with RB for leukocoria. The RB1 gene mutations were screened due to disease recurrence. A novel germline donor splicing site mutation (c.861 + 2T>A) from his father was identified by Sanger sequencing and a novel somatic duplication mutation in exon 2 221-224 (p.W75Cfs*36) by next-generation sequencing (NGS). The proband’s younger brother manifested bilateral RB and also carried the same germline mutation. To further explore the possible pathogenicity of the novel germline RB1 mutation (c.861 + 2T>A) in RB development, mutation analysis, bioinformatics analysis, and immunohistochemistry were performed. After RB1 cDNA was amplified, the abnormal script was found to be smaller than the normal script. Compared with normal samples, Sanger sequencing revealed a deletion of 143 bp in the abnormal script. In comparison to healthy individuals, patients exhibited a reduction in the mRNA expression levels of the RB1 gene. The three-dimensional structure predicted by iterative threading assembly refinement (I-TASSER) indicates significant changes in the spatial structure of abnormal proteins after mutation. No expression of RB1 was found in tumor tissue by immunohistochemistry evaluation. Therefore, the novel germline donor splicing site mutation (c.861 + 2T>A) has been confirmed to be a pathological mutation.
format Article
id doaj-art-2813eb1632b24ce79ea625e84ef0e3c5
institution DOAJ
issn 2234-943X
language English
publishDate 2025-05-01
publisher Frontiers Media S.A.
record_format Article
series Frontiers in Oncology
spelling doaj-art-2813eb1632b24ce79ea625e84ef0e3c52025-08-20T03:07:28ZengFrontiers Media S.A.Frontiers in Oncology2234-943X2025-05-011510.3389/fonc.2025.15250351525035Case Report: A novel germline donor splicing site mutation of RB1 gene in a Chinese Tibetan pedigree with familial retinoblastomaGuo-qian He0Guo-qian He1Ying-chun Zheng2Lin-jun Tan3Lin-jun Tan4Cheng-qi Shen5Cheng-qi Shen6Ju Gao7Ju Gao8Fu Xiong9Xia Guo10Xia Guo11Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, Sichuan, ChinaKey Laboratory of Birth Defects and Related Diseases of Women and Children (Sichuan University), Ministry of Education, Chengdu, Sichuan, ChinaDepartment of Medical Genetics, School of Basic Medical Sciences, Southern Medical University, Guangzhou, ChinaKey Laboratory of Birth Defects and Related Diseases of Women and Children (Sichuan University), Ministry of Education, Chengdu, Sichuan, ChinaDepartment of Pediatrics, Affiliated Hospital of Zunyi Medical University, Zunyi, ChinaDepartment of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, Sichuan, ChinaKey Laboratory of Birth Defects and Related Diseases of Women and Children (Sichuan University), Ministry of Education, Chengdu, Sichuan, ChinaKey Laboratory of Birth Defects and Related Diseases of Women and Children (Sichuan University), Ministry of Education, Chengdu, Sichuan, ChinaNHC Key Laboratory of Chronobiology, Sichuan University, Chengdu, ChinaDepartment of Medical Genetics, School of Basic Medical Sciences, Southern Medical University, Guangzhou, ChinaDepartment of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, Sichuan, ChinaNHC Key Laboratory of Chronobiology, Sichuan University, Chengdu, ChinaRetinoblastoma (RB) is the most common primary intraocular malignancy in children and mostly initiates with biallelic inactivation of the RB1 gene. Hereditary retinoblastoma accounts for 40% of all cases, with only 6%–10% of patients having a positive family history. The proband, a Chinese Tibetan boy, was diagnosed with RB for leukocoria. The RB1 gene mutations were screened due to disease recurrence. A novel germline donor splicing site mutation (c.861 + 2T>A) from his father was identified by Sanger sequencing and a novel somatic duplication mutation in exon 2 221-224 (p.W75Cfs*36) by next-generation sequencing (NGS). The proband’s younger brother manifested bilateral RB and also carried the same germline mutation. To further explore the possible pathogenicity of the novel germline RB1 mutation (c.861 + 2T>A) in RB development, mutation analysis, bioinformatics analysis, and immunohistochemistry were performed. After RB1 cDNA was amplified, the abnormal script was found to be smaller than the normal script. Compared with normal samples, Sanger sequencing revealed a deletion of 143 bp in the abnormal script. In comparison to healthy individuals, patients exhibited a reduction in the mRNA expression levels of the RB1 gene. The three-dimensional structure predicted by iterative threading assembly refinement (I-TASSER) indicates significant changes in the spatial structure of abnormal proteins after mutation. No expression of RB1 was found in tumor tissue by immunohistochemistry evaluation. Therefore, the novel germline donor splicing site mutation (c.861 + 2T>A) has been confirmed to be a pathological mutation.https://www.frontiersin.org/articles/10.3389/fonc.2025.1525035/fullretinoblastomaRB1 genedonor splicing site mutationgermlinechild
spellingShingle Guo-qian He
Guo-qian He
Ying-chun Zheng
Lin-jun Tan
Lin-jun Tan
Cheng-qi Shen
Cheng-qi Shen
Ju Gao
Ju Gao
Fu Xiong
Xia Guo
Xia Guo
Case Report: A novel germline donor splicing site mutation of RB1 gene in a Chinese Tibetan pedigree with familial retinoblastoma
Frontiers in Oncology
retinoblastoma
RB1 gene
donor splicing site mutation
germline
child
title Case Report: A novel germline donor splicing site mutation of RB1 gene in a Chinese Tibetan pedigree with familial retinoblastoma
title_full Case Report: A novel germline donor splicing site mutation of RB1 gene in a Chinese Tibetan pedigree with familial retinoblastoma
title_fullStr Case Report: A novel germline donor splicing site mutation of RB1 gene in a Chinese Tibetan pedigree with familial retinoblastoma
title_full_unstemmed Case Report: A novel germline donor splicing site mutation of RB1 gene in a Chinese Tibetan pedigree with familial retinoblastoma
title_short Case Report: A novel germline donor splicing site mutation of RB1 gene in a Chinese Tibetan pedigree with familial retinoblastoma
title_sort case report a novel germline donor splicing site mutation of rb1 gene in a chinese tibetan pedigree with familial retinoblastoma
topic retinoblastoma
RB1 gene
donor splicing site mutation
germline
child
url https://www.frontiersin.org/articles/10.3389/fonc.2025.1525035/full
work_keys_str_mv AT guoqianhe casereportanovelgermlinedonorsplicingsitemutationofrb1geneinachinesetibetanpedigreewithfamilialretinoblastoma
AT guoqianhe casereportanovelgermlinedonorsplicingsitemutationofrb1geneinachinesetibetanpedigreewithfamilialretinoblastoma
AT yingchunzheng casereportanovelgermlinedonorsplicingsitemutationofrb1geneinachinesetibetanpedigreewithfamilialretinoblastoma
AT linjuntan casereportanovelgermlinedonorsplicingsitemutationofrb1geneinachinesetibetanpedigreewithfamilialretinoblastoma
AT linjuntan casereportanovelgermlinedonorsplicingsitemutationofrb1geneinachinesetibetanpedigreewithfamilialretinoblastoma
AT chengqishen casereportanovelgermlinedonorsplicingsitemutationofrb1geneinachinesetibetanpedigreewithfamilialretinoblastoma
AT chengqishen casereportanovelgermlinedonorsplicingsitemutationofrb1geneinachinesetibetanpedigreewithfamilialretinoblastoma
AT jugao casereportanovelgermlinedonorsplicingsitemutationofrb1geneinachinesetibetanpedigreewithfamilialretinoblastoma
AT jugao casereportanovelgermlinedonorsplicingsitemutationofrb1geneinachinesetibetanpedigreewithfamilialretinoblastoma
AT fuxiong casereportanovelgermlinedonorsplicingsitemutationofrb1geneinachinesetibetanpedigreewithfamilialretinoblastoma
AT xiaguo casereportanovelgermlinedonorsplicingsitemutationofrb1geneinachinesetibetanpedigreewithfamilialretinoblastoma
AT xiaguo casereportanovelgermlinedonorsplicingsitemutationofrb1geneinachinesetibetanpedigreewithfamilialretinoblastoma