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Esteve-Garcia A, Cobos E, Sau C, Padró-Miquel A, Català-Mora J, Barberán-Martínez P, Millán JM, García-García G, Aguilera C. Deciphering complexity: TULP1 variants linked to an atypical retinal dystrophy phenotype. Front Genet 2024; 15:1352063. [PMID: 38450199 PMCID: PMC10915255 DOI: 10.3389/fgene.2024.1352063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Accepted: 01/29/2024] [Indexed: 03/08/2024] Open
Abstract
Introduction: TULP1 exemplifies the remarkable clinical and genetic heterogeneity observed in inherited retinal dystrophies. Our research describes the clinical and molecular characteristics of a patient manifesting an atypical retinal dystrophy pattern, marked by the identification of both a previously unreported and a rarely encountered TULP1 variant. Methods: Whole-exome sequencing was performed to identify potential causative variants. The pathogenicity of the identified TULP1 variants was evaluated through in silico predictors and a minigene splice assay, specifically designed to assess the effect of the unreported TULP1 variant. Results: We identified two TULP1 gene variants in a patient exhibiting unusual and symmetrical alterations in both retinas, characterized by an increase in autofluorescence along the distribution of retinal vessels. These variants included a known rare missense variant, c.1376T>C, and a novel splice site variant, c.822G>T. For the latter variant (c.822G>T), we conducted a minigene splice assay that demonstrated the incorporation of a premature stop codon. This finding suggests a likely activation of the nonsense-mediated mRNA decay mechanism, ultimately resulting in the absence of protein production from this allele. Segregation analysis confirmed that these variants were in trans. Discussion: Our data support that individuals with biallelic TULP1 variants may present with a unique pattern of macular degeneration and periarteriolar vascular pigmentation. This study highlights the importance of further clinical and molecular characterization of TULP1 variants to elucidate genotype-phenotype correlations in the context of inherited retinal dystrophies.
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Affiliation(s)
- Anna Esteve-Garcia
- Department of Clinical Genetics, Bellvitge University Hospital, Institut d’Investigació Biomèdica de Bellvitge (IDIBELL), L'Hospitalet de Llobregat, Barcelona, Spain
| | - Estefania Cobos
- Department of Ophthalmology, Bellvitge University Hospital, Institut d’Investigació Biomèdica de Bellvitge (IDIBELL), L'Hospitalet de Llobregat, Barcelona, Spain
| | - Cristina Sau
- Department of Clinical Genetics, Bellvitge University Hospital, Institut d’Investigació Biomèdica de Bellvitge (IDIBELL), L'Hospitalet de Llobregat, Barcelona, Spain
| | - Ariadna Padró-Miquel
- Genetics Laboratory, Bellvitge University Hospital, Institut d’Investigació Biomèdica de Bellvitge (IDIBELL), L'Hospitalet de Llobregat, Barcelona, Spain
| | - Jaume Català-Mora
- Department of Ophthalmology, SJD Barcelona Children’s Hospital, Barcelona, Spain
| | - Pilar Barberán-Martínez
- Molecular, Cellular, and Genomic Biomedicine Group, Valencia, Spain
- Joint Unit CIPF-IIS La Fe Molecular, Cellular and Genomic Biomedicine, Valencia, Spain
| | - José M. Millán
- Molecular, Cellular, and Genomic Biomedicine Group, Valencia, Spain
- Joint Unit CIPF-IIS La Fe Molecular, Cellular and Genomic Biomedicine, Valencia, Spain
- Center for Rare Diseases (CIBERER), Madrid, Spain
- University and Polytechnic La Fe Hospital of Valencia, Valencia, Spain
| | - Gema García-García
- Molecular, Cellular, and Genomic Biomedicine Group, Valencia, Spain
- Joint Unit CIPF-IIS La Fe Molecular, Cellular and Genomic Biomedicine, Valencia, Spain
- Center for Rare Diseases (CIBERER), Madrid, Spain
| | - Cinthia Aguilera
- Genetics Laboratory, Bellvitge University Hospital, Institut d’Investigació Biomèdica de Bellvitge (IDIBELL), L'Hospitalet de Llobregat, Barcelona, Spain
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