Title :

Targeted sequencing and in vitro splice assays shed light on ABCA4-associated retinopathies missing heritability.

Author(s) :

Corradi, Zelia [Auteur]
Radboud University Medical Center [Nijmegen]
Khan, M. [Auteur]
Hitti-Malin, R. [Auteur]
Mishra, K. [Auteur]
Whelan, L. [Auteur]
Cornelis, S. S. [Auteur]
Hoyng, C. B. [Auteur]
Kämpjärvi, K. [Auteur]
Klaver, C. C. W. [Auteur]
Liskova, P. [Auteur]
Stohr, H. [Auteur]
Weber, B. H. F. [Auteur]
Banfi, S. [Auteur]
Farrar, G. J. [Auteur]
Sharon, D. [Auteur]
Zernant, J. [Auteur]
Allikmets, R. [Auteur]
Dhaenens, Claire-Marie [Auteur]
Lille Neurosciences & Cognition (LilNCog) - U 1172
Cremers, F. P. M. [Auteur]

Journal title :

HGG Adv

Abbreviated title :

HGG Adv

Volume number :

4

Pages :

100237

Publication date :

2023-09-15

ISSN :

2666-2477

HAL domain(s) :

Sciences du Vivant [q-bio]

English abstract : [en]

The ABCA4 gene is the most frequently mutated Mendelian retinopathy-associated gene. Biallelic variants lead to a variety of phenotypes, however, for thousands of cases the underlying variants remain unknown. Here, we aim ...
Show more >The ABCA4 gene is the most frequently mutated Mendelian retinopathy-associated gene. Biallelic variants lead to a variety of phenotypes, however, for thousands of cases the underlying variants remain unknown. Here, we aim to shed further light on the missing heritability of ABCA4-associated retinopathy by analyzing a large cohort of macular dystrophy probands. A total of 858 probands were collected from 26 centers, of whom 722 carried no or one pathogenic ABCA4 variant, while 136 cases carried two ABCA4 alleles, one of which was a frequent mild variant, suggesting that deep-intronic variants (DIVs) or other cis-modifiers might have been missed. After single molecule molecular inversion probes (smMIPs)-based sequencing of the complete 128-kb ABCA4 locus, the effect of putative splice variants was assessed in vitro by midigene splice assays in HEK293T cells. The breakpoints of copy number variants (CNVs) were determined by junction PCR and Sanger sequencing. ABCA4 sequence analysis solved 207 of 520 (39.8%) naive or unsolved cases and 70 of 202 (34.7%) monoallelic cases, while additional causal variants were identified in 54 of 136 (39.7%) probands carrying two variants. Seven novel DIVs and six novel non-canonical splice site variants were detected in a total of 35 alleles and characterized, including the c.6283-321C>G variant leading to a complex splicing defect. Additionally, four novel CNVs were identified and characterized in five alleles. These results confirm that smMIPs-based sequencing of the complete ABCA4 gene provides a cost-effective method to genetically solve retinopathy cases and that several rare structural and splice altering defects remain undiscovered in Stargardt disease cases.Show less >

Language :

Anglais

Audience :

Internationale

Popular science :

Non

Administrative institution(s) :

Université de Lille
Inserm
CHU Lille

Collections :

• Lille Neurosciences & Cognition (LilNCog) - U 1172

Submission date :

2024-01-15T22:27:26Z
2024-09-18T09:41:47Z