Combining targeted panel-based resequencing and copy-number variation analysis for the diagnosis of inherited syndromic retinopathies and associated ciliopathies

• Published in: Scientific reports 2018-03, Vol.8 (1), p.5285-11, Article 5285
• Main Authors: Sanchez-Navarro, Iker, R. J. da Silva, Luciana, Blanco-Kelly, Fiona, Zurita, Olga, Sanchez-Bolivar, Noelia, Villaverde, Cristina, Lopez-Molina, Maria Isabel, Garcia-Sandoval, Blanca, Tahsin-Swafiri, Saoud, Minguez, Pablo, Riveiro-Alvarez, Rosa, Lorda, Isabel, Sanchez-Alcudia, Rocío, Perez-Carro, Raquel, Valverde, Diana, Liu, Yichuan, Tian, Lifeng, Hakonarson, Hakon, Avila-Fernandez, Almudena, Corton, Marta, Ayuso, Carmen
• Format: Article
• Language: English
• Subjects: 45/23; 45/61; 692/308/2056; 692/699/3161/3175; Diagnosis; Disease; Genes; Genetics; Genomics; Heterogeneity; Hospitals; Humanities and Social Sciences; MKKS protein; multidisciplinary; Mutation; Otx2 protein; Retina; Science; Science (multidisciplinary); USH2A protein
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-018-23520-1

Inherited syndromic retinopathies are a highly heterogeneous group of diseases that involve retinal anomalies and systemic manifestations. They include retinal ciliopathies, other well-defined clinical syndromes presenting with retinal alterations and cases of non-specific multisystemic diseases. The heterogeneity of these conditions makes molecular and clinical characterization of patients challenging in daily clinical practice. We explored the capacity of targeted resequencing and copy-number variation analysis to improve diagnosis of a heterogeneous cohort of 47 patients mainly comprising atypical cases that did not clearly fit a specific clinical diagnosis. Thirty-three likely pathogenic variants were identified in 18 genes ( ABCC6, ALMS1, BBS1, BBS2, BBS12, CEP41, CEP290, IFT172, IFT27, MKKS, MYO7A, OTX2, PDZD7, PEX1, RPGRIP1, USH2A, VPS13B, and WDPCP ). Molecular findings and additional clinical reassessments made it possible to accurately characterize 14 probands (30% of the total). Notably, clinical refinement of complex phenotypes was achieved in 4 cases, including 2 de novo OTX2 -related syndromes, a novel phenotypic association for the ciliary CEP41 gene, and the co-existence of biallelic USH2A variants and a Koolen-de-Vries syndrome–related 17q21.31 microdeletion. We demonstrate that combining next-generation sequencing and CNV analysis is a comprehensive and useful approach to unravel the extensive phenotypic and genotypic complexity of inherited syndromic retinopathies.