Herausforderungen und Fallstricken zum Trotz: Wie die Ophthalmologie von Next-Generation Sequencing profitiert

Zusammenfassung

Innerhalb weniger Jahre ist die Anwendung von Hochdurchsatzsequenzierung (next-generation sequencing, NGS) in der genetischen Diagnostik zur Routine geworden und hat die konventionelle Sanger-Sequenzierung aus vielen Bereichen weitgehend verdrängt. Mit der Komplexität der Daten gehen besondere Anforderungen insbesondere an die Bioinformatik einher, da die Identifizierung der krankheitsauslösenden Varianten schwierig sein kann und falsche Schlussfolgerungen vermieden werden sollen. Man kann aber, wenn man exemplarisch für andere (Augen-)Erkrankungen die Retinopathien als Gruppe mit ausgeprägter genetischer Heterogenität betrachtet, schon heute sagen, dass die NGS-basierte Diagnostik den meisten Patienten und den betreuenden Ärzten wichtige Informationen liefert und unser Wissen maßgeblich erweitert hat. In der ophthalmogenetischen Forschung hat NGS zudem zur Identifizierung zahlreicher neuer Krankheitsgene geführt.

Abstract

Within a few years, high-throughput sequencing (next-generation sequencing, NGS) has become a routine method in genetic diagnostics and has largely replaced conventional Sanger sequencing. The complexity of NGS data requires sound bioinformatic analysis: pinpointing the disease-causing variants may be difficult, and erroneous interpretations must be avoided. When looking at the group of retinal dystrophies as an example of eye disorders with extensive genetic heterogeneity, one can clearly say that NGS-based diagnostics yield important information for most patients and physicians, and that it has furthered our knowledge significantly. Furthermore, NGS has accelerated ophthalmogenetic research aimed at the identification of novel eye disease genes.

Schlüsselwörter

Genetik - Next-Generation Sequencing - retinale Dystrophien - allelische Erkrankungen

Key words

genetics - next-generation sequencing - retinal dystrophies - allelic disorders

• Literatur

• 1 Bolz HJ. Next-generation sequencing: a quantum leap in ophthalmology research and diagnostics. Klin Monatsbl Augenheilkd 2017; 234: 280-288
• 2 Eisenberger T, Neuhaus C, Khan AO. et al. Increasing the yield in targeted next-generation sequencing by implicating CNV analysis, non-coding exons and the overall variant load: the example of retinal dystrophies. PLoS One 2013; 8: e78496
• 3 Zhang L, Zheng A, Nie H. et al. Laser-induced photic injury phenocopies macular dystrophy. Ophthalmic Genet 2016; 37: 59-67
• 4 Roosing S, van den Born LI, Sangermano R. et al. Mutations in MFSD8, encoding a lysosomal membrane protein, are associated with nonsyndromic autosomal recessive macular dystrophy. Ophthalmology 2015; 122: 170-179
• 5 Wang X, Wang H, Sun V. et al. Comprehensive molecular diagnosis of 179 Leber congenital amaurosis and juvenile retinitis pigmentosa patients by targeted next generation sequencing. J Med Genet 2013; 50: 674-688
• 6 Wang F, Wang H, Tuan HF. et al. Next generation sequencing-based molecular diagnosis of retinitis pigmentosa: identification of a novel genotype-phenotype correlation and clinical refinements. Hum Genet 2014; 133: 331-345
• 7 Aldahmesh MA, Safieh LA, Alkuraya H. et al. Molecular characterization of retinitis pigmentosa in Saudi Arabia. Mol Vis 2009; 15: 2464-2469
• 8 Riazuddin SA, Iqbal M, Wang Y. et al. A splice-site mutation in a retina-specific exon of BBS8 causes nonsyndromic retinitis pigmentosa. Am J Hum Genet 2010; 86: 805-812
• 9 Estrada-Cuzcano A, Koenekoop RK, Senechal A. et al. BBS1 mutations in a wide spectrum of phenotypes ranging from nonsyndromic retinitis pigmentosa to Bardet-Biedl syndrome. Arch Ophthalmol 2012; 130: 1425-1432
• 10 Bujakowska KM, Zhang Q, Siemiatkowska AM. et al. Mutations in IFT172 cause isolated retinal degeneration and Bardet-Biedl syndrome. Hum Mol Genet 2015; 24: 230-242
• 11 Khan AO, Decker E, Bachmann N. et al. C8orf37 is mutated in Bardet-Biedl syndrome and constitutes a locus allelic to non-syndromic retinal dystrophies. Ophthalmic Genet 2016; 37: 290-293
• 12 Estrada-Cuzcano A, Koenekoop RK, Coppieters F. et al. IQCB1 mutations in patients with Leber congenital amaurosis. Invest Ophthalmol Vis Sci 2011; 52: 834-839
• 13 Bifari IN, Elkhamary SM, Bolz HJ. et al. The ophthalmic phenotype of IFT140-related ciliopathy ranges from isolated to syndromic congenital retinal dystrophy. Br J Ophthalmol 2016; 100: 829-833
• 14 Nguyen TT, Hull S, Roepman R. et al. Missense mutations in the WD40 domain of AHI1 cause non-syndromic retinitis pigmentosa. J Med Genet 2017; 54: 624-632
• 15 Durlu YK, Koroglu C, Tolun A. Novel recessive cone-rod dystrophy caused by POC1B mutation. JAMA Ophthalmol 2014; 132: 1185-1191
• 16 Haer-Wigman L, Newman H, Leibu R. et al. Non-syndromic retinitis pigmentosa due to mutations in the mucopolysaccharidosis type IIIC gene, heparan-alpha-glucosaminide N-acetyltransferase (HGSNAT). Hum Mol Genet 2015; 24: 3742-3751
• 17 Zaki MS, Heller R, Thoenes M. et al. PEX6 is expressed in photoreceptor cilia and mutated in deafblindness with enamel dysplasia and microcephaly. Hum Mutat 2016; 37: 170-174
• 18 Neuhaus C, Eisenberger T, Decker C. et al. Next-generation sequencing reveals the mutational landscape of clinically diagnosed Usher syndrome: copy number variations, phenocopies, a predominant target for translational read-through, and PEX26 mutated in Heimler syndrome. Mol Genet Genomic Med 2017; 5: 531-552
• 19 Ratbi I, Falkenberg KD, Sommen M. et al. Heimler Syndrome is caused by hypomorphic mutations in the peroxisome-biogenesis genes PEX1 and PEX6. Am J Hum Genet 2015; 97: 535-545
• 20 Ruether K, Baldwin E, Casteels M. et al. Adult Refsum disease: a form of tapetoretinal dystrophy accessible to therapy. Surv Ophthalmol 2010; 55: 531-538
• 21 Khan AO, Eisenberger T, Nagel-Wolfrum K. et al. C21orf2 is mutated in recessive early-onset retinal dystrophy with macular staphyloma and encodes a protein that localises to the photoreceptor primary cilium. Br J Ophthalmol 2015; 99: 1725-1731
• 22 Sullivan LS, Bowne SJ, Birch DG. et al. Prevalence of disease-causing mutations in families with autosomal dominant retinitis pigmentosa: a screen of known genes in 200 families. Invest Ophthalmol Vis Sci 2006; 47: 3052-3064
• 23 Sullivan LS, Bowne SJ, Reeves MJ. et al. Prevalence of mutations in eyeGENE probands with a diagnosis of autosomal dominant retinitis pigmentosa. Invest Ophthalmol Vis Sci 2013; 54: 6255-6261
• 24 Khaliq S, Abid A, Ismail M. et al. Novel association of RP1 gene mutations with autosomal recessive retinitis pigmentosa. J Med Genet 2005; 42: 436-438
• 25 Riazuddin SA, Zulfiqar F, Zhang Q. et al. Autosomal recessive retinitis pigmentosa is associated with mutations in RP1 in three consanguineous Pakistani families. Invest Ophthalmol Vis Sci 2005; 46: 2264-2270
• 26 Elsayed SM, Phillips JB, Heller R. et al. Non-manifesting AHI1 truncations indicate localized loss-of-function tolerance in a severe Mendelian disease gene. Hum Mol Genet 2015; 24: 2594-2603
• 27 Bell CJ, Dinwiddie DL, Miller NA. et al. Carrier testing for severe childhood recessive diseases by next-generation sequencing. Sci Transl Med 2011; 3: 65ra4
• 28 Preising MN, Bolz HJ. Segregation analysis in inherited eye disorders: an academic add-on or an essential effort?. Klin Monatsbl Augenheilkd 2017; 234: 272-279
• 29 Khan AO, Budde BS, Nürnberg P. et al. Genome-wide linkage and sequence analysis challenge CCDC66 as a human retinal dystrophy candidate gene and support a distinct NMNAT1-related fundus phenotype. Clin Genet 2017;
• 30 Boycott KM, Rath A, Chong JX. et al. International cooperation to enable the diagnosis of all rare genetic diseases. Am J Hum Genet 2017; 100: 695-705