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Comparison study of whole exome sequencing and targeted panel sequencing in molecular diagnosis of inherited retinal dystrophies
Received date: 2018-11-27
Online published: 2020-10-15
Supported by
National Natural Science Foundation of China(81470666);National Natural Science Foundation of China(81770966)
Objective: To evaluate and compare whole exome sequencing (WES) and targeted panel sequencing in the clinical molecular diagnosis of the Chinese families affected with inherited retinal dystrophies (IRDs). Methods: The clinical information of 182 probands affected with IRDs was collected, including their family history and the ophthalmic examination results. Blood samples of all probands and their relatives were collected and genomic DNA was extracted by standard protocols. The first 91 cases were subjected to the WES and the other 91 cases were subjected to a specific hereditary eye disease enrichment panel (HEDEP) designed by us. All likely pathogenic and pathogenic variants in the candidate genes were determined by Sanger sequencing and co-segregation analyses were performed in available family members. Copy number variations (CNVs) detected by HEDEP were further validated by multiplex ligation-dependent probe amplification (MLPA). As PRGR ORF15 was difficult to capture by next generation sequencing (NGS), all the samples were subjected to Sanger sequencing for this region. All sequence changes identified by NGS were classified according to the American College of Medical Gene-tics and Genomics and the Association for Molecular Pathology (ACMG/AMP) variant interpretation guidelines. In this study, only variants identified as pathogenic or likely pathogenic were included, while those variants of uncertain significance, likely benign or benign were not included. Results: In 91 cases with WES, pathogenic or likely pathogenic variants were determined in 30 cases, obtaining a detection rate of 33.00% (30/91); While in 91 cases with HEDEP sequencing, pathogenic or likely pathogenic variants were determined in 51 cases, achieving the diagnostic rate of 56.04% (51/91), and totally, the diagnostic rate was 44.51%. HEDEP had better sequencing coverage and read depth than WES, therefore HEDEP had higher detection rate. In addition, HEDEP could detect CNVs. In this study, we detected disease-causing variants in 29 distinct IRD-associated genes, USH2A, ABCA4 and RPGR were the three most common disease-causing genes, and the frequency of these genes in Chinese IRDs population was 11.54% (21/182), 6.59% (12/182) and 3.85% (7/182), respectively. We found 43 novel variants and 6 cases carried variants in RPGR ORF15. Conclusion: NGS in conjunction with Sanger sequencing offers a reliable and effective approach for the genetic diagnosis of IRDs, and after evaluating the pros and cons of the two sequencing methods, we conclude that HEDEP should be used as a first-tier test for IRDs patients, WES can be used as a supplementary molecular diagnostic method due to its merit of detecting novel IRD-associated genes if HEDEP or other methods could not detect disease-causing va-riants in reported genes. In addition, our results enriched the mutational spectra of IRDs genes, and our methods paves the way of genetic counselling, family planning and up-coming gene-based therapies for these families.
Xiao-zhen LIU , Ying-ying LI , Li-ping YANG . Comparison study of whole exome sequencing and targeted panel sequencing in molecular diagnosis of inherited retinal dystrophies[J]. Journal of Peking University(Health Sciences), 2020 , 52(5) : 836 -844 . DOI: 10.19723/j.issn.1671-167X.2020.05.007
| [1] | Berger W, Kloeckener-Gruissem B, Neidhardt J. The molecular basis of human retinal and vitreoretinal diseases[J]. Prog Retin Eye Res, 2010,29(5):335-375. |
| [2] | Zhao L, Wang F, Wang H, et al. Next-generation sequencing-based molecular diagnosis of 82 retinitis pigmentosa probands from Northern Ireland[J]. Hum Genet, 2015,134(2):217-230. |
| [3] | Glockle N, Konl LS, Mohr J, et al. Panel-based next generation sequencing as a reliable and efficient technique to detect mutations in unselected patients with retinal dystrophies[J]. Eur J Hum Genet, 2014,22(1):99-104. |
| [4] | Beryozkin A, Shevah E, Kimchi A, et al. Whole exome sequencing reveals mutations in known retinal disease genes in 33 out of 68 Israeli families with inherited retinopathies[J]. Sci Rep, 2015(5):13187. |
| [5] | Yang L, Cui H, Yin X, et al. Dependable and efficient clinical molecular diagnosis of Chinese RP patient with targeted exon sequencing[J]. PLoS One, 2015,10(10):e0140684. |
| [6] | Riera M, Navarro R, Ruiz-Nogales S, et al. Whole exome sequencing using Ion Proton system enables reliable genetic diagnosis of inherited retinal dystrophies[J]. Sci Rep, 2017(7):42078. |
| [7] | Zhang J, Wang C, Shen Y, et al. A mutation in ADIPOR1 causes nonsyndromic autosomal dominant retinitis pigmentosa[J]. Hum Genet, 2016,135(12):1375-1387. |
| [8] | Bader I, Brandau O, Achatz H, et al. X-linked retinitis pigmentosa: RPGR mutations in most families with definite X linkage and clustering of mutations in a short sequence stretch of exon ORF15[J]. Invest Ophthalmol Vis Sci, 2003,44(4):1458-1463. |
| [9] | Li L, Xiao X, Li S, et al. Detection of variants in 15 genes in 87 unrelated Chinese patients with Leber congenital amaurosis[J]. PLoS One, 2011,6(5):e19458. |
| [10] | Xiao X, Mai G, Li S, et al. Identification of CYP4V2 mutation in 21 families and overview of mutation spectrum in Bietti crystalline corneoretinal dystrophy[J]. Biochem Biophys Res Commun, 2011,409(2):181-186. |
| [11] | Li A, Jiao X, Munier FL, et al. Bietti crystalline corneoretinal dystrophy is caused by mutations in the novel gene CYP4V2[J]. Am J Hum Genet, 2004,74(5):817-826. |
| [12] | Consugar MB, Navarro-Gomez D, Place EM, et al. Panel-based genetic diagnostic testing for inherited eye diseases is highly accurate and reproducible, and more sensitive for variant detection, than exome sequencing[J]. Genet Med, 2015,17(4):253-261. |
| [13] | Bujakowska KM, Fernandez-Godino R, Place E, et al. Copy-number variation is an important contributor to the genetic causality of inherited retinal degenerations[J]. Genet Med, 2017,19(6):643-651. |
| [14] | Haer-Wigman L, van Zelst-Stams WA, Pfundt R, et al. Diagnostic exome sequencing in 266 Dutch patients with visual impairment[J]. Eur J Hum Genet, 2017,25(5):591-599. |
| [15] | Broadgate S, Yu J, Downes SM, et al. Unravelling the genetics of inherited retinal dystrophies: Past, present and future[J]. Prog Retin Eye Res, 2017(59):53-96. |
| [16] | 周雪莹, 于志强. 全基因组外显子测序在眼科遗传病中的应用[J]. 中华眼科杂志, 2015,51(5):395-400. |
| [17] | ACMG Board of Directors Points to consider in the clinical application of genomic sequencing[J]. Genet Med, 2012,14(8):759-761. |
| [18] | Yuzawa M, Mae Y, Matsui M. Bietti’s crystalline retinopathy[J]. Ophthalmic Paediatr Genet, 1986,7(1):9-20. |
| [19] | Lee KY, Koh AH, Aung T, et al. Characterization of Bietti crystalline dystrophy patients with CYP4V2 mutations[J]. Invest Ophthalmol Vis Sci, 2005,46(10):3812-3816. |
| [20] | Tiwari A, Lemke J, Altmueller J, et al. Identification of novel and recurrent disease-causing mutations in retinal dystrophies using whole exome sequencing (WES): Benefits and limitations[J]. PLoS One, 2016,11(7):e0158692. |
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