TY - JOUR
T1 - Advantage of whole exome sequencing over allele-specific and targeted segment sequencing in detection of novel TULP1 mutation in leber congenital amaurosis
AU - Guo, Yiran
AU - Prokudin, Ivan
AU - Yu, Cong
AU - Liang, Jinlong
AU - Xie, Yi
AU - Flaherty, Maree
AU - Tian, Lifeng
AU - Crofts, Stephanie
AU - Wang, Fengxiang
AU - Snyder, James
AU - Donaldson, Craig
AU - Abdel-Magid, Nada
AU - Vazquez, Lyam
AU - Keating, Brendan
AU - Hakonarson, Hakon
AU - Wang, Jun
AU - Jamieson, Robyn V.
PY - 2015
Y1 - 2015
N2 - Background: Leber congenital amaurosis (LCA) is a severe form of retinal dystrophy with marked underlying genetic heterogeneity. Until recently, allele-specific assays and Sanger sequencing of targeted segments were the only available approaches for attempted genetic diagnosis in this condition. A broader next-generation sequencing (NGS) strategy, such as whole exome sequencing, provides an improved molecular genetic diagnostic capacity for patients with these conditions.Materials and Methods: In a child with LCA, an allele-specific assay analyzing 135 known LCA-causing variations, followed by targeted segment sequencing of 61 regions in 14 causative genes was performed. Subsequently, exome sequencing was undertaken in the proband, unaffected consanguineous parents and two unaffected siblings. Bioinformatic analysis used two independent pipelines, BWA-GATK and SOAP, followed by Annovar and SnpEff to annotate the variants.Results: No disease-causing variants were found using the allele-specific or targeted segment Sanger sequencing assays. Analysis of variants in the exome sequence data revealed a novel homozygous nonsense mutation (c.1081C > T, p.Arg361) in TULP1, a gene with roles in photoreceptor function where mutations were previously shown to cause LCA and retinitis pigmentosa. The identified homozygous variant was the top candidate using both bioinformatic pipelines.Conclusions: This study highlights the value of the broad sequencing strategy of exome sequencing for disease gene identification in LCA, over other existing methods. NGS is particularly beneficial in LCA where there are a large number of causative disease genes, few distinguishing clinical features for precise candidate disease gene selection, and few mutation hotspots in any of the known disease genes.
AB - Background: Leber congenital amaurosis (LCA) is a severe form of retinal dystrophy with marked underlying genetic heterogeneity. Until recently, allele-specific assays and Sanger sequencing of targeted segments were the only available approaches for attempted genetic diagnosis in this condition. A broader next-generation sequencing (NGS) strategy, such as whole exome sequencing, provides an improved molecular genetic diagnostic capacity for patients with these conditions.Materials and Methods: In a child with LCA, an allele-specific assay analyzing 135 known LCA-causing variations, followed by targeted segment sequencing of 61 regions in 14 causative genes was performed. Subsequently, exome sequencing was undertaken in the proband, unaffected consanguineous parents and two unaffected siblings. Bioinformatic analysis used two independent pipelines, BWA-GATK and SOAP, followed by Annovar and SnpEff to annotate the variants.Results: No disease-causing variants were found using the allele-specific or targeted segment Sanger sequencing assays. Analysis of variants in the exome sequence data revealed a novel homozygous nonsense mutation (c.1081C > T, p.Arg361) in TULP1, a gene with roles in photoreceptor function where mutations were previously shown to cause LCA and retinitis pigmentosa. The identified homozygous variant was the top candidate using both bioinformatic pipelines.Conclusions: This study highlights the value of the broad sequencing strategy of exome sequencing for disease gene identification in LCA, over other existing methods. NGS is particularly beneficial in LCA where there are a large number of causative disease genes, few distinguishing clinical features for precise candidate disease gene selection, and few mutation hotspots in any of the known disease genes.
KW - Leber congenital amaurosis
KW - retinitis pigmentosa
KW - TULP1
KW - whole exome sequencing
U2 - 10.3109/13816810.2014.886269
DO - 10.3109/13816810.2014.886269
M3 - Journal article
C2 - 24547928
AN - SCOPUS:84951909062
SN - 1381-6810
VL - 36
SP - 333
EP - 338
JO - Ophthalmic Genetics
JF - Ophthalmic Genetics
IS - 4
ER -