Duncan Jacque L, Biswas Pooja, Kozak Igor, Navani Mili, Syed Reema, Soudry Shiri, Menghini Moreno, Caruso Rafael C, Jeffrey Brett G, Heckenlively John R, Reddy G Bhanuprakash, Lee Pauline, Roorda Austin, Ayyagari Radha
a Department of Ophthalmology , University of California , San Francisco , CA , USA .
b Shiley Eye Center, University of California , San Diego , La Jolla , CA , USA .
Ophthalmic Genet. 2016;37(1):44-52. doi: 10.3109/13816810.2014.929716. Epub 2014 Jul 9.
Characterization of retinal degeneration (RD) using high-resolution retinal imaging and exome sequencing may identify phenotypic features that correspond with specific genetic defects.
Six members from a non-consanguineous Indian family (three affected siblings, their asymptomatic parents and an asymptomatic child) were characterized clinically, using visual acuity, perimetry, full-field electroretinography (ERG), optical coherence tomography and cone structure as outcome measures. Cone photoreceptors were imaged in the proband using adaptive optics scanning laser ophthalmoscopy. The exome was captured using Nimblegen SeqCap EZ V3.0 probes and sequenced using lllumina HiSeq. Reads were mapped to reference hg19. Confirmation of variants and segregation analysis was performed using dideoxy sequencing.
Analysis of exome variants using exomeSuite identified five homozygous variants in four genes known to be associated with RD. Further analysis revealed a homozygous nonsense mutation, c.1105 C > T, p.Arg335Ter, in the FAM161A gene segregating with RD. Three additional variants were found to occur at high frequency. Affected members showed a range of disease severity beginning at different ages, but all developed severe visual field and outer retinal loss.
Exome analysis revealed a nonsense homozygous mutation in FAM161A segregating with RD with severe vision loss and a range of disease onset and progression. Loss of outer retinal structures demonstrated with high-resolution retinal imaging suggests FAM161A is important for normal photoreceptor structure and survival. Exome sequencing may identify causative genetic variants in autosomal recessive RD families when other genetic test strategies fail to identify a mutation.
使用高分辨率视网膜成像和外显子组测序对视网膜变性（RD）进行特征分析，可能会识别出与特定基因缺陷相对应的表型特征。
对一个非近亲结婚的印度家庭的六名成员（三名患病兄弟姐妹、他们无症状的父母和一名无症状儿童）进行临床特征分析，采用视力、视野检查、全视野视网膜电图（ERG）、光学相干断层扫描和视锥结构作为观察指标。使用自适应光学扫描激光检眼镜对先证者的视锥光感受器进行成像。使用Nimblegen SeqCap EZ V3.0探针捕获外显子组，并使用Illumina HiSeq进行测序。将读数映射到参考基因组hg19。使用双脱氧测序法进行变异确认和分离分析。
使用exomeSuite分析外显子组变异，在四个已知与RD相关的基因中鉴定出五个纯合变异。进一步分析发现，FAM161A基因中存在一个纯合无义突变，c.1105 C>T，p.Arg335Ter，与RD共分离。另外还发现三个高频变异。患病成员表现出不同年龄开始的一系列疾病严重程度，但均出现严重的视野缺损和视网膜外层丧失。
外显子组分析揭示了FAMl61A基因中的一个无义纯合突变，与严重视力丧失以及一系列疾病发作和进展的RD共分离。高分辨率视网膜成像显示的视网膜外层结构丧失表明FAM161A对正常光感受器结构和存活很重要。当其他基因检测策略未能识别出突变时，外显子组测序可能会识别常染色体隐性RD家族中的致病基因变异。
