目的:广泛的常染色体显性遗传性视网膜疾病(IRD),包括轻度黄斑型营养不良和严重的锥棒变性,与PRPH2变体(“外周病变”)相关。我们提出了一个详细的临床和分子特征的患者受周围病变,旨在扩大突变谱,并提出新的基因型-表型相关性。
方法:观察性,回顾性,案例系列。
方法:患有与分子证实的PRPH2变体相关的IRD的患者。
方法:收集每次随访的眼科检查和视网膜成像数据。标准成像协议包括光学相干断层扫描(OCT),蓝光自发荧光(BAF),近红外自发荧光(NIR-AF),和超宽视野眼底成像。通过下一代测序(NGS)用基因组方法进行遗传分析。
方法:眼科检查结果,视网膜成像,和分子遗传分析。
结果:总体而言,共鉴定出19例IRD和(可能)致病性PRPH2变异体患者.他们的演讲年龄中位数为48岁,而在74%的病例中,有症状的疾病发作在30多岁或40多岁。中位随访时间为4年。临床上,6例患者被诊断为锥杆营养不良,13例被诊断为模式营养不良。在我们队列中确定的13种PRPH2致病变体中,七是错觉,3废话,2帧移位,和1个拼接位点。D2环中的错觉变异与视锥棒营养不良和不良的视力预后相关。而预测功能丧失的等位基因与模式营养不良和保持良好的视觉功能到成年期。七个变体是新颖的,从未与临床表型相关:c.68delT,c.290G>A,c.413T>G,c.642C>G,c.702_706dupCAGTT,c.771_772delinsGA,c.850C>G.
结论:此处,我们报告了一个回顾性病例系列的发现,该系列病例提供了19例患者的详细临床和分子特征,这些患者有13种不同的PRPH2致病变异,其中7个以前没有报告过,扩大了PRPH2基因的突变谱。功能丧失变异可能优先与轻度模式营养不良相关,而错义显性阴性变异与严重致盲锥杆变性相关。需要进一步的研究来更好地定义大多数变异的致病机制和功能效应。以便开发成功的基因疗法。
A broad spectrum of autosomal-dominant inherited retinal diseases (IRDs), ranging from mild macular pattern dystrophy to severe cone-rod degeneration, is associated with PRPH2 variants (peripherinopathies). We present detailed clinical and molecular characterization of patients affected by peripherinopathies, aiming to expand the mutational spectrum, and propose novel genotype-phenotype correlations.
Observational, retrospective case series.
Patients with an IRD related to a molecularly proven PRPH2 variant.
Data from ophthalmic examinations and retinal imaging were collected for each follow-up visit. The standard imaging protocol included OCT, blue-light autofluorescence, near-infrared autofluorescence, and ultra-widefield fundus imaging. Genetic analysis was performed with a genomic approach by next-generation sequencing.
Results of ophthalmic examination, retinal imaging, and molecular genetic analysis.
Overall, a total of 19 patients with an IRD and a (likely) pathogenic PRPH2 variant were identified. Their age at presentation had a median of 48 years, whereas the symptomatic disease onset was in their 30s or 40s in 74% of cases. The median follow-up time was 4 years. Clinically, 6 patients were diagnosed with cone-rod dystrophy and 13 with pattern dystrophy. Among the 13 PRPH2 pathogenic variants identified in our cohort, 7 were missense, 3 nonsense, 2 frame shifting, and 1 splice site. Missense variants in the D2 loop were associated with cone-rod dystrophies and poor visual prognosis, whereas predicted loss-of-function alleles with pattern dystrophies and retention of a good visual function into adulthood. Overall, the following 7 variants were novel and never associated to a clinical phenotype: c.68delT, c.290G>A, c.413T>G, c.642C>G, c.702_706dupCAGTT, c.771_772delinsGA, and c.850C>G.
Here, we report the findings of a retrospective case series that provided a detailed clinical and molecular characterization of 19 patients harboring 13 different PRPH2 pathogenic variants, 7 of which were previously unreported, expanding the mutational spectrum of the PRPH2 gene. Loss-of-function variants might be preferentially associated with mild-pattern dystrophies, whereas missense dominant-negative variants might be preferentially associated with severely blinding cone-rod degenerations. Further studies are needed to better define the pathogenetic mechanisms and the functional effects of most variants to allow the development of successful gene therapy.
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