ABSTRACT

Background

Heterozygous c.440 G > T mutation in the S-antigen visual arrestin (SAG) gene has been described as a cause of autosomal dominant retinitis pigmentosa (adRP) in a series of patients of Hispanic origin. This study presents the early and late clinical features and disease progression rates in an Australian family with SAG adRP.

Materials and methods

An observational case series of four family members with adRP. They were examined clinically, with multi-modal retinal imaging and electroretinography (ERG) to ascertain phenotype. Disease progression rate was measured using optical coherence tomography (OCT) and fundus autofluorescence (FAF). A retinal dystrophy panel was used for the proband and cascade testing with targeted Sanger sequencing was conducted in other available family members.

Results

The proband presented at 36 years of age with profoundly reduced full-field ERG responses despite a sector RP phenotype. This progressed to a classic RP pattern over several decades leaving a small residual island of central visual field. The horizontal span of the residual outer nuclear layer and the area of hyperautofluorescent ring contracted at a rate of 8–11% and 9–14% per year, respectively. DNA sequencing confirmed the segregation of SAG c.440 G > T mutation with disease.

Conclusion

SAG adRP presents with a reduced full-field ERG response consistent with a rod-cone dystrophy in mid-life despite a sector RP phenotype. Centripetal progression of the disease into the macula can be tracked by OCT and FAF imaging.

中文翻译：

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由于澳大利亚家庭的 SAG c.440G>T 突变导致进行性扇形性视网膜色素变性

摘要

背景

S-抗原视觉抑制蛋白(SAG)基因中的杂合 c.440 G > T 突变已被描述为一系列西班牙裔患者常染色体显性色素性视网膜炎 (adRP) 的原因。本研究展示了一个患有SAG adRP的澳大利亚家庭的早期和晚期临床特征和疾病进展率。

材料和方法

四个具有 adRP 的家庭成员的观察性病例系列。他们通过多模式视网膜成像和视网膜电图 (ERG) 进行临床检查以确定表型。使用光学相干断层扫描 (OCT) 和眼底自发荧光 (FAF) 测量疾病进展率。先证者使用了视网膜营养不良小组，并在其他可用的家庭成员中进行了靶向 Sanger 测序的级联测试。

结果

先证者在 36 岁时就诊，尽管具有扇形 RP 表型，但全场 ERG 反应显着降低。几十年来，这发展为经典的 RP 模式，留下一个小的中央视野残余岛。残余外核层的水平跨度和超自发荧光环面积分别以每年 8-11% 和 9-14% 的速度收缩。DNA 测序证实了SAG c.440 G > T 突变与疾病的分离。

结论

尽管具有扇形 RP 表型，但SAG adRP 表现出降低的全视野 ERG 反应，与中年的视杆锥营养不良一致。可以通过 OCT 和 FAF 成像跟踪疾病向黄斑的向心进展。