Background

Little is known about whether patients with complete congenital stationary night blindness (CSNB) maintain visual function throughout their lifetime. The purpose of this report was to describe clinical and genetic features of an elderly female patient with complete CSNB that we followed for 5 years.

Methods

Molecular genetic analysis using whole-exome sequencing (WES) was performed to detect disease-causing variants. We performed a comprehensive ophthalmic examination including full-field electroretinography (ERG).

Results

In the patient, WES identified two novel variants (c.1034delT; p.Phe345SerfsTer16 and c.1880T>A; p.Met627Lys) in the TRPM1 gene. Her unaffected daughter has one of the variants. The patient reported that her visual acuity has remained unchanged since elementary school. At the age of 68 years old, fundus and fundus autofluorescence imaging showed no remarkable findings except for mild myopic changes. Goldmann perimetry showed preserved visual fields with all V-4e, I-4e, I-3e and I-2e isopters. Optical coherence tomography demonstrated preserved retinal thickness and lamination. Rod ERG showed no response; bright-flash ERG showed an electronegative configuration with minimally reduced a-waves, and cone and 30-Hz flicker ERG showed minimally reduced responses. Overall, the ERG findings of ON bipolar pathway dysfunction were consistent with complete CSNB.

Conclusions

This is the oldest reported patient with complete CSNB and biallelic TRPM1 variants. Our ophthalmic findings suggest that some patients with TRPM1-related CSNB may exhibit preserved retinal function later in life.

中文翻译：

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患有完全先天性静止性夜盲症的老年患者的新型双等位基因 TRPM1 变体

背景

对于完全先天性静止性夜盲症 (CSNB) 患者是否在其一生中保持视觉功能知之甚少。本报告的目的是描述我们跟踪了 5 年的患有完全性 CSNB 的老年女性患者的临床和遗传特征。

方法

使用全外显子组测序 (WES) 进行分子遗传分析以检测致病变异。我们进行了全面的眼科检查，包括全视野视网膜电图 (ERG)。

结果

在该患者中，WES 在 TRPM1 中发现了两个新的变体（c.1034delT；p.Phe345SerfsTer16 和 c.1880T>A；p.Met627Lys ）基因。她未受影响的女儿有其中一种变异。患者报告她的视力自小学以来一直保持不变。68岁时，眼底和眼底自体荧光成像除轻度近视改变外，无明显发现。Goldmann 视野检查显示所有 V-4e、I-4e、I-3e 和 I-2e 等轴器的视野都保留。光学相干断层扫描显示保留的视网膜厚度和分层。Rod ERG 没有反应；明亮闪光 ERG 显示出具有最小减少的 a 波的电负性配置，并且锥形和 30-Hz 闪烁 ERG 显示最小减少的响应。总体而言，ON 双极通路功能障碍的 ERG 发现与完全 CSNB 一致。

结论

这是报告的最老的具有完整 CSNB 和双等位基因TRPM1变体的患者。我们的眼科研究结果表明，一些患有TRPM1相关 CSNB 的患者可能在以后的生活中表现出保留的视网膜功能。