Purpose

Galloway–Mowat syndrome (GAMOS) is a clinically heterogenous and rare condition classically described as the combination of nephrotic syndrome associated with brain anomaly and delays in development. It was first reported in the literature in 1968 by Galloway W.H and Mowat A.P. Reports of visual anomaly in these patients are generally limited to decreased visual acuity, nystagmus and optic nerve atrophy. To this day, little is known about retinal function in this disease. Therefore, the purpose of this case report is to reveal abnormal retinal function (including light-adapted and dark-adapted retinal function) in a female patient diagnosed with GAMOS due to mutation of the WDR73 gene.

Methods

Complete dilated pediatric ophthalmic examination and ISCEV full field standard light (10 min of light adaptation; background light: 30 cd.m⁻²; flash intensity: 3.0 cd.sec.m⁻²) and dark-adapted (20 min of dark adaptation; flash intensities: 0.01, 3.0 and 10.0 cd.sec.m⁻²) electroretinograms were performed on a 2-year-old female patient diagnosed with GAMOS due to a biallelic mutation in the WDR73 gene.

Results

Ophthalmologic evaluation under anesthesia revealed normal appearing anterior segments. Significant bilateral optic nerve pallor was noted. Fundus examination appeared to be abnormal and demonstrated mid-peripheral whitish glistening appearance with possible gliosis. Retinoscopy revealed bilateral high myopia with a refractive error of -8.00 sphere in both eyes. ISCEV standard ERG revealed residual responses under light-adapted condition. Undetectable responses were obtained after 20 min of dark adaptation when using a dim flash (DA 0.01). However, when brighter flashes were used in a dark-adapted condition (DA 3.0 and DA 10.0), the ERGs were detectable, albeit abnormal in amplitudes and of electronegative morphology.

Conclusions

The results obtained showed significant retinal functional deficit affecting both the cone and the rod photoreceptor pathways, along with the inner retina, in a patient diagnosed with GAMOS due to biallelic mutations in the WDR73 gene. Our report is limited to one patient, and additional studies are needed to verify whether retinal functional anomalies, as measured by the full field electroretinogram, present a novel biomarker in all patients affected with GAMOS or only in patients with a mutation in the WDR73 gene. Given the evidence of retinal functional changes presented in this study, it is strongly suggested to include complete ophthalmic examination, retinal imaging, including OCT, and full field ERG testing in patients affected with GAMOS.

中文翻译：

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一名诊断为 Galloway-Mowat 综合征的患者表现为视杆-视锥细胞功能异常以及电负性暗适应 ERG

目的

Galloway-Mowat 综合征 (GAMOS) 是一种临床上异质且罕见的疾病，通常被描述为与脑异常和发育迟缓相关的肾病综合征的组合。1968 年 Galloway WH 和 Mowat AP 首次在文献中报道了这些患者的视觉异常，一般仅限于视力下降、眼球震颤和视神经萎缩。时至今日，人们对这种疾病的视网膜功能知之甚少。因此，本病例报告的目的是揭示因WDR73基因突变而诊断为GAMOS的女性患者的视网膜功能异常（包括光适应和暗适应视网膜功能）。

方法

完全散瞳的儿科眼科检查和 ISCEV 全视野标准光（10 分钟的光适应；背景光：30 cd.m ^-2；闪光强度：3.0 cd.sec.m ^-2）和暗适应（20 分钟的暗适应） ；闪光强度：0.01、3.0 和 10.0 cd.sec.m ^-2 ) 对一名因 WDR73 基因的双等位基因突变而被诊断患有 GAMOS 的 2 岁女性患者进行了视网膜电图检查。

结果

麻醉下的眼科评估显示前段外观正常。注意到显着的双侧视神经苍白。眼底检查似乎异常，并显示出中周边发白的闪光外观，可能有神经胶质增生。视网膜检查显示双侧高度近视，双眼屈光不正为-8.00 球体。ISCEV 标准 ERG 揭示了光适应条件下的残余反应。当使用昏暗的闪光灯 (DA 0.01) 时，在暗适应 20 分钟后获得无法检测到的响应。然而，当在暗适应条件下（DA 3.0 和 DA 10.0）使用更亮的闪光时，可以检测到 ERG，尽管振幅和电负性形态异常。

结论

获得的结果显示，由于 WDR73 基因的双等位基因突变，在被诊断患有 GAMOS 的患者中，显着的视网膜功能缺陷影响视锥细胞和视杆细胞光感受器通路，以及视网膜内部。我们的报告仅限于一名患者，需要进行更多研究来验证视网膜功能异常（通过全视场视网膜电图测量）是否在所有受 GAMOS 影响的患者或仅在 WDR73 基因突变患者中呈现出一种新的生物标志物。鉴于本研究中提供的视网膜功能变化的证据，强烈建议对受 GAMOS 影响的患者进行完整的眼科检查、视网膜成像（包括 OCT）和全视野 ERG 测试。