Background: We present a longitudinal clinical characterization of PYGM-linked pattern dystrophy in an adult male patient.Materials and Methods: A patient affected by McArdle disease (glycogen storage disease type V) and homozygous for the nonsense variant PYGM c.148C>T p.(Arg50*) underwent ophthalmic examinations over a 9-year-interval, including fundus photography, fundus autofluorescence, optical coherence tomography (OCT), OCT-angiography and electroretinography (ERG).Results: At age 52, the patient was asymptomatic but yellow flecks were first observed in the macula of both eyes. This yellow flecks at the posterior pole progressed towards a pattern-like dystrophy over a 5-year-period. By fundus autofluorescence imaging the appearance of new hyperautofluorescent flecks and the extension of existing ones was observed over time. Concomitantly, a slow progression of the size of atrophic areas was seen at the posterior pole. Scotopic ERGs were within normal limits, but photopic Flicker responses were decreased, indicating reduced cone function.Conclusions: This additional case of PYGM-linked pattern dystrophy further confirms retinopathy as a clinical phenotype associated with McArdle disease. PYGM expression pattern suggests a disease mechanism involving impaired glycogen metabolism both in the retinal pigment epithelium and in cone photoreceptors.

中文翻译：

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McArdle病相关性视网膜病变的纵向案例研究和表型多峰表征：病理机制的见解。

背景：我们在成年男性患者中呈现PYGM相关型模式营养不良的纵向临床特征。材料与方法：一名患有McArdle病（糖原贮积病V型）且纯合子无意义变异PYGM c.148C> T p的患者（Arg50 *）进行了为期9年的眼科检查，包括眼底照相，眼底自发荧光，光学相干断层扫描（OCT），OCT血管造影和脑电图（ERG）。结果：患者52岁无症状，但首先在两只眼睛的黄斑中观察到黄色斑点。在后极的黄色斑点在5年内逐渐发展为类似模式的营养不良。通过眼底自发荧光成像，随着时间的推移，观察到了新的超自发荧光斑点的出现和现有斑点的扩展。同时，在后极观察到萎缩区大小的缓慢发展。暗视ERGs在正常范围内，但视物闪烁反应减弱，表明视锥细胞功能降低。结论：这种与PYGM相关的模式营养不良的病例进一步证实了视网膜病变是与McArdle病相关的临床表型。PYGM的表达模式提示一种疾病机制，涉及视网膜色素上皮和视锥细胞感光细胞糖原代谢受损。这种与PYGM相关的模式营养不良的额外病例进一步证实了视网膜病变是与McArdle疾病相关的临床表型。PYGM的表达模式提示一种疾病机制，涉及视网膜色素上皮和视锥细胞感光细胞糖原代谢受损。这种与PYGM相关的模式营养不良的额外病例进一步证实了视网膜病变是与McArdle疾病相关的临床表型。PYGM的表达模式提示一种疾病机制，涉及视网膜色素上皮和视锥细胞感光细胞糖原代谢受损。