Zhai Yi, Kodida Rita, Ballios Brian G
Division of Clinical and Metabolic Genetics, Department of Pediatrics, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada.
Department of Ophthalmology, Krembil Research Institute, University Health Network, 60 Leonard Avenue, Toronto, ON, M5T 0S8, Canada.
Am J Ophthalmol Case Rep. 2025 May 31;39:102360. doi: 10.1016/j.ajoc.2025.102360. eCollection 2025 Sep.
To report a patient with cone dystrophy and a striking tapetal reflex caused by a novel variant in , which was initially missed by a local retinal specialist due to inaccurate phenotyping of macular dystrophy.
A 33-year-old male patient presented with Bull's eye maculopathy and a tapetal-like reflex, confirmed via fundus examination and multimodal imaging. Initial genetic testing with a macular dystrophy panel was negative. Electroretinography showed reduced photopic responses and normal scotopic responses, supporting a diagnosis of cone dystrophy, and subsequent evaluation using an extended inherited retinal dystrophy panel identified a homozygous c.1186+2T>C variant classified as "likely pathogenic."
This case underscores the critical role of accurate phenotyping in guiding molecular genetic testing, particularly in distinguishing cone dystrophy from other macular dystrophies, and highlights the unique expertise of inherited retinal disease specialists in this process. Additionally, it further validates the possibility that the tapetal reflex is a common but previously underrecognized feature of -associated retinal dystrophies and expands the known variant spectrum of -associated disease. The presence of a tapetal reflex-previously widely associated with RPGR-associated dystrophies-highlighting the overlapping disease mechanisms and clinical presentation.
报告一例患有视锥细胞营养不良且伴有显著毯样反射的患者，该症状由一种新的变异引起，最初当地视网膜专科医生因黄斑营养不良的表型判断不准确而漏诊。
一名33岁男性患者出现靶心样黄斑病变和毯样反射，经眼底检查和多模态成像得以证实。最初使用黄斑营养不良检测板进行的基因检测结果为阴性。视网膜电图显示明视觉反应降低而暗视觉反应正常，支持视锥细胞营养不良的诊断，随后使用扩展的遗传性视网膜营养不良检测板进行评估，发现了一个纯合的c.1186+2T>C变异，被归类为“可能致病”。
该病例强调了准确表型分析在指导分子基因检测中的关键作用，尤其是在区分视锥细胞营养不良与其他黄斑营养不良方面，并突出了遗传性视网膜疾病专家在此过程中的独特专业知识。此外，它进一步证实了毯样反射可能是相关视网膜营养不良的一个常见但此前未被充分认识的特征，并扩展了相关疾病已知的变异谱。毯样反射的存在——此前广泛与RPGR相关的营养不良相关——突出了重叠的疾病机制和临床表现。
