Department of Ophthalmology, Pathology and Cell Biology, Columbia University Irving Medical Center, New York, NY, USA.
Jonas Children's Vision Care and Bernard and Shirlee Brown Glaucoma Laboratory, New York-Presbyterian Hospital, New York, NY, USA.
Doc Ophthalmol. 2023 Jun;146(3):267-272. doi: 10.1007/s10633-022-09916-5. Epub 2023 Jan 7.
Mutations in the peripherin-2 gene (PRPH2) are a common cause of inherited retinal dystrophies well known for their phenotypic diversity. We describe a novel presentation of the c.623G > A; p.(Gly208Asp) variant in association with cone-rod dystrophy and reduced penetrance.
A 39-year-old man presents with a history of decreased visual acuity, photophobia, and dyschromatopsia. Fundus examination was largely unremarkable while spectral-domain optical coherence tomography (SD-OCT) demonstrated diffuse granularity at the ellipsoid zone. Full-field electroretinogram (ffERG) revealed a cone-rod dystrophy. Genetic testing revealed a heterozygous pathogenic variant, c.623G > A; p.(Gly208Asp), in the PRPH2 gene, also found in an unaffected brother. The 50-year-old brother had no visual symptoms and no findings on fundus examination. SD-OCT showed normal retinal architecture and ffERG was within normal limits bilaterally.
This case report broadens the known phenotypic presentations of PRPH2-associated retinopathy and suggests that the PRPH2 variant c.623G > A; p.(Gly208Asp) may be associated with reduced penetrance.
外周蛋白-2 基因（PRPH2）的突变是常见的遗传性视网膜疾病的病因，其表型多样性是众所周知的。我们描述了一种与 Cone-Rod 营养不良和外显率降低相关的新型 c.623G > A;p.(Gly208Asp)变异。
一名 39 岁男性出现视力下降、畏光和色觉障碍病史。眼底检查大体正常，而频域光相干断层扫描（SD-OCT）显示在椭圆体带弥漫性颗粒状。全视野视网膜电图（ffERG）显示 Cone-Rod 营养不良。基因检测显示 PRPH2 基因存在杂合致病性变异 c.623G > A;p.(Gly208Asp)，该变异也存在于一位未受影响的兄弟中。这位 50 岁的兄弟没有视觉症状，眼底检查也没有发现异常。SD-OCT 显示视网膜结构正常，ffERG 双侧均在正常范围内。
本病例报告拓宽了 PRPH2 相关视网膜病变的已知表型表现，并提示 PRPH2 变异 c.623G > A;p.(Gly208Asp)可能与外显率降低有关。
