Department of Ophthalmology, The Jikei University School of Medicine, Tokyo, 105-8461, Japan.
Department of Ophthalmology, Katsushika Medical Center, The Jikei University School of Medicine, 6-41-2 Aoto, Katsushika-Ku, Tokyo, 125-8506, Japan.
Doc Ophthalmol. 2023 Aug;147(1):59-70. doi: 10.1007/s10633-023-09936-9. Epub 2023 May 25.
Biallelic variants in POC1B are rare causes of autosomal recessive cone dystrophy associated with generalized cone system dysfunction. In this report, we describe the clinical characteristics of a Japanese male patient with POC1B-associated retinopathy with relatively preserved cone system function.
We performed whole-exome sequencing (WES) to identify the disease-causing variants and a comprehensive ophthalmic examination, including full-field and multifocal electroretinography (ffERG and mfERG).
Our WES analysis identified novel compound heterozygous POC1B variants (p.Arg106Gln and p.Arg452Ter) in the patient. His unaffected mother carried the p.Arg452Ter variant heterozygously. The patient experienced decreased visual acuity in his 50s. At the age of 63, his corrected visual acuity was 20/22 in the right and 20/20 in the left eye. Fundus and fundus autofluorescence images for each eye showed no remarkable finding, except for a subtle hyperautofluorescent spot in the fovea of the left eye. Cross-sectional optical coherence tomography demonstrated blurred but a relatively preserved ellipsoid zone. The ffERG showed that amplitudes of rod and standard-flash responses were within the reference range, whereas the cone and light-adapted 30-Hz flicker amplitudes were close to, or slightly below, the reference range. The mfERG revealed substantially reduced responses with relative preservation of central function.
We reported the case of an older patient with POC1B-associated retinopathy, demonstrating late-onset visual decrease, good visual acuity, and relatively preserved cone system function. The disease condition was much milder than previously reported in patients with POC1B-associated retinopathy.
POC1B 的双等位基因突变是常染色体隐性遗传 cone 变性伴全 cone 系统功能障碍的罕见病因。本报告描述了一位具有 POC1B 相关性视网膜病变的日本男性患者的临床特征，其 cone 系统功能相对保存。
我们进行了全外显子组测序（WES）以鉴定致病变异，并进行了全面的眼科检查，包括全视野和多焦点视网膜电图（ffERG 和 mfERG）。
我们的 WES 分析在该患者中发现了 novel 复合杂合 POC1B 变异（p.Arg106Gln 和 p.Arg452Ter）。他未受影响的母亲为 p.Arg452Ter 变异杂合子携带者。该患者在 50 多岁时出现视力下降。在 63 岁时，他的右眼矫正视力为 20/22，左眼为 20/20。双眼的眼底和眼底自发荧光图像除左眼黄斑区有一个细微的高自发荧光点外，均未见明显异常。横断面光学相干断层扫描显示，椭圆体带模糊但相对保存。ffERG 显示 rod 和标准闪光反应的振幅均在参考范围内，而 cone 和光适应 30-Hz 闪烁振幅接近或略低于参考范围。mfERG 显示中央功能相对保存，但反应明显降低。
我们报告了一例 POC1B 相关性视网膜病变的老年患者，表现为发病较晚的视力下降、良好的视力和相对保存的 cone 系统功能。该患者的疾病状况比先前报道的 POC1B 相关性视网膜病变患者明显较轻。
