Hayashi Takaaki, Goto-Omoto Satoshi, Takeuchi Tomokazu, Gekka Tamaki, Ueoka Yasuo, Kitahara Kenji
Department of Ophthalmology, Jikei University School of Medicine, Tokyo, Japan.
Acta Ophthalmol Scand. 2006 Apr;84(2):254-8. doi: 10.1111/j.1600-0420.2005.00575.x.
To describe the clinical features and genetic analysis of a 3-year-old boy diagnosed with familial fleck retina with night blindness.
The proband and his parents and grandparents were included. History, visual acuity and fundus examinations were evaluated. Bright-flash (rod-plus-cone) electroretinograms (ERGs) were recorded after 30 mins and 180 mins of dark adaptation. Mutation screening of the RDH5 gene encoding 11-cis retinol dehydrogenase was performed.
The parents noticed the proband's night blindness when he was 2 years old. Best corrected visual acuity was 1.0 in both eyes. Fundus examinations revealed numerous yellow-white flecks of varying size and shape throughout the midperipheral to far peripheral retina in both eyes. The distribution, size and shape of the flecks were comparable to those seen in familial fleck retina with night blindness, rather than fundus albipunctatus. The ERGs showed extremely diminished responses after 30 mins of dark adaptation, but there were substantial increases in the amplitudes of both a- and b-waves when recorded after 180 mins of dark adaptation. Although a total of 19 RDH5 mutations have been found only in patients with fundus albipunctatus, compound heterozygous mutations, p.V177G and p.L310delinsEV, whose combination has not been previously reported, were found in the proband. The asymptomatic parents and one of the grandparents each carried one of the mutations, consistent with autosomal recessive transmission.
Our study indicates that different mutations in the RDH5 gene can cause phenotypic variations of either fundus albipunctatus or familial fleck retina with night blindness.
描述一名被诊断为家族性斑点状视网膜伴夜盲症的3岁男孩的临床特征及基因分析。
纳入先证者及其父母和祖父母。评估病史、视力和眼底检查。在暗适应30分钟和180分钟后记录明闪光（视杆 - 视锥）视网膜电图（ERG）。对编码11 - 顺式视黄醇脱氢酶的RDH5基因进行突变筛查。
父母在患儿2岁时注意到其夜盲症。双眼最佳矫正视力均为1.0。眼底检查显示双眼从中周部到远周边视网膜有许多大小和形状各异的黄白色斑点。这些斑点的分布、大小和形状与家族性斑点状视网膜伴夜盲症所见相似，而非白点状眼底。ERG显示暗适应30分钟后反应极度减弱，但暗适应180分钟后记录时a波和b波的振幅均有显著增加。虽然仅在白点状眼底患者中发现了总共19种RDH5突变，但在先证者中发现了复合杂合突变p.V177G和p.L310delinsEV，其组合此前未见报道。无症状的父母和一位祖父母各自携带其中一种突变，符合常染色体隐性遗传。
我们的研究表明，RDH5基因的不同突变可导致白点状眼底或家族性斑点状视网膜伴夜盲症的表型变异。
