PDF(Pubmed)
Abstract：
The retinal features of Bardet-Biedl syndrome (BBS) are insufficiently characterized in Arab populations. This retrospective study investigated the retinal features and genotypes of BBS in Saudi patients managed at a single tertiary eye care center. Data analysis of the identified 46 individuals from 31 families included visual acuity (VA), systemic manifestations, multimodal retinal imaging, electroretinography (ERG), family pedigrees, and genotypes. Patients were classified to have cone-rod, rod-cone, or generalized photoreceptor dystrophy based on the pattern of macular involvement on the retinal imaging. Results showed that nyctalopia and subnormal VA were the most common symptoms with 76% having VA ≤ 20/200 at the last visit (age: 5-35). Systemic features included obesity 91%, polydactyly 56.5%, and severe cognitive impairment 33%. The predominant retinal phenotype was cone-rod dystrophy 75%, 10% had rod-cone dystrophy and 15% had generalized photoreceptor dystrophy. ERGs were undetectable in 95% of patients. Among the 31 probands, 61% had biallelic variants in BBSome complex genes, 32% in chaperonin complex genes, and 6% had biallelic variants in ARL6; including six previously unreported variants. Interfamilial and intrafamilial variabilities were noted, without a clear genotype-phenotype correlation. Most BBS patients had advanced retinopathy and were legally blind by early adulthood, indicating a narrow therapeutic window for rescue strategies.
摘要：
在阿拉伯人群中，Bardet-Biedl综合征（BBS）的视网膜特征不足。这项回顾性研究调查了在一个三级眼科护理中心管理的沙特患者的视网膜特征和BBS基因型。对来自31个家庭的46个个体的数据分析包括视敏度（VA），系统性表现，多模态视网膜成像，视网膜电图（ERG），家庭血统,和基因型。患者被分类为锥形杆，棒锥,或基于视网膜成像的黄斑受累模式的全身性光感受器营养不良。结果显示，斜视和低于正常的VA是最常见的症状，在最后一次就诊时（年龄：5-35），有76％的VA≤20/200。系统性特征包括肥胖91%，多指56.5%，和严重的认知障碍33%。主要的视网膜表型是75％的视锥细胞营养不良，10％患有视锥细胞营养不良，15％患有全身性光感受器营养不良。95%的患者无法检测到ERGs。在31名先证者中，61%的人在BBSome复杂基因中有双等位基因变异，32％的伴侣复合基因，6％的人在ARL6中具有双等位基因变异;包括6种以前未报告的变异。注意到家族间和家族内变异，没有明确的基因型-表型相关性。大多数BBS患者患有晚期视网膜病变，并且在成年早期是合法失明的，表明救援策略的治疗窗口狭窄。
