Search

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.

Background/purpose: To report a case of Stickler Type IV with familial exudative vitreoretinopathy phenotype., Methods: Retrospective case report., Results: A 24-year-old woman presented with right eye exotropia and decreased vision. She had no facial or typical retinal features of Stickler syndrome but complained of right-sided hearing loss and right-sided neck pain. Examination of the right eye showed a chronic combined exudative and traction retinal detachment with temporal retinal dragging associated with far temporal retinal exudations and fibrovascular proliferations. The left eye had an attached retina with large areas of peripheral temporal retinal nonperfusion on fluorescein angiography, sharply demarcated by end circulation vascular pruning and mild peripheral vascular leakage, consistent with familial exudative vitreoretinopathy phenotype. Genetic analysis identified two heterozygous c.1052C>A and c.1349A>G variants in COL9A1, but did not disclose any mutation in genes classically associated with familial exudative vitreoretinopathy., Conclusion: Familial exudative vitreoretinopathy-like retinal vascular features can be the presenting sign in patients with Stickler syndrome Type IV.

Purpose: To describe the features of retinal detachments and high myopia in patients with novel pathogenic variants in LEPREL1 and report a possible association with nephropathy., Methods: Retrospective study of 10 children with biallelic LEPREL1 pathogenic variants. Data included ophthalmic features, surgical interventions, and genetic and laboratory findings., Results: 10 patients (8 females) from three families with homozygous (2) or compound heterozygous (1) variants in LEPREL1 were included. At presentation, mean age was 9.9 ± 2.6 years. Mean axial length was 28.9 ± 1.9 mm and mean refraction was -13.9 ± 2.8 diopters. Bilateral posterior subcapsular cataracts were present in eight patients (80%), with lens subluxation in five eyes of three patients (30%). Rhegmatogenous retinal detachments (RRD), associated with giant retinal tears (GRT), developed in seven eyes of five patients (50%) at a mean age of 14.14 ± 5.9 years. Six were successfully reattached with mean Snellen best-corrected visual acuity improving from 20/120 preoperatively to 20/60 at last follow-up. Urinalysis in nine patients revealed microhematuria and/or mild proteinuria in six patients (67%)., Conclusion: LEPREL1 -related high myopia confers a high risk of early-onset GRT-related RRD. The ocular phenotype may be confused with that of ocular Stickler syndrome if genetic testing is not performed. Further investigations into a potential association with renal dysfunction are warranted.