Showing papers in "Ophthalmic Genetics in 2021"

Inherited retinal diseases are the most common cause of blindness in the working-age population in Australia.

Abstract: Background: This study examined the frequency of inherited retinal diseases (IRDs) as the reason for blindness registrations over the last two decades and the demographic and clinical phenotypes of inherited retinal disease (IRD)-related registrations.Materials and methods: Retrospective, observational study of individuals registered with a state-wide blind and vision-impaired registry. Low-vision or blindness-only (≤20/200 or ≤20°) certificates issued to children (0-15 years), working-age (16-64 years) and older-age (65 and older) adults were assessed. Sex and age distributions were examined for the top 20 reasons for certification. Demographic and clinical features of specific phenotypes of IRDs listed in the registry were examined.Results: Amongst 11824 low-vision certificates issued between July 1995 and January 2017, 679 (5.7%) listed an IRD as the reason for registration. In individuals with blindness-only certification (N=4919), IRDs was the second most common diagnosis (8.3%), overtaking glaucoma (8.1%) and diabetic retinopathy (5.4%). IRD was the second most common reason for low-vision certification amongst children (11.6%) and the most common reason amongst working-age population (23.3%). The mean±SD age for IRD-related blindness-only certification was 46±20 years. The top three phenotypes of IRD-related low-vision certification were non-syndromic retinitis pigmentosa (54%), Stargardt disease (12%) and macular dystrophy (8%).Conclusion: Our findings of IRDs as a common cause of blindness in all ages justify continued funding for providing low-vision services and developing treatments for these conditions.

Stargardt disease and progress in therapeutic strategies

Abstract: Background: Stargardt disease (STGD1) is an autosomal recessive retinal dystrophy due to mutations in ABCA4, characterized by subretinal deposition of lipofuscin-like substances and bilateral centrifugal vision loss. Despite the tremendous progress made in the understanding of STGD1, there are no approved treatments to date. This review examines the challenges in the development of an effective STGD1 therapy. Materials and Methods: A literature review was performed through to June 2021 summarizing the spectrum of retinal phenotypes in STGD1, the molecular biology of ABCA4 protein, the in vivo and in vitro models used to investigate the mechanisms of ABCA4 mutations and current clinical trials.Results: STGD1 phenotypic variability remains an challenge for clinical trial design and patient selection. Pre-clinical development of therapeutic options has been limited by the lack of animal models reflecting the diverse phenotypic spectrum of STDG1. Patient-derived cell lines have facilitated the characterization of splice mutations but the clinical presentation is not always predicted by the effect of specific mutations on retinoid metabolism in cellular models. Current therapies primarily aim to delay vision loss whilst strategies to restore vision are less well developed. Conclusions: STGD1 therapy development can be accelerated by a deeper understanding of genotype-phenotype correlations.

Ocular manifestations in classic homocystinuria.

Abstract: Classic homocystinuria (HCU), or cystathionine beta-synthase (CBS) deficiency, is a rare inborn error of methionine metabolism. Main clinical features may include skeletal and vascular manifestatio...

Multimodal imaging and genetic findings in a case of ARSG-related atypical Usher syndrome.

Abstract: Background: Atypical Usher syndrome has recently been associated with arylsulfatase G (ARSG) variants. In these cases, characteristic findings include progressive sensorineural hearing loss (SNHL) ...

Expanding the clinical phenotype in patients with disease causing variants associated with atypical Usher syndrome.

Abstract: Atypical Usher syndrome (USH) is poorly defined with a broad clinical spectrum. Here, we characterize the clinical phenotype of disease caused by variants in CEP78, CEP250, ARSG, and ABHD12.Chart review evaluating demographic, clinical, imaging, and genetic findings of 19 patients from 18 families with a clinical diagnosis of retinal disease and confirmed disease-causing variants in CEP78, CEP250, ARSG, or ABHD12.CEP78-related disease included sensorineural hearing loss (SNHL) in 6/7 patients and demonstrated a broad phenotypic spectrum including: vascular attenuation, pallor of the optic disc, intraretinal pigment, retinal pigment epithelium mottling, areas of mid-peripheral hypo-autofluorescence, outer retinal atrophy, mild pigmentary changes in the macula, foveal hypo-autofluorescence, and granularity of the ellipsoid zone. Nonsense and frameshift variants in CEP250 showed mild retinal disease with progressive, non-congenital SNHL. ARSG variants resulted in a characteristic pericentral pattern of hypo-autofluorescence with one patient reporting non-congenital SNHL. ABHD12-related disease showed rod-cone dystrophy with macular involvement, early and severe decreased best corrected visual acuity, and non-congenital SNHL ranging from unreported to severe.This study serves to expand the clinical phenotypes of atypical USH. Given the variable findings, atypical USH should be considered in patients with peripheral and macular retinal disease even without the typical RP phenotype especially when SNHL is noted. Additionally, genetic screening may be useful in patients who have clinical symptoms and retinal findings even in the absence of known SNHL given the variability of atypical USH.

The haplotype of the CDKN2B-AS1 gene is associated with primary open-angle glaucoma and pseudoexfoliation glaucoma in the Caucasian population of Central Russia

Abstract: PURPOSE To replicate the finding of the association of five CDKN2B-AS1 gene polymorphisms (rs7865618, rs1063192, rs944800, rs2157719, and rs4977756) with primary open-angle glaucoma (POAG) and to analyze them for possible association with pseudoexfoliation glaucoma (PXFG) in a Caucasian population of Central Russia. METHODS A total of 932 participants of Russian ethnicity (self-reported), including 328 patients with PXFG, 208 patients with POAG (high-tension glaucoma), and 396 controls, were enrolled in the study. The SNPs were analyzed for possible associations using logistic regression. RESULTS Several haplotypes based on the studied SNPs were associated with POAG (three haplotypes) and PXFG (six haplotypes). Haplotype AAAGG of loci rs1063192-rs7865618-rs2157719-rs944800-rs4977756 conferred the highest risk for both POAG (OR = 3.99, рperm = 0.001) and PXFG (OR = 2.84, рperm = 0.001). CONCLUSIONS The CDKN2B-AS1 gene was associated with an increased risk of both POAG and PXFG in Caucasians of Central Russia. The gene may be related to the development of various types of glaucoma.

Living with Stargardt disease: insights from patients and their parents.

Abstract: Background: Stargardt disease (STGD), a rare, inherited macular degeneration most commonly affecting children and young adults, is a rapidly progressive disease leading to severe central vision los...

Exploring microperimetry and autofluorescence endpoints for monitoring disease progression in PRPF31 -associated retinopathy.

Abstract: Mutations in the splicing factor pre-messenger RNA processing factor 31 (PRPF31) gene cause autosomal dominant retinitis pigmentosa 11 (RP11) through a haplo-insufficiency mechanism. We describe th...

Current concepts on diffuse choroidal hemangioma in Sturge Weber syndrome.

Abstract: Background: Diffuse choroidal hemangioma (DCH) is a benign vascular tumor that is characteristically found in the Sturge-Weber syndrome (SWS). Recent genetic discoveries demonstrate that DCH occurs sporadically from an activating mutation in GNAQ at codon R183. Mutations in GNAQ or GNA11 result in dysregulation of the mitogen-activated protein kinase, which influences gene transcription and results in cellular proliferation. DCH may not always be readily detected on routine ophthalmological examination, consequently diagnosis and multidisciplinary referral are often delayed.Purpose: A literature search was performed through April 2020 without a lower date limit. This review will summarize the pathogenesis, diagnosis and management of DCH.Discussion: Multimodal imaging facilitates early detection of the condition. In particular, enhanced depth imaging spectral domain optical coherence tomography enables non-invasive, high-resolution visualization of the choroid to even detect mild choroidal thickening. Management of symptomatic DCH is generally difficult and results in poor visual outcome, thus, treatment is generally unwarranted, unless the hemangioma complicated by serous retinal detachment. The main treatment method is radiation therapy with external beam radiation therapy, proton beam therapy, plaque brachytherapy, and gamma knife surgery where low doses of radiation entail fewer complications. One method of alternative management is with photodynamic therapy that, although less invasive with a lower rate of complications, is not always feasible or effective in cases with extensive exudative retinal detachment.Conclusions: Multimodal ophthalmological imaging facilitates diagnosis of DCH and lifelong surveillance is essential in patients.

Complete congenital stationary night blindness associated with a novel NYX variant (p.Asn216Lys) in middle-aged and older adult patients.

Abstract: Background: Complete congenital stationary night blindness (CSNB) is a retinal disorder thought to be non-progressive. The purpose of this study was to characterize the clinical and genetic finding...

Variable expressivity in patients with autosomal recessive retinitis pigmentosa associated with the gene CNGB1

Abstract: Purpose In a cohort of eight families (11 patients) with autosomal recessive retinitis pigmentosa (arRP), we clinically characterized disease associated with mutations in CNGB1. Methods Visual function was determined by measuring the patients' visual acuity, dark- and light-adapted perimetry, and by full-field electroretinography. Retinal structure was evaluated with spectral-domain optical coherence tomography, fundus imaging, and autofluorescence imaging. Results Age of onset ranged from 4 to 49 years (mean [SD] 26 [17], median 27 years). The age at visit was 27-54 years, mean 37 (17). The range of visual acuity was logMAR -0.1 to 1.3 (Snellen 20/16 to 20/400) in the right eye and -0.1 to 0.9 (Snellen 20/16 to 20/160) in the left eye. Electrophysiological testing in five patients showed an absence of the rod response. Cone responses ranged from normal to severely reduced. The patients exhibited loss of rod vision more severe than cone vision. Funduscopic images showed widespread retinal degeneration with pigment clumping, optic disk pallor, arteriole attenuation, and a peri-foveal ring of hyper autofluorescence. Three families were tested for olfactory dysfunction and results indicated mild to complete anosmia in individuals with mutations in CNGB1. Genetic analysis revealed 6 novel variants, c.2127 C > G, p.Phe709Leu; c.1431 C > A, p.Cys477*; c.2034 G > A, p.Trp678*; c.2092 T > C, p.Cys698Arg; and c.583 + 2 T > C, c.2305-34 G > A and 3 variants that have been previously described, c.2957A>T, p.Asn986Ile; c.2544dup, p.Leu849Alafs*3; and c.2492 + 1 G > A. Discussion This is the first report for six novel CNGB1 variants associated with arRP. Two families had olfactory dysfunction in patients with arRP and family members who were heterozygous for a CNGB1 mutation. Additionally, findings demonstrated variable penetrance and expressivity of disease in these patients.

Association of relative leukocyte telomere length and genetic variants in telomere-related genes ( TERT, TERT-CLPTM1, TRF1, TNKS2, TRF2) with atrophic age-related macular degeneration

Abstract: Background: In an experimental model, telomere shortening inhibits neovascularization. It is thus possible that telomere shortening might have a role in the pathogenesis of geographic atrophy in ca...

Longitudinal phenotypic study of late-onset retinal degeneration due to a founder variant c.562C>A p.(Pro188Thr) in the C1QTNF5 gene

Abstract: Background: Late-onset retinal degeneration (L-ORD) is a rare autosomal dominant retinal dystrophy related to C1QTNF5 gene variants.Materials and methods: Twenty-six patients (21–81 years) with L-O...

Ocular manifestations in kabuki syndrome: A report of 10 cases and literature review

Abstract: Background: We investigated the ocular manifestations in patients with Kabuki syndrome(KS).Methods: A retrospective chart review was performed in 10 patients with KS were referred to the Department...

Chorioretinal dystrophy, hypogonadotropic hypogonadism, and cerebellar ataxia: Boucher-Neuhauser syndrome due to a homozygous (c.3524C>G (p.Ser1175Cys)) variant in PNPLA6 gene

Abstract: Purpose: The current study aims to raise awareness of Boucher – Neuhauser syndrome (BNHS) that occurs as a rare phenotype due to biallelic pathogenic variants in the PNPLA6 gene.Methods: Detailed f...

Clinical spectrum, genetic associations and management outcomes of Coats-like exudative retinal vasculopathy in autosomal recessive retinitis pigmentosa

Abstract: Background: Coats-like retinal vasculopathy in retinitis pigmentosa (RP) is rare. This study describes its clinical spectrum, management outcomes and genetic associations in patients with autosomal...

Ophthalmic findings and a novel CTC1 gene mutation in coats plus syndrome: a case report.

Abstract: Coats plus syndrome is a rare multisystem disorder, and is also a telomere-related disorder caused by CTC1 gene mutation. We reported ophthalmic findings in a Chinese child with genetically confirm...

Bardet-Biedl syndrome-7 (BBS7) shows treatment potential and a cone-rod dystrophy phenotype that recapitulates the non-human primate model.

Abstract: Purpose: To provide a detailed ophthalmic phenotype of two male patients with Bardet-Biedl Syndrome (BBS) due to mutations in the BBS7 geneMethods: Two brothers ages 26 (Patient 1, P1) and 23 (P2) ...

The presence and progression of choroidal neurofibromas in a predominantly pediatric population with neurofibromatosis type-1.

Abstract: Background: Obtaining a definitive neurofibromatosis type-1 (NF1) diagnosis may take years. The natural history of choroidal neurofibromas in NF1 is unknown. This study evaluates a predominantly pe...

Autosomal recessive Stickler syndrome associated with homozygous mutations in the COL9A2 gene.

Abstract: Background: Stickler syndrome is a hereditary disorder of collagen tissues causing ocular, auditory, orofacial, and joint manifestations. Ocular findings typically include vitreous degeneration, high myopia, retinal detachment, and cataract. Many subjects demonstrate sensorineural or conductive hearing loss. The inheritance is autosomal dominant with mutations in COL2A1, COL11A1, or COL11A2 or autosomal recessive due to mutations in COL9A1, COL9A2, or COL9A3. We describe a family with Stickler syndrome caused by homozygous loss-of-function mutations in COL9A2. Methods: Two brothers from a consanguineous family were examined with genetic testing, visual acuity, Goldmann perimetry, full-field and multifocal electroretinography (ffERG, mERG), optical coherence tomography (OCT), fundus autofluorescence (FAF), fundus photography, and pure-tone audiograms. Results: Both subjects were homozygous for the mutation c.1332del in COL9A2. Their parents were heterozygous for the same mutation. The boys demonstrated reduced visual acuity, vitreous changes and myopia. The proband was operated for retinal detachment and cataract in one eye. FfERG revealed reduced function of both rods and cones and mERG showed reduced macular function. No morphological macular changes were found by OCT or FAF. Both brothers have severe sensorineural hearing loss with down-sloping audiograms but only subtle midface hypoplasia and no, or mild joint problems. Conclusion: Only a few families with Stickler syndrome caused by COL9A2 mutations have been reported. We confirm previous descriptions with a severe ocular and auditory phenotype but mild orofacial and joint manifestations. Moreover, we demonstrate reduced macular and overall retinal function explaining the reduced visual acuity in patients with Stickler syndrome also without retinal complications.

Molecular genetics with clinical characteristics of Leber congenital amaurosis in the Han population of western China.

Abstract: Purpose: Leber congenital amaurosis (LCA) is one of the earliest inherited retinal dystrophies (IRD) that leads to blindness. To date, there have been 25 LCA-associated genes reported in China as well as other countries. The current study aimed to present the dominant molecular genetics and clinical features of LCA in the Han population of western China.Methods: Our study comprised 37 patients with strictly defined Leber congenital amaurosis in a cohort of IRD (2009-2019). The mutations were detected by targeted next-generation sequencing (NGS), Sanger sequencing, and segregation analysis. The patients underwent comprehensive clinical examinations, analysis of phenotypes and genotypes.Results: Out of the 37 patients, 34 harbored known LCA genes; the detection rate of mutations was 91.9%. Forty-seven different alleles incorporated 21 novel mutations; 8 were known LCA-associated genes. The three most frequently mutated genes included CRB1 (27.0%), RDH12 (24.3%), and RPGRIP1 (18.9%). The CRB1-associated LCA showed a pigmented fundus; the RDH12-associated LCA featured macular atrophy. Our results revealed that CRB1 and RPGRIP1 genes occupied a greater proportion in the western Chinese population. The proportion of these two genes was similar in other regions of China as well. The difference existed in a larger proportion of RDH12-associated LCA in the western Chinese population.Conclusions: The new findings in our study group polished the spectrum of the novel mutations and phenotypes of LCA with regional and ethnic variations. This comprehensive database can provide essential information for gene therapies.

Genotype-phenotype associations in Danish patients with ocular and oculocutaneous albinism.

Abstract: The study aimed to describe genotype-phenotype associations in patients with oculocutaneous and ocular-only albinism and to evaluate a set of diagnostic criteria proposed recently by Kruijt et al.G...

The relationship of retinopathy of prematurity with brain-derivated neurotrophic factor, vascular endotelial growth factor-A, endothelial PAD domain protein 1 and nitric oxide synthase 3 gene polymorphisms.

Abstract: BACKGROUND In addition to risk factors such as low birth weight and uncontrolled oxygen therapy, genetic predisposition is also thought to play a role in the development of retinopathy of prematurity (ROP). In our study, we aimed to analyze single-nucleotide polymorphisms (SNPs) in VEGFA, EPAS1, BDNF and NOS3 genes in infants who develop ROP. MATERIALS AND METHODS Seventy-five mild-moderate and 73 severe ROP cases were included in this study. Eleven different SNPs regions that located in VEGFA, EPAS1, BDNF and NOS3 genes were analysed by SnapShot technique and compared between two groups by the multiple logistic regression analysis. RESULTS Statistically significant results were obtained in 8 of the 11 SNPs. It was observed that the excess of mutant alleles in four (VEGFA rs2010963 and rs3025039, EPAS1 rs13419896, NOS3 rs2070744) of these regions increased ROP severity and treatment requirement (p < .001, p < .001, p = .022, p = .004, respectively) while the excess of mutant alleles in the other four regions (VEGFA rs833061, BDNF rs7929344, EPAS1 rs1867785 and rs1868085) showed that ROP severtiy was milder and eliminated the need for treatment (p < .001, p = .019, p = .017, p = .017, respectively). CONCLUSIONS Considering the results of our study, it was seen that besides the known environmental and demographic factors in ROP pathogenesis, genetic predisposition also had an effect on the clinic and course of ROP. Polymorphisms of VEGFA rs2010963 and rs3025039, EPAS1 rs13419896, NOS3 rs2070744 were found to be associated with severe ROP. More studies involving different populations cases are needed to confirm these findings and enlighten the etiology of ROP.

Expanding the clinical spectrum and management of Traboulsi syndrome: report on two siblings homozygous for a novel pathogenic variant in ASPH.

Abstract: Background Traboulsi syndrome is a very rare, syndromic form of ectopia lentis that is potentially sight-threatening at a young age. It is characterized by typical facial, skeletal and ocular signs. Materials and methods Two siblings, born to consanguineous parents, with a clinical phenotype consistent with Traboulsi syndrome, underwent extensive ophthalmic imaging and exome-based genetic testing. Both were treated with unilateral clear lens extraction via a limbal approach. Results Two siblings, one male and one female, presented with systemic and ocular features consistent with Traboulsi syndrome. Lens subluxation was present in all 4fouraffected eyes, and spontaneous subconjunctival bleb formation was detected in one eye. This eye also showed evidence of keratoconus-related corneal thinning. The clinical diagnosis of Traboulsi syndrome was confirmed molecularly. A homozygous, novel, pathogenic nonsense variant was identified in exon 25 of the ASPH gene: c.2181_2183dup, p.(Val727_Trp728insTer). Excellent visual outcomes following clear lens extraction and postoperative rigid gas-permeable contact lens fitting were obtained. Conclusions We expanded the genetic spectrum of Traboulsi syndrome with a novel frameshift variant in the ASPH gene. We showed that lensectomy followed by gas-permeable contact lenses is an efficient therapeutic approach to treat lens subluxation in Traboulsi syndrome. However, lifelong follow-up is crucial to avoid (late) postoperative complications.

Mitochondrial DNA A3243G variant-associated retinopathy: a meta-analysis of the clinical course of visual acuity and correlation with systemic manifestations.

Abstract: Purpose: The mitochondrial DNA A3243G (m.3243A>G) variant causes a wide spectrum of phenotypes, with pigmentary retinopathy as the most common ocular finding. We undertook this meta-analysis to investigate the clinical course of visual acuity (VA) in patients with m.3243A>G variant and provide key clinical correlations with systemic manifestations.Methods: A PubMed literature search was performed and studies were selected after satisfying pre-set inclusion criteria. Demographic and clinical data, including retinal findings and systemic manifestations were recorded. Cross-sectional and linear regression analyses were used to investigate the relationship between VA and age, as well as between the age at diagnosis of retinopathy and the mean ages at diagnosis of sensorineural hearing loss or diabetes. The age and prevalence of systemic manifestations among patients with and without retinopathy were studied using t-tests and Mann-Whitney U-tests (performed on binarized data). Likelihood ratios were computed.Results: The mean VA (average of both eyes) of 90 patients (72.2% female; 65/90) were collected from 18 studies published between 1990 and 2018. The baseline mean age was 45.2 years (range 17 to 92). The mean logMAR VA was 0.10 (- 0.12 to 1.39). There was a statistically significant linear correlation between the logMAR VA and age (p = .008). The VA of patients less than or equal to 50 years of age was significantly better than that of patients older than 50 years (0.06 vs.0.18 logMAR, p = .002). 67 patients (74.4%) showed a characteristic pigmentary retinopathy with a mean age at diagnosis of 47.9 years (17 to 92) and VA of 0.14 logMAR (- 0.12 to 1.24). Age at diagnosis of retinopathy was linearly correlated with age at diagnosis of hearing loss or diabetes (p G variant pigmentary retinopathy maintain highly functional VA until around the fifth decade of life, after which significant visual decline ensues. Patients without hearing loss and diabetes have a lower likelihood of exhibiting a retinopathy, which tends to appear about one decade after hearing loss and diabetes are diagnosed.

A homozygous POC1B variant causes recessive cone-rod dystrophy

Abstract: Purpose: To report a case of initial cone dystrophy that advanced to a cone-rod dystrophy with homozygous variants in the POC1B gene.Methods: Retinal structure and visual function assessments were ...

Deep clinical phenotyping and gene expression analysis in a patient with RCBTB1-associated retinopathy.

Abstract: Background: Mutations in the RCC1 and BTB domain-containing protein 1 (RCBTB1) gene have been implicated in a rare form of retinal dystrophy. Herein, we report the clinical features of a 45-year-ol...

Identification of a novel nonsense variant in FYCO1 gene associated with infantile cataract and cortical atrophy.

Abstract: Cataract is a major condition characterized by ocular lens opacification, resulting from alteration in the lens architecture, lens proteins or both. It is responsible for about one-third of infants...

CRISPR Cas9 based genome editing in inherited retinal dystrophies.

Abstract: Precision genome engineering, with targeted therapy towards patient-specific mutations is predicted to be the future of personalized medicine. Ophthalmology is in the frontiers of development of ta...

Genetic causes of nystagmus, foveal hypoplasia and subnormal visual acuity- other than albinism.

Abstract: Background: To describe genetic molecular findings in individuals with congenital nystagmus, foveal hypoplasia, and subnormal vision, with normal ocular pigmentation (absence of diffuse transillumination or transparent retinal pigment typical for albinism).Methods: This is a retrospective, multicenter study of ophthalmic, systemic, and genetic features, as collected from medical records of patients diagnosed with infantile nystagmus and foveal hypoplasia. Ophthalmic findings include best-corrected visual acuity (BCVA), biomicroscopic examination, cycloplegic refraction, retinal examination, macular optical coherence tomography, and electroretinography. Genetic information was retrieved from the participating genetic clinics and included ethnicity and molecular diagnosis.Results: Thirty-one individuals met the inclusion criteria and had a secure molecular diagnosis. Mutations in two genes predominated, constituting 77.4% of all the represented genes: SLC38A8 (45.1%) and PAX6 (32.3%). Seventy-eight percent of the subjects who had a measurable BCVA had moderate and severe visual impairment (range 20/80 to 20/270). Most patients with a mutation in SLC38A8 had mild to moderate astigmatism, while most patients with PAX6 mutation had moderate and severe myopia. Patients in the PAX6 group had variable degrees of anterior segment manifestations.Conclusion: In our cohort, the main causative genes for congenital nystagmus and foveal hypoplasia in normally pigmented eyes were SLC38A8 and PAX6. A mild phenotype in PAX6 mutations may be an under-diagnosed cause of nystagmus and foveal hypoplasia. Reaching an accurate genetic diagnosis is essential for both the patients and their family members. This enables predicting disease prognosis, tailoring correct follow-up, and providing genetic counseling and family planning to affected families.