Leber Congenital Amaurosis Associated with Mutations in CEP290, Clinical Phenotype, and Natural History in Preparation for Trials of Novel Therapies.

PURPOSE: To investigate and describe in detail the demographics, functional and anatomic characteristics, and clinical course of Leber congenital amaurosis (LCA) associated with mutations in the CEP290 gene (LCA-CEP290) in a large cohort of adults and children. DESIGN: Retrospective case series. PARTICIPANTS: Patients with mutations in CEP290 identified at a single UK referral center. METHODS: Review of case notes and results of retinal imaging (color fundus photography, fundus autofluorescence [FAF] imaging, OCT), electrophysiologic assessment, and molecular genetic testing. MAIN OUTCOME MEASURES: Molecular genetic testing, clinical findings including visual acuity and retinal imaging, and electrophysiologic assessment. RESULTS: Forty patients with LCA-CEP290 were identified. The deep intronic mutation c.2991+1655 A>G was the most common disease-causing variant (23/40 patients) identified in the compound heterozygous state in 20 patients (50%) and homozygous in 2 patients (5%). Visual acuity (VA) varied from 6/9 to no perception of light, and only 2 of 12 patients with longitudinal VA data showed deterioration in VA in their better-seeing eye over time. A normal fundus was found at diagnosis in younger patients (mean age, 1.9 years), with older patients showing white flecks (mean age, 5.9 years) or pigmentary retinopathy (mean age, 21.7 years). Eleven of 12 patients (92%) with OCT imaging had preservation of foveal architecture. Ten of 12 patients (83%) with FAF imaging had a perifoveal hyperautofluorescent ring. Having 2 nonsense CEP290 mutations was associated with worse final VA and the presence of nonocular features. CONCLUSIONS: Detailed analysis of the clinical phenotype of LCA-CEP290 in a large cohort confirms that there is a window of opportunity in childhood for therapeutic intervention based on relative structural preservation in the central cone-rich retina in a significant proportion of patients, with the majority harboring the deep intronic variant potentially tractable to several planned gene editing approaches.

Early onset retinal dystrophy due to mutations in LRAT: molecular analysis and detailed phenotypic study.

PURPOSE: To report novel variants and characterize the phenotype associated with the autosomal recessive retinal dystrophy caused by mutations in the lecithin retinol acyltransferase (LRAT) gene. METHODS: A total of 149 patients with Leber's congenital amaurosis (LCA) or early onset retinal dystrophy were screened for mutations in LCA-associated genes using an arrayed-primer extension (APEX) genotyping microarray (Asper Ophthalmics). LRAT sequencing was subsequently performed in this 148-patient panel. Patients identified with mutations underwent further detailed phenotyping. RESULTS: APEX analysis identified one patient with a previously reported homozygous LRAT mutation. Sequencing of the panel identified three additional patients with novel homozygous LRAT mutations in exon 2. All four patients had severe progressive nyctalopia, visual field constriction, and photophilia in childhood. Visual acuity ranged from 0.22 logMAR to hand motion. Funduscopy revealed severe retinal pigment epithelial atrophy and minimal retinal pigmentation. Asteroid hyalosis and macular epiretinal fibrosis were frequent. All demonstrated reduced fundus autofluorescence. Optical coherence tomography identified disrupted retinal lamination, outer-retinal debris, and an unidentifiable photoreceptor layer in two cases. Full-field electroretinograms were undetectable or showed severe rod-cone dysfunction. Photopic perimetry revealed severe visual field constriction. Dark-adapted perimetry demonstrated markedly reduced photoreceptor sensitivity. Dark-adapted spectral sensitivity measurements identified functioning rods in two of three patients. All three had severely reduced L- and M-cone sensitivity and poor color discrimination. CONCLUSIONS: LRAT mutations cause a severe, early childhood onset, progressive retinal dystrophy. Phenotypic similarities to the retinal dysfunction associated with RPE-specific protein 65 kDa mutations, another visual cycle gene, suggest that LRAT deficiency may show a good response to novel therapies.

Leber congenital amaurosis associated with AIPL1: challenges in ascribing disease causation, clinical findings, and implications for gene therapy.

Leber Congenital Amaurosis (LCA) and Early Childhood Onset Severe Retinal Dystrophy are clinically and genetically heterogeneous retinal disorders characterised by visual impairment and nystagmus from birth or early infancy. We investigated the prevalence of sequence variants in AIPL1 in a large cohort of such patients (n = 392) and probed the likelihood of disease-causation of the identified variants, subsequently undertaking a detailed assessment of the phenotype of patients with disease-causing mutations. Genomic DNA samples were screened for known variants in the AIPL1 gene using a microarray LCA chip, with 153 of these cases then being directly sequenced. The assessment of disease-causation of identified AIPL1 variants included segregation testing, assessing evolutionary conservation and in silico predictions of pathogenicity. The chip identified AIPL1 variants in 12 patients. Sequencing of AIPL1 in 153 patients and 96 controls found a total of 46 variants, with 29 being novel. In silico analysis suggested that only 6 of these variants are likely to be disease-causing, indicating a previously unrecognized high degree of polymorphism. Seven patients were identified with biallelic changes in AIPL1 likely to be disease-causing. In the youngest subject, electroretinography revealed reduced cone photoreceptor function, but rod responses were within normal limits, with no measurable ERG in other patients. An increasing degree and extent of peripheral retinal pigmentation and degree of maculopathy was noted with increasing age in our series. AIPL1 is significantly polymorphic in both controls and patients, thereby complicating the establishment of disease-causation of identified variants. Despite the associated phenotype being characterised by early-onset severe visual loss in our patient series, there was some evidence of a degree of retinal structural and functional preservation, which was most marked in the youngest patient in our cohort. This data suggests that there are patients who have a reasonable window of opportunity for gene therapy in childhood.

RDH12 retinopathy: novel mutations and phenotypic description.

PURPOSE: To identify patients with autosomal recessive retinal dystrophy caused by mutations in the gene, retinal dehydrogenase 12 (RDH12), and to report the associated phenotype. METHODS: After giving informed consent, all patients underwent full clinical evaluation. Patients were selected for mutation analysis based upon positive results from the Asper Ophthalmics Leber congenital amaurosis arrayed primer extansion (APEX) microarray screening, linkage analysis, or their clinical phenotype. All coding exons of RDH12 were screened by direct Sanger sequencing. Potential variants were checked for segregation in the respective families and screened in controls, and their pathogenicity analyzed using in silico prediction programs. RESULTS: Screening of 389 probands by the APEX microarray and/or direct sequencing identified bi-allelic mutations in 29 families. Seventeen novel mutations were identified. The phenotype in these patients presented with a severe early-onset rod-cone dystrophy. Funduscopy showed severe generalized retinal pigment epithelial and retinal atrophy, which progressed to dense, widespread intraretinal pigment migration by adulthood. The macula showed severe atrophy, with pigmentation and yellowing, and corresponding loss of fundus autofluorescence. Optical coherence tomography revealed marked retinal thinning and excavation at the macula. CONCLUSIONS: RDH12 mutations account for approximately 7% of disease in our cohort of patients diagnosed with Leber congenital amaurosis and early-onset retinal dystrophy. The clinical features of this disorder are highly characteristic and facilitate candidate gene screening. The term RDH12 retinopathy is proposed as a more accurate description.

Epibulbar molluscum contagiosum lesions in multiple myeloma.

PURPOSE: To describe the history and clinical presentation of a case of primary epibulbar molluscum contagiosum in multiple myeloma, after penetrating keratoplasty. METHODS: A 70-year-old man, with previously diagnosed multiple myeloma and atopic dermatitis and keratoconjunctivitis, presented 6 months after right penetrating keratoplasty with white multilobular nodules of the right limbus. No skin lesions were evident. Evaluation consisted of slit-lamp examination, and an excisional biopsy of the involved conjunctival epithelium was carried out with local cryotherapy. Excised tissue was sent for histopathologic studies. RESULTS: Slit-lamp examination revealed the presence of eight, 1-3 mm nodules of the perilimbal conjunctiva. In addition, there were opaque plaques at the level of the corneal epithelium. Mild perilesional conjunctival injection was evident, but there was no follicular conjunctival reaction. Histopathologic study of the lesions revealed eosinophilic intracytoplasmic inclusions (molluscum bodies) within the epithelial tissue. CONCLUSIONS: There are no other reports of primary epibulbar molluscum, without previous cutaneous lesions, in immunocompromised patients without AIDS or after keratoplasty. This diagnosis should be included in the differential of focal thickening of the conjunctival epithelium, and potentially the corneal epithelium, in immunosuppressed patients.

Screening of SPATA7 in patients with Leber congenital amaurosis and severe childhood-onset retinal dystrophy reveals disease-causing mutations.

PURPOSE: To investigate the prevalence of sequence variants in the gene SPATA7 in patients with Leber congenital amaurosis (LCA) and autosomal recessive, severe, early-onset retinal dystrophy (EORD) and to delineate the ocular phenotype associated with SPATA7 mutations. METHODS: Patients underwent standard ophthalmic evaluation after providing informed consent. One hundred forty-one DNA samples from patients with LCA and EORD had been analyzed for mutations by using a microarray, with negative results. One additional patient underwent SPATA7 screening due to a region of autozygosity surrounding this gene. A further patient was screened who had a compatible ocular phenotype. The entire SPATA7 coding sequence was assayed, including the intron-exon junctions, by using a combination of direct DNA sequencing and high-resolution melting screening. RESULTS: Screening of SPATA7 identified several known and novel single-nucleotide polymorphisms (SNPs). Affected individuals from five unrelated families were identified to have coding changes. Clinical features demonstrated a severe infantile onset retinal dystrophy, similar to Leber congenital amaurosis. The retina had widespread retinal pigment epithelial atrophy, with minimal pigment migration into the neurosensory retina. Fundus autofluorescence imaging showed a parafoveal annulus of increased autofluorescence. High-definition optical coherence tomography showed preservation of the inner segment/outer segment junction at the fovea. CONCLUSIONS: Mutations in SPATA7 are a rare cause of childhood retinal dystrophy accounting for 1.7% of disease in this cohort. Affected patients present in infancy with severe visual loss, but may have some preservation of the photoreceptor structure in the central retina.

Phenotypic variability in patients with retinal dystrophies due to mutations in CRB1.

OBJECTIVES: To identify CRB1 mutations in a large cohort of patients with recessive retinal dystrophies and to document the retinal phenotype and visual prognosis. DESIGN: A hospital-based cross-sectional study of children and adults with recessive retinal dystrophies. PARTICIPANTS: Three hundred and six patients with Leber congenital amaurosis (LCA), early-onset childhood retinal dystrophy or juvenile onset retinitis pigmentosa were recruited to the study and gave blood samples for molecular genetic analysis. METHODS: A detailed clinical examination was performed, including: logMAR visual acuity, refraction, Goldmann visual fields, slit-lamp biomicroscopy, fundus photography, autofluorescence imaging and optical coherence tomography. The results of electrophysiology testing were available in all patients. DNA was obtained for molecular genetic analysis. Initial screening for mutations was performed using the LCA chip. Patients who had one or more CRB1 mutations identified on the chip, and other patients whose phenotype suggested a CRB1 genotype, underwent direct sequencing. In addition, consanguineous families segregating recessive RP underwent a whole genome scan using Affymetrix gene chips, and affected family members showing linkage to the RP12 locus underwent sequencing of the CRB1 gene. MAIN OUTCOME MEASURES: Identification of patients with mutations in CRB1 and detailed documentation of the clinical phenotype. RESULTS: Mutations in CRB1, including 17 novel mutations, were identified in 41 patients from 32 families. The authors identified both disease mutations in 34 patients from 26 families, and these patients underwent detailed phenotyping. Common phenotypic features included hypermetropic refractive error, nummular pigmentation at the level of the RPE and increased retinal thickness on optical coherence tomography. Most patients had a clinical and electrophysiological phenotype consistent with a diagnosis of LCA or rod-cone dystrophy, but three patients had electroretinogram evidence of cone-rod degeneration. A minority of patients developed peripheral retinal telangiectasia, which in some cases led to seclusio pupillae and angle-closure glaucoma. CONCLUSION: Mutations in CRB1 are associated with a range of recessively inherited retinal dystrophies, including LCA, childhood- and juvenile-onset rod-cone and cone-rod dystrophies. Although the phenotype is usually severe, in milder cases there is a window of opportunity for therapeutic intervention in early childhood.

Novel mutations in MERTK associated with childhood onset rod-cone dystrophy.

PURPOSE: To report the clinical phenotype in patients with a retinal dystrophy associated with novel mutations in the MER tyrosine kinase (MERTK) gene. METHODS: A consanguineous family of Middle Eastern origin was identified, and affected members underwent a full clinical evaluation. Linkage analysis was performed using the Affymetrix 50K chip. Regions of homozygosity were identified. The positional candidate genes protocadherin 21 (PCDH21), retinal G protein-coupled receptor (RGR), and MERTK were polymerase chain reaction (PCR) amplified and sequenced. Long-range PCR was performed to characterize the deletion. Two hundred and ninety-two probands with autosomal recessive, childhood onset, retinal dystrophies were analyzed using the Asper Ophthalmics Leber congenital amaurosis chip to screen for known MERTK mutations. RESULTS: Analysis of a 50K-Affymetrix whole genome scan identified three regions of homozygosity on chromosomes 2 and 10. Screening of the candidate gene MERTK showed a possible deletion of exon 8. Long-range PCR identified a ~9 kb deletion within MERTK that removes exon 8. Screening of DNA from a panel of Saudi Arabian patients with autosomal recessive retinitis pigmentosa identified a second consanguineous family with the same mutation. One patient with a known MERTK mutation (p.R651X) was identified using the Asper Ophthalmics Leber congenital amaurosis chip. Further screening of the gene identified a second novel splice site mutation in intron 1. The phenotype associated with these identified MERTK mutations is of a childhood onset rod-cone dystrophy with early macular atrophy. The optical coherence tomography (OCT) appearance is distinctive with evidence of debris beneath the sensory retina. CONCLUSIONS: Mutations in MERTK are a rare cause of retinal dystrophy. Non homologous recombination between Alu Y repeats near or within disease genes may be an important cause of retinal dystrophies.

Electrophysiological monitoring in a patient with an optic nerve glioma.

PURPOSE: To report a case illustrating the value of pattern VEP and pattern ERG (PERG) in monitoring optic nerve gliomata (OG). CASE REPORT: A 15-year-old girl presented with a 3-year history of frontal headaches and a 5-month history of blurred vision in the right eye. MRI scanning revealed a thickened, right optic nerve extending to the cranial opening of the optic canal, consistent with an optic nerve glioma. Pattern VEP showed a mildly delayed major positive component consistent with optic nerve dysfunction. The PERG N95:P50 ratio was subnormal in keeping with retinal ganglion cell involvement. Visual acuity decreased over the following 2 years and repeat VEP objectively demonstrated marked deterioration in optic nerve function despite neuroradiology showing no significant change in the tumour. CONCLUSIONS: Pattern VEPs and pattern ERGs can provide early objective evidence of optic nerve/retinal ganglion cell dysfunction in optic nerve gliomata. Serial recordings can objectively demonstrate worsening function in the absence of significant neuroradiological change.

Teenagers' perceptions of blindness related to smoking: a novel message to a vulnerable group.

BACKGROUND: Cigarette smoking often starts in teenage years. It is not known whether teenagers are aware of the association of smoking with eye disease and blindness. AIM: To explore the knowledge of the link between smoking, and eye diseases and blindness, and the likely impact of this knowledge among teenagers in UK. METHODS: A cross-sectional survey, using a structured interview of teenagers attending four organised social events, was conducted. Awareness and fear of blindness, and of three smoking-related diseases (lung cancer, heart disease and stroke) and a distractor condition (deafness) was investigated. The likelihood of smokers quitting on developing early signs of each condition was determined. RESULTS: A 92% "opt in" response rate was achieved. Out of 260 teenagers (16-18 years), 15%, 27% and 81% believed that smoking caused stroke, heart disease and lung cancer, respectively. Only 5% believed smoking caused blindness. Subjects ranked their fear of each of the five conditions, scoring five for the most feared and one for the least feared. Subjects were significantly (p<0.01) more fearful (mean scores in brackets) of blindness (4.2) than of lung cancer (3.4), heart disease (2.3) and deafness (1.2). More teenagers (p<0.01) said they would stop smoking on developing early signs of blindness compared with early signs of lung or heart disease. CONCLUSIONS: Awareness of the risk of blindness from smoking is low among teenagers, but fear of blindness may be more likely to motivate teenagers to stop smoking than fear of lung or heart disease. Teenagers should be made more aware of the ocular risks of cigarette smoking as a novel public health measure.