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19 result(s) for "Mora, Jaume Català"
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The landscape of submicroscopic structural variants at the OPN1LW/OPN1MW gene cluster on Xq28 underlying blue cone monochromacy
Blue cone monochromacy (BCM) is an X-linked retinal disorder characterized by low vision, photoaversion, and poor color discrimination. BCM is due to the lack of long-wavelength-sensitive and middle-wavelength-sensitive cone photoreceptor function and caused by mutations in the OPN1LW/OPN1MW gene cluster on Xq28. Here, we investigated the prevalence and the landscape of submicroscopic structural variants (SVs) at single-base resolution in BCM patients. We found that about onethird (n = 73) of the 213 molecularly confirmed BCM families carry an SV, most commonly deletions restricted to the OPN1LW/OPN1MW gene cluster. The structure and precise breakpoints of the SVs were resolved in all but one of the 73 families. Twenty-two families—all from the United States—showed the same SV, and we confirmed a common ancestry of this mutation. In total, 42 distinct SVs were identified, including 40 previously unreported SVs, thereby quadrupling the number of precisely mapped SVs underlying BCM. Notably, there was no “region of overlap” among these SVs. However, 90% of SVs encompass the upstream locus control region, an essential enhancer element. Its minimal functional extent based on deletion mapping in patients was refined to 358 bp. Breakpoint analyses suggest diverse mechanisms underlying SV formation as well as in one case the gene conversionbased exchange of a 142-bp deletion between opsin genes. Using parsimonious assumptions, we reconstructed the composition and copy number of the OPN1LW/OPN1MW gene cluster prior to the mutation event and found evidence that large gene arrays may be predisposed to the occurrence of SVs at this locus.
Angioid streaks and obstructive sleep apnea syndrome: are they related?
BackgroundSleep apnea syndrome (OSAS) has been associated with different ocular manifestations including glaucoma, floppy eye syndrome, punctate keratitis, keratoconus, and optic neuropathy. Angioid streaks are mainly associated with pseudoxanthoma elasticum (PXE) although they can appear in other systemic conditions affecting the elastic fibers.MethodsThis is a prospective, cross-sectional study. A complete ophthalmic examination was performed in 92 patients undergoing overnight polysomnography for suspicion of OSAS. Diagnosis and classification of OSAS were made based on apnea-hypopnea index (AHI). Stereoscopic optic disc photographs were taken in all patients and independently evaluated by two ophthalmologists. Patients with angioid streaks were referred to a dermatologist for axillary skin biopsy in order to rule out pseudoxanthoma elasticum or other skin abnormalities.ResultsBilateral angioid streaks were observed in three patients who had been diagnosed with severe OSAS (AHI > 30/h). No clinical features characteristic of pseudoxanthoma elasticum or other pathological skin signs were observed. Skin biopsies were normal for all three patients, supporting the diagnosis of idiopathic angioid streaks. One of the patients developed bilateral choroidal neovascularization secondary to the angioid streaks over subsequent years.ConclusionsIn view of the low prevalence of idiopathic angioid streaks in the general population, the finding of angioid streaks in patients with severe OSAS suggests OSAS as a possible risk factor for its development. The hypothesis of a connective tissue abnormality that could explain an association between both entities deserves further elucidation.
Retinal findings in pediatric patients with Usher syndrome Type 1 due to mutations in MYO7A gene
PurposeTo describe retinal alterations detected by swept-source optical coherence tomography (SS-OCT) in paediatric patients with Usher syndrome type 1 (USH1) and to compare these findings to previously published reports.MethodsThirty-two eyes from 16 patients (11 males and 5 females) with a genetic diagnosis of USH1 because of MYO7A mutations underwent SS-OCT. Patients ranged in age from 4 to 17 years (mean, 11,13 ± 4,29). The subfoveal and macular area were analysed with SS-OCT at 1050 nm using 12 radial scans of 12.0 mm. Structural abnormalities were evaluated and correlated with best-corrected visual acuity (BCVA).ResultsThe most common qualitative retinal abnormality was external layer damage in macular area. Specific alterations included external limiting membrane loss/disruption (27 eyes; 84.4%), disruption of the Myoid zone (27 eyes; 84.4%); Ellipsoid zone disruption (28 eyes; 87.5%), and loss of the outer segments (29 eyes; 90.6%). The damage of the retinal pigment epithelium was divided according to the loss of the different layers: phagosome zone (30 eyes; 93.8%), melanosome zone (29 eyes; 90.6%) and mitochondria zone (0 eyes; 0%). The presence of cystoid macular oedema (CMO) was significantly correlated with alterations in photoreceptors. Disruption or absence of the myoid and ellipsoid zones of the photoreceptors were the only variables independently associated with decreased BCVA.ConclusionsThe findings of this study suggest that the physiopathologic basis of early-stage Usher syndrome (USH) may be changes in the outer retinal layer, particularly the photoreceptors, which in turn may cause alterations—such as CMO—in the inner retinal layers. Accordingly, monitoring the condition of photoreceptors during follow-up may be advisable for the early detection of pathologic changes.
Expanding the Clinical Spectrum of CEP290 Variants: A Case Report on Non-Syndromic Retinal Dystrophy with a Mild Phenotype
Background/Objectives: Biallelic pathogenic variants in the CEP290 gene are typically associated with severe, early-onset inherited retinal dystrophies (IRDs) in both syndromic and non-syndromic forms. This study explores the phenotypic variability of non-syndromic IRDs associated with CEP290 variants, focusing on two siblings with biallelic variants, one of whom exhibits a remarkably mild phenotype, thereby expanding the clinical spectrum. Methods: Whole-exome sequencing (WES) and mRNA analysis were performed to identify and characterize CEP290 variants in the siblings. Comprehensive ophthalmologic evaluations assessed retinal function and disease progression. Results: Two CEP290 variants, a frameshift (c.955del, p.(Ser319LeufsTer16)) and a missense (c.5777G>C, p.(Arg1926Pro)), were identified in trans in both siblings. Despite sharing the same genetic variants, the sister exhibited significantly preserved retinal function, while the brother presented with a more severe, progressive retinal dystrophy. Conclusions: This study broadens the phenotypic spectrum of non-syndromic CEP290-related IRDs, demonstrating variability in disease severity ranging from mild to severe. These findings highlight the importance of personalized monitoring and tailored management strategies based on individual clinical presentations of CEP290-related IRDs.
DNA Methylomes Reveal Biological Networks Involved in Human Eye Development, Functions and Associated Disorders
This work provides a comprehensive CpG methylation landscape of the different layers of the human eye that unveils the gene networks associated with their biological functions and how these are disrupted in common visual disorders. Herein, we firstly determined the role of CpG methylation in the regulation of ocular tissue-specification and described hypermethylation of retinal transcription factors (i.e., PAX6, RAX, SIX6) in a tissue-dependent manner. Second, we have characterized the DNA methylome of visual disorders linked to internal and external environmental factors. Main conclusions allow certifying that crucial pathways related to Wnt-MAPK signaling pathways or neuroinflammation are epigenetically controlled in the fibrotic disorders involved in retinal detachment, but results also reinforced the contribution of neurovascularization (ETS1, HES5, PRDM16) in diabetic retinopathy. Finally, we had studied the methylome in the most frequent intraocular tumors in adults and children (uveal melanoma and retinoblastoma, respectively). We observed that hypermethylation of tumor suppressor genes is a frequent event in ocular tumors, but also unmethylation is associated with tumorogenesis. Interestingly, unmethylation of the proto-oncogen RAB31 was a predictor of metastasis risk in uveal melanoma. Loss of methylation of the oncogenic mir-17-92 cluster was detected in primary tissues but also in blood from patients.
Optical coherence tomography biomarkers in MYO7A-inherited retinal dystrophy: longitudinal study in pediatric patients
Purpose This study aims to answer a key question: is MYO7A -inherited retinal dystrophy ( MYO7A -IRD) a photoreceptor-first or retinal pigment epithelium-first disease? A second aim was to determine the most useful biomarkers to monitor disease progression in pediatric patients with Usher syndrome type 1B (USH1) secondary to MYO7A mutation. Methods Fifty-two eyes from 26 patients with genetically-confirmed MYO7A -IRD underwent swept-source optical coherence tomography (SS-OCT). Structural abnormalities were evaluated and correlated with follow-up time and best corrected visual acuity (BCVA). All patients were evaluated at baseline and after ≥ 40 months of follow-up. Results The mean (SD) patient age was 9.92 (± 4.1) years. Mean follow-up time was 43 (± 3.2) months. At the final evaluation, the most common qualitative abnormalities in the subfoveal area were alterations in the photoreceptor outer segments (76.9% of eyes) and in the interdigitation zone (IZ) (80.8%). The presence of cystoid macular edema at baseline was independently associated with worse BCVA at the final assessment (increase in LogMAR estimate = 0.142; t(45.00) = 2.78, p  = 0.009). The mean width of the ellipsoid and interdigitation zones decreased significantly (by 668 μm and 278 μm, respectively; both p  < 0.001). Conclusion This study shows that disruption of the photoreceptor outer segments and the IZ are the first alterations detected by SS-OCT in the early phases of MYO7A -IRD. These data highlight the potential value of measuring the width of the ellipsoid and IZ to evaluate disease progression. These findings also demonstrate the utility of monitoring for the emergence of cystic lesions as biomarkers of worse visual prognosis in patients with MYO7A -IRD.
Retinoblastoma seeds: impact on American Joint Committee on Cancer clinical staging
AimTo investigate whether the American Joint Committee on Cancer (AJCC) clinical category cT2b needs to be subclassified by the type and distribution of retinoblastoma (RB) seeding.MethodsMulticentre, international registry-based data were collected from RB centres enrolled between January 2001 and December 2013. 1054 RB eyes with vitreous or subretinal seeds from 18 ophthalmic oncology centres, in 13 countries within six continents were analysed. Local treatment failure was defined as the use of secondary enucleation or external beam radiation therapy (EBRT) and was estimated with the Kaplan-Meier method.ResultsClinical category cT2b included 1054 eyes. Median age at presentation was 16.0 months. Of these, 428 (40.6%) eyes were salvaged, and 430 (40.8%) were treated with primary and 196 (18.6%) with secondary enucleation. Of the 592 eyes that had complete data for globe salvage analysis, the distribution of seeds was focal in 143 (24.2%) and diffuse in 449 (75.8%). The 5-year Kaplan-Meier cumulative globe-salvage (without EBRT) was 78% and 49% for eyes with focal and diffuse RB seeding, respectively. Cox proportional hazards regression analysis confirmed a higher local treatment failure risk with diffuse seeds as compared with focal seeds (hazard rate: 2.8; p<0.001). There was insufficient evidence to prove or disprove an association between vitreous seed type and local treatment failure risk(p=0.06).ConclusionThis international, multicentre, registry-based analysis of RB eyes affirmed that eyes with diffuse intraocular distribution of RB seeds at diagnosis had a higher risk of local treatment failure when compared with focal seeds. Subclassification of AJCC RB category cT2b into focal vs diffuse seeds will improve prognostication for eye salvage.
Macular Hole After Poppers (Alkyl Nitrate) Inhalation in a Child
The authors present the first case of macular hole (MH) after a single inhalation of poppers. A 13-year-old girl presented with vision loss in the left eye (OS). Pediatric and neurology exams were normal. Funduscopy revealed bilateral papilledema and yellow foveal spot OS. Optic neuritis was diagnosed and treated. Due to foveal alteration, optical coherence tomography was performed, and MH was diagnosed. Twenty-three-gauge pars plana vitrectomy, peeling of the internal limiting membrane, and SF 6 exchange were performed. Postoperatively, vision restoration and MH closure were observed. Although MH mechanism in the poppers context is unknown, the classic surgery is effective. [ Ophthalmic Surg Lasers Imaging Retina. 2018;49:897–900.]
Increasing the Genetic Diagnosis Yield in Inherited Retinal Dystrophies: Assigning Pathogenicity to Novel Non-canonical Splice Site Variants
Aims: We aimed to validate the pathogenicity of genetic variants identified in inherited retinal dystrophy (IRD) patients, which were located in non-canonical splice sites (NCSS). Methods: After next generation sequencing (NGS) analysis (target gene panels or whole exome sequencing (WES)), NCSS variants were prioritized according to in silico predictions. In vivo and in vitro functional tests were used to validate their pathogenicity. Results: Four novel NCSS variants have been identified. They are located in intron 33 and 34 of ABCA4 (c.4774-9G>A and c.4849-8C>G, respectively), intron 2 of POC1B (c.101-3T>G) and intron 3 of RP2 (c.884-14G>A). Functional analysis detected different aberrant splicing events, including intron retention, exon skipping and intronic nucleotide addition, whose molecular effect was either the disruption or the elongation of the open reading frame of the corresponding gene. Conclusions: Our data increase the genetic diagnostic yield of IRD patients and expand the landscape of pathogenic variants, which will have an impact on the genotype–phenotype correlations and allow patients to opt for the emerging gene and cell therapies.
Follow‐up of intraocular retinoblastoma through the quantitative analysis of conserved nuclear DNA sequences in aqueous humor from patients
Fundoscopy is the standard method for diagnosis and follow‐up of intraocular retinoblastoma, but it is sometimes insufficient to discern whether tumors are inactivated following treatments. In this work, we hypothesized that the amount of conserved nuclear DNA sequences in the cell‐free DNA (cfDNA) fraction of the aqueous humor (AH) might complement fundoscopy for retinoblastoma follow‐up. To address our hypothesis, we developed highly sensitive droplet digital polymerase chain reaction (ddPCR) methods to quantify highly conserved DNA sequences of nucleus‐encoded genes (GAPDH and B4GALNT1) and of a mitochondrial gene, MT‐ATP6. We obtained AH samples during intravitreal treatments. We analyzed 42 AH samples from 25 patients with intraocular retinoblastoma and 11 AH from controls (non‐cancer patients). According to clinical criteria, we grouped patients as having progression‐free or progressive retinoblastoma. cfDNA concentration in the AH was similar in both retinoblastoma groups. Copy counts for nucleus‐derived sequences of GAPDH and B4GALNT1 were significantly higher in the AH from patients with progressive disease, compared to the AH from progression‐free patients and control non‐cancer patients. The presence of mitochondrial DNA in the AH explained that both retinoblastoma groups had similar cfDNA concentration in AH. The optimal cut‐off point for discriminating between progressive and progression‐free retinoblastomas was 108 GAPDH copies per reaction. Among patients having serial AH samples analyzed during their intravitreal chemotherapy, GAPDH copies were high and decreased below the cut‐off point in those patients responding to chemotherapy. In contrast, one non‐responder patient remained with values above the cut‐off during follow‐up, until enucleation. We conclude that the measurement of conserved nuclear gene sequences in AH allows follow‐up of intraocular retinoblastoma during intravitreal treatment. The method is applicable to all patients and could be relevant for those in which fundoscopy evaluation is inconclusive.