Search Results (196)

The aim of this paper is to present our experience with the diagnosis and management of nine patients diagnosed with Leber’s hereditay optic neuropathy. Materials and methods: We conducted a prospective, observational study that included nine patients treated with idebenone, followed for a period of 18 months. Results: Our findings suggest that the impact of treatment varies significantly depending on the disease phase. In the acute phase, visual acuity deteriorated from 0.67 logMAR at onset to 0.97 logMAR at 3 months, followed by a slight improvement to 0.88 logMAR at 9 months. In the chronic phase, average values decreased progressively from 1.44 logMAR at onset to 1.26 logMAR at 12 and 18 months. We also observed a consistent treatment benefit over time in eyes harbouring the m.11778 G > A mutation. Although the most powerful predictor of visual outcome remains the mtDNA genotype, young age at onset is correlated with a better prognosis. In the acute phase, more cases of a clinically relevant benefit were observed than expected (33.33% versus 22.22% expected), and fewer clinically relevant worsening cases were observed (0% versus 11.11% expected). Regarding OCT measurement, our study highlighted a significant difference in peripapillary retinal nerve fiber layer thickness between the initial evaluation and the 6-month follow-up (100.83 µm ± 30.2 at baseline versus 96.7 µm ± 24.8 at 6 months). Conclusions: Our paper demonstrates the benefit of idebenone treatment in improving visual acuity in patients with Leber hereditary optic neuropathy. We highlighted the importance of long-term treatment, emphasizing that extended administration is key to achieving favorable outcomes. Full article

Background/Objectives: Senior-Loken syndrome (SLS) is a rare autosomal recessive renal–retinal disease caused by mutations in 10 genes. This study aimed to review the ophthalmic findings, renal function, and genotypes of Korean SLS cases. Methods: We retrospectively reviewed 17 genetically confirmed SLS patients in Korea, including 9 newly identified cases and 8 previously reported. Comprehensive ophthalmologic evaluations and renal assessments were conducted. Genetic testing was performed using whole-genome sequencing (WGS), whole-exome sequencing (WES), or Sanger sequencing. Results: Among the 17 patients, patients with NPHP1 mutations were most common (35.3%), followed by those with NPHP4 (29.4%), IQCB1 (NPHP5, 29.4%), and SDCCAG8 (NPHP10, 5.9%) mutations. Patients with NPHP1 mutations showed retinitis pigmentosa (RP) sine pigmento and preserved central vision independent of renal deterioration. Patients with NPHP4 mutations showed early renal dysfunction. Two patients aged under 20 maintained relatively good visual function, but older individuals progressed to severe retinopathy. Patients with IQCB1 mutations were generally prone to early and severe retinal degeneration, typically manifesting as Leber congenital amaurosis (LCA) (three patients), while two patients exhibited milder RP sine pigmento with preserved central vision. Notably, two out of five (40.0%) maintained normal renal function at the time of diagnosis, and both had large deletions in IQCB1. The patient with SDCCAG8 mutation exhibited both end-stage renal disease and congenital blindness due to LCA. Wide-field fundus autofluorescence (AF) revealed perifoveal and peripapillary hypoAF with a perifoveal hyperAF in younger patients across genotypes. Patients under 20 years old showed relatively preserved central vision, regardless of the underlying genetic mutation. Conclusions: The clinical manifestation of renal and ocular impairment demonstrated heterogeneity among Korean SLS patients according to causative genes, and the severity of renal dysfunction and visual decline was not correlated. Therefore, simultaneous comprehensive evaluations of both renal and ocular function should be performed at the initial diagnosis to guide timely intervention and optimize long-term outcomes. Full article

Pupil cycle time (PCT) estimates the dynamics of a biofeedback loop established between pupil size and stimulus luminance, size or colour. The PCT is useful for probing the functional integrity of the retinopupillary circuits, and is therefore potentially applicable for assessing the effects of damage due to retinopathies or neuropathies. In previous studies, PCT was measured by manually counting the number of pupil oscillations during a fixed period to calculate the PCT. This method is scarce, requires a good expertise and cannot be used to estimate several PCT parameters, such as the oscillation amplitude or variability. We have developed a computerised setup based on eye-tracking that expands the possibilities of characterising PCT along several dimensions: oscillation frequency and regularity, amplitude and variability, which can be used with a large palette of stimuli (different colours, sizes, shapes or locations), and further allows measuring blinking frequency and eye movements. We used this method to characterise the PCT in young control participants as well as in patients with several pathologies, including age-related macular degeneration (AMD), diabetic retinopathy (DR), retinitis pigmentosa (RP), Stargardt disease (SD), and Leber hereditary optic neuropathy (LHON). We found that PCT is very regular and stable in young healthy participants, with little inter-individual variability. In contrast, several PCT features are altered in older healthy participants as well as in ocular diseases, including slower dynamics, irregular oscillations, and reduced oscillation amplitude. The distinction between patients and healthy participants based on the calculation of the area under the curve of the receiver operating characteristics (AUC of ROC) were dependent on the pathologies and stimuli (0.7 < AUC < 1). PCT nevertheless provides relevant complementary information to assess the physiopathology of ocular diseases and to probe the functioning of retino-pupillary circuits. Full article

Background: Syndromic inherited retinal diseases (IRDs) are a clinically and genetically heterogeneous group of disorders, involving the retina and additional organs. Over 80 forms of syndromic IRD have been described. Methods: We aimed to phenotypically and genotypically characterize a cohort of 171 individuals from 140 Israeli families with syndromic IRD. Ophthalmic examination included best corrected visual acuity, fundus examination, visual field testing, retinal imaging and electrophysiological evaluation. Most participants were also evaluated by specialists in fields relevant to their extra-retinal symptoms. Genetic analyses included haplotype analysis, homozygosity mapping, Sanger sequencing and next-generation sequencing. Results: In total, 51% of the families in the cohort were consanguineous. The largest ethnic group was Muslim Arabs. The most common phenotype was Usher syndrome (USH). The most common causative gene was USH2A. In 29% of the families, genetic analysis led to a revised or modified clinical diagnosis. This included confirmation of an atypical USH diagnosis for individuals with late-onset retinitis pigmentosa (RP) and/or hearing loss (HL); diagnosis of Heimler syndrome in individuals with biallelic pathogenic variants in PEX6 and an original diagnosis of USH or nonsyndromic RP; and diagnosis of a mild form of Leber congenital amaurosis with early-onset deafness (LCAEOD) in an individual with a heterozygous pathogenic variant in TUBB4B and an original diagnosis of USH. Novel genotype–phenotype correlations included biallelic pathogenic variants in KATNIP, previously associated with Joubert syndrome (JBTS), in an individual who presented with kidney disease and IRD, but no other features of JBTS. Conclusions: Syndromic IRDs are a highly heterogeneous group of disorders. The rarity of some of these syndromes on one hand, and the co-occurrence of several syndromic and nonsyndromic conditions in some individuals, on the other hand, complicates the diagnostic process. Genetic analysis is the ultimate way to obtain an accurate clinical diagnosis in these individuals. Full article

Background/Objectives: Inherited retinal diseases (IRDs) are a heterogeneous group of rare eye disorders characterized by progressive photoreceptor degeneration, leading to severe visual impairment or even blindness. This study aims to investigate the prevalence, types, and clinical significance of ophthalmic comorbidities in Portuguese patients with IRDs. Methods: This nationwide Portuguese population-based retrospective study was based on the IRD-PT registry (retina.com.pt). Statistical analysis was conducted using Microsoft^® Excel^® for Microsoft 365 and IBM SPSS Statistics version 29.0.2.0. Informed consent was obtained from all participants. Results: A total of 1531 patients (1254 families) from six centers were enrolled. The cohort consisted of 51% males, with a mean age of 45.8 ± 19.3 years and a mean age at diagnosis of 39.4 ± 19.5 years. Overall, ocular comorbidities were reported in 644 patients (42.1%). In 176 individuals (11.5%), multiple concurrent comorbidities were found. Cataract was the most common comorbidity (21.3%), followed by amblyopia (6.3%) and high myopia (5.9%). Statistically significant associations with ocular comorbidities were observed in isolated progressive IRDs. Specifically, AR RP was associated with cataract (p < 0.001), and gene analysis revealed several significant associations. CRB1 was statistically linked to epiretinal membrane (ERM) (p = 0.003), EYS with cataract (p = 0.001), PROM1 with choroidal neovascularization (CNV) (p = 0.0026), and USH2A with macular hole (p = 0.01). Patients with the RPE65 mutation in Leber congenital amaurosis were associated with ERM (p = 0.019). There was also a significant association between X-linked RP and high myopia (p < 0.001) and CNV in Best disease (p < 0.001); in syndromic IRDs, cataract, cystoid macular edema, and ERM were observed in Usher syndrome, p = 0.002, p = 0.002, and p = 0.005, respectively, and the MYO7A gene was linked to cataract (p = 0.041) and strabismus (p = 0.013); pseudoxanthoma elasticum was significantly associated with CNV (p = 0.002); and foveal hypoplasia was associated with anterior segment dysgenesis (p < 0.001). Conclusions: This study enhances the current understanding of ocular comorbidities in IRDs in Portuguese patients. Common findings were cataract, refractive error, and CME. Stationary IRDs and pattern dystrophies showed fewer concomitant comorbidities, supporting their classification as non-progressive or benign conditions. The significance of registries like IRD-PT cannot be overstated, particularly in the context of rare diseases. These databases serve multiple crucial functions in enabling detailed documentation of disease characteristics and long-term monitoring of disease progression. Full article

Allogeneic hematopoietic cell transplantation (alloHCT) is the sole curative therapy for myelodysplastic syndrome (MDS). While alloHCT clearly confers a significant survival advantage in high-risk MDS, it is less clear how the disease burden and impact of conditioning intensity impact survival. This review addresses critical issues surrounding this topic, emphasizing the unique cell biology of MDS and the evolving concepts of conditioning intensity compared to other diseases, including acute myeloid leukemia (AML). The review is structured around three interconnected themes. First, it clarifies the varying interpretations of conditioning intensity. Second, it examines the interplay between disease burden at transplant and conditioning intensity in determining outcomes, including a comparative analysis with acute myeloid leukemia (AML) to highlight similarities and differences. Third, it explores the relationship between conditioning regimen intensity and immune reconstitution, particularly focusing on the graft-versus-tumor (GvT) effect and its potential modulation by conditioning intensity. Understanding the stem cell target of conditioning regimens is emphasized, as the persistence of the underlying MDS stem cell necessitates a thorough understanding of this concept for improved therapeutic strategies. Full article

Precision oncology is becoming a mainstay in the standard of care for cancer patients. Recent technological advancements have significantly lowered the cost of various tumor profiling approaches, broadening the reach of molecular diagnostics and improving patient access to precision oncology. In parallel, drug development and discovery pipelines continue to evolve, driving targeted therapeutic options forward. Yet, not all patients harboring actionable molecular alterations respond to these interventions, and existing therapies do not cover the entire spectrum of potential molecular targets. In this review, we examine the current suite of omics technologies employed in clinical settings and underscore their roles in deepening our understanding of tumor biology and optimizing patient stratification for targeted treatments. We also highlight relevant precision oncology trials and share our own experiences using multi-omics data within a molecular tumor board framework. Finally, we discuss areas for future exploration aimed at propelling precision oncology to new heights. Full article

The m.13513G>A (p.Asp393Asn) substitution in the MT-ND5 (Mitochondrially Encoded NADH/Ubiquinone Oxidoreductase Core Subunit 5) gene is a common pathogenic variant associated with primary mitochondrial disorders. It frequently causes Leigh syndrome and mitochondrial encephalomyopathy with lactate acidosis and stroke-like episodes (MELAS). In this study, we present clinical data, heteroplasmy levels in various tissues (blood, urine, and skin fibroblasts), and bioenergetic characteristics from a cohort of 20 unrelated patients carrying the m.13513G>A mutation, classified according to the following phenotypes: Leigh syndrome (n = 12), MELAS (n = 2), and Leber’s hereditary optic neuropathy (LHON, n = 6). We observed a significant correlation between high respiratory ratios and heteroplasmy levels in fibroblast cell lines of the patients. Furthermore, fibroblast cell lines with heteroplasmy levels exceeding 55% exhibited markedly reduced mitochondrial membrane potential. These findings contribute to a better understanding of the clinical and bioenergetic profiles of patients with m.13513G>A-variant-related phenotypes across different heteroplasmy levels, based on data from a single genetic center. Our data suggest that even a slight shift in heteroplasmy can improve cellular function and, consequently, the patients’ phenotype, providing a solid foundation for the development of future gene therapies for mtDNA diseases. Full article

Nonsyndromic and syndromic hereditary optic neuropathies (HONs) encompass a variety of genetic illnesses that cause progressive optic nerve damage, resulting in considerable vision impairment. These disorders result from pathogenic variants in mitochondrial or nuclear DNA, impacting essential cellular processes like oxidative phosphorylation, mitochondrial dynamics, and neuroprotection. Advances in next-generation sequencing (NGS) have significantly improved the identification of genetic variations, enabling precise diagnoses and genotype–phenotype correlations. This review consolidates current knowledge regarding the classification, molecular pathogenesis, clinical manifestations, diagnostic methodologies, and emerging therapeutic strategies for HONs. The critical role of mitochondrial dysfunction in optic nerve degeneration highlights the necessity for multimodal therapeutic approaches. Recent clinical trials evaluating gene therapy for Leber hereditary optic neuropathy (LHON) and neuroprotective strategies in dominant optic atrophy (DOA) are discussed. Additionally, individualized therapeutic interventions, as demonstrated by recent case studies involving tailored gene therapies, are evaluated. The integration of molecular and imaging biomarkers in future personalized treatment strategies aims to enhance prognosis and therapeutic outcomes. Full article

Host microbiota may impact disease vector behavior and pathogen transmission, but little is known about associations between ectoparasites and microbial communities in wildlife reservoir species. We used Illumina metagenomic sequencing to explore the impacts of tick parasitism on the rodent fecal microbiome in both a field and laboratory setting. We found that tick parasitism on wild hosts was associated with variation in the fecal microbiota of both the white-footed deermouse, Peromyscus leucopus, and the southern cotton rat, Sigmodon hispidus. In a lab experiment, we detected significant changes to the fecal microbiome after experimental exposure to immature ticks in treated versus control BALB/c mice. Whereas there is variation in the fecal microbiome associated with each of the host species we tested, some of the same microbial taxa, notably members of the family Muribaculaceae, occurred at higher relative abundance in tick-parasitized hosts in both the field and laboratory studies, suggesting that there are consistent impacts of tick parasitism on the host gut microbiome. We recommend future studies to test the hypothesis that epithelial cell secretions, generated as part of the host’s immune response to tick parasitism, could provide resources that allow particular microbial lineages in the mammalian gut to flourish. Full article

Disease-causing variants in the IDH3A gene are associated with autosomal recessive retinitis pigmentosa 90 (RP90) and Leber congenital amaurosis, with or without macular pseudocoloboma. Here, we report two patients: one compound heterozygous for IDH3A c.364G>A, p.(Ala122Thr), which has conflicting classifications, and for IDH3A c.293C>T, p.(Pro98Leu), which is likely pathogenic, and the other homozygous for IDH3A c.364G>A, p.(Ala122Thr). This study is aimed at providing evidence to link the latter variants to a clinical phenotype. The first patient was a 6-year-old girl, and the second patient was a 29-year-old female. In both patients, the diagnostic assessments were consistent with the phenotype of RP, characterized by macular pseudocoloboma but of varying severity. Patients’ phenotypes suggest that the c.293C>T, p.(Pro98Leu) variant is linked to a more severe and extensive clinical phenotype, while the c.364G>A, p.(Ala122Thr) variant results in a milder condition, primarily limited to retinal involvement. In Patient 2, the presence of both global and local stereopsis, indicating advanced visual development, suggests that the p.(Ala122Thr) missense variant may act as a hypomorphic allele which likely allows for some residual enzymatic activity of the IDH3A protein. This report highlights that macular pseudocoloboma can manifest even in the absence of a null variant. In contrast, more severe symptoms, such as mitochondrial encephalopathy, seem to be associated with the presence of a null allele. Furthermore, to the best of our knowledge, this is the first report of the IDH3A c.293C>T, p.(Pro98Leu) variant. Full article

Biallelic pathogenic variants in the CRB1 gene are associated with severe retinal dystrophies, including early onset severe retinal dystrophy/Leber congenital amaurosis (EOSRD/LCA), retinitis pigmentosa (RP), cone–rod dystrophy (CORD), and macular dystrophy (MD). Despite growing research, scant genotype–phenotype correlations have been established. Here, we present two cases involving individuals that presented with cystoid macular oedema and high intraocular pressure, which were later diagnosed as CRB1-MD, demonstrating a mild and stable phenotype. Two unrelated patients of African heritage were included, a 7-year-old female (case 1) and a 25-year-old female (case 2), both presenting with ocular hypertension and cystoid macular oedema. Case 2 had a history of bilateral plateau iris, treated with laser iridotomy. Baseline visual acuity for case 1 was 0.66 logMAR in the right eye and 0.54 logMAR in the left eye. For case 2, visual acuity was recorded as 0.30 logMAR in both eyes. Genetic testing confirmed a homozygous c.2506C>A p.(Pro836Thr) variant in the CRB1 gene in both cases. Longitudinal follow-up over seven years revealed stable visual acuity, improvement of cystoid macular oedema, and effective intraocular pressure control with topical ocular hypotensive therapy. This study establishes a novel genotype–phenotype correlation between the c.2506C>A p.(Pro836Thr) variant and MD, suggesting a mild, stable disease course in homozygous cases. The findings also highlight a potential association of this variant with elevated IOP, expanding the clinical spectrum of CRB1-related ocular conditions. Early genetic diagnosis and regular ophthalmic monitoring are essential to optimise management and identify therapeutic opportunities in patients with mild CRB1-related phenotypes. Full article

Degenerative and developmental eye disorders, including inherited retinal dystrophies (IRDs), anophthalmia, and congenital cataracts arise from genetic mutations, causing progressive vision loss or congenital structural abnormalities. IRDs include a group of rare, genetically, and clinically heterogeneous retinal diseases. It is caused by variations in at least 324 genes, affecting numerous retinal regions. In addition to IRDs, other developmental eye disorders such as anophthalmia and congenital cataracts also have a strong genetic basis. Autosomal recessive IRDs, anophthalmia, and congenital cataracts are common in consanguineous populations. In many endogamous populations, including those in Pakistan, a significant proportion of IRD and anophthalmia cases remain genetically undiagnosed. The present study investigated the variations in IRDs, anophthalmia, and congenital cataracts genes in 50 affected families. These unrelated consanguineous families were recruited from the different provinces of Pakistan including Punjab, Khyber Pakhtoon Khwa, Sindh, Gilgit Baltistan, and Azad Kashmir. Whole exome sequencing (WES) was conducted for the proband of each family. An in-house customized pipeline examined the data, and bioinformatics analysis predicted the pathogenic effects of identified variants. The relevant identified DNA variants of selected families were assessed in parents and healthy siblings via Sanger sequencing. WES identified 12 novel variants across 10 known IRD-associated genes. The four most frequently implicated genes were CRB1 (14.3%), GUCY2D (9.5%), AIPL1 (9.5%), and CERKL (7.1%) that together accounted for 40.4% of all molecularly diagnosed cases. Additionally, 25 reported variants in 19 known IRDs, anophthalmia, and congenital cataracts-associated genes were found. Among the identified variants, p. Trp278X, a stop–gain mutation in the AIPL1 (NM_014336) gene, was the most common causative variant detected. The most frequently observed phenotype was retinitis pigmentosa (46.5%) followed by Leber congenital amaurosis (18.6%). Furthermore, 98% of pedigrees (49 out of 50) were affected by autosomal recessive IRDs, anophthalmia and congenital cataracts. The discovery of 12 novel likely pathogenic variants in 10 IRD genes, 25 reported variants in 19 known IRDs, anophthalmia and congenital cataracts genes, atypical phenotypes, and inter and intra-familial variability underscores the genetic and phenotypic heterogeneity of developmental and degenerative eye disorders in the Pakistani population and further expands the mutational spectrum of genes associated with these ocular disorders. Full article

Mitochondria are vital organelles responsible for ATP production and metabolic regulation, essential for energy-intensive cells such as retinal ganglion cells. Dysfunction in mitochondrial oxidative phosphorylation or mitochondrial DNA (mtDNA) pathogenic variants can disrupt ATP synthesis, cause oxidative stress, and lead to cell death. This has profound implications for tissues such as the retina, optic nerve, and retinal pigment epithelium, which are dependent on robust mitochondrial function. In this review, we provide a comprehensive compilation of pathogenic variants in the mtDNA associated with various ophthalmic diseases, including Leber’s hereditary optic neuropathy, chronic progressive external ophthalmoplegia, Leigh syndrome, mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes, among others. We highlight the genetic variants implicated in these conditions, their pathogenic roles, and the phenotypic consequences of mitochondrial dysfunction in ocular tissues. In addition to well-established mutations, we also discuss the emerging evidence of the role of mtDNA’s variants in complex multifactorial diseases, such as non-arteritic anterior ischemic optic neuropathy, primary open-angle glaucoma, and age-related macular degeneration. The review aims to serve as a valuable resource for clinicians and researchers, providing a detailed overview of mtDNA pathogenic variants and their clinical significance in the context of mitochondrial-related eye diseases. Full article

Background/Objectives: Leber hereditary optic neuropathy (LHON) is often misdiagnosed in its early stages as idiopathic single isolated optic neuritis (SION) or multiple-sclerosis-associated optic neuritis (MS-ON) due to the young age of the patients, the subacute vision loss, and the central visual field defect. The aim of this retrospective study was to evaluate changes in the peripapillary RNFL and GCLT over time in patients with early LHON, MS-ON, and SION in order to differentiate Leber hereditary optic neuropathy (LHON) from optic neuritis (ON) in the early stages of the disease. Methods: Patients with LHON and ON (either idiopathic single isolated optic neuritis (SION) or ON as the first symptom of relapsing–remitting multiple sclerosis (MS-ON) were included. Optical coherence tomography (OCT) scans were reviewed. The inclusion criteria were at least one follow-up OCT examination and a definite diagnosis after examination. Changes in the peripapillary retinal nerve fibre layer (RNFL) and macular ganglion cell layer thickness (GCLT) in both groups were evaluated over time and compared with normative data. The analysis focused on the early phase (0–45 days) after symptom onset. Results: Nine LHON patients with early OCT scans and twenty patients with ON were included. Quantitative OCT analysis showed greater RNFL swelling in LHON compared to ON during the first 60 days after symptom onset. Between day 61 and day 120, subnormal RNFL values were observed in both groups compared to controls. Thereafter, the RNFL decreased continuously and severely in the LHON group. The RNFL of ON patients did not show a clear progression after day 120. The GCLT in five LHON eyes showed a strong and solid decrease from day 0 to day 45, which was stronger than the moderate atrophy measured in ON eyes. Continuous GCL atrophy was measured until day 121 in LHON, after which a floor effect was reached. The GCLT in the inner nasal and inner inferior sectors was significantly smaller in LHON compared to ON patients on days 0–45. Conclusions: Thinning of the GCLT occurs at an early stage in LHON patients. Thus, GCLT may become a diagnostic tool to differentiate LHON from ON in the early phase of disease. Full article