Oculocutaneous albinism (OCA) are genetically and clinically heterogeneous recessive disorders with at least 23 associated genes. Isolated OCA is characterized by hypopigmentation in the skin, hair, and eyes combined with ocular abnormalities. Hermansky Pudlak syndrome (HPS) and Chediak-Higaski syndrome are syndromic forms of OCA, distinguished by immunological and hematological symptoms in addition to hypopigmentation and ocular anomalies. Targeted clinical care is crucial for the patients and molecular genetic diagnosis is important for classification of patients. Current diagnostic yield is approximately 70%, and a high proportion of patients are heterozygous for pathogenic variants in OCA genes, suggesting the presence of disease-causing non-coding variants. We describe here next generation sequencing (NGS) analysis, including copy number variant (CNV) analysis, of 28 consanguineous families, comprising a total of 136 individuals presenting with OCA. We provide a molecular genetic diagnosis in all 28 families. Noteworthy, five families (18%) had pathogenic variants in a gene associated with HPS, showing the importance of an in-depth molecular genetic investigation, which should be offered to persons with albinism. Furthermore, we report the first deep intron variant in TYR causing OCA and show by minigene analysis that the variant causes inclusion of a pseudoexon.
Hereditary optic atrophy is characterized by degeneration of retinal ganglion cells and may result from a wide range of genetic etiologies. While pathogenic variants in OPA1 and primary mitochondrial variants causing Leber hereditary optic neuropathy (LHON) account for a substantial proportion of cases, many patients remain genetically unsolved. We evaluated the diagnostic yield and clinical impact of comprehensive whole exome/genome sequencing (WES/WGS)-based virtual panel testing in 62 partially pre-screened individuals with suspected hereditary optic atrophy. A total of 51 genes associated with optic atrophy and mitochondrial DNA variants were analyzed. Clinical data were systematically retrieved from medical records, including information on extraocular manifestations. A genetic diagnosis was established in 21 patients (33.9%). Pathogenic or likely pathogenic variants in OPA1 accounted for 57.1% of solved cases, whereas 42.9% involved other genes, including WFS1, ACO2, NR2F1, UCHL1, CACNA1F, and COQ2. In the majority of patients with non-OPA1 findings, the genetic diagnosis prompted additional clinical evaluation, surveillance, or therapeutic intervention. Our findings demonstrate that broad WES/WGS-based testing increases diagnostic yield and expands the genetic spectrum beyond OPA1 and LHON, frequently revealing syndromic conditions with direct clinical implications. Comprehensive genomic testing with broader gene panels should therefore be considered part of the diagnostic workup when hereditary optic atrophy is suspected.
PURPOSE:To provide the first comprehensive, overview of the Danish Family Archive for Genetic Eye Diseases, a national umbrella registry on inherited eye disorders initiated in 1985. METHODS:A cross-sectional extraction of entries collected over 40 years was performed on 1 May 2025. Core variables included family identifier, clinical diagnosis, and genetic results. Descriptive statistics were generated within a secure registry environment. RESULTS:The registry contained 10,377 affected individuals from 3,412 unique families. Seventy-four distinct clinical diagnoses were documented; retinitis pigmentosa (1,709 cases) was the most frequent, followed by congenital cataract (1,220), autosomal dominant optic atrophy (1,077), congenital stationary night blindness (649) and Stargardt disease (555). Genetic data revealed 260 different disease-associated genes, the most prevalent being OPA1 (318 cases), ABCA4 (276), and USH2A (150). A confirmed genetic etiology was established for 2 972 individuals (28.6%) and in 2,052 families (60.9%). Syndromic involvement was recorded in 13%. CONCLUSIONS:The Danish Family Archive offers an unparalleled, nationwide overview of inherited eye disorders, confirming substantial diagnostic and genotypic heterogeneities. The registry data already accelerate clinical work-up and precision genetic counseling and enable rapid identification of well phenotyped and genotyped candidates for emerging therapies and clinical trials.
IntroductionOptic disc drusen (ODD) are believed to have a genetic predisposition, with autosomal dominant inheritance pattern with incomplete penetrance suggested through family pedigree analysis. ODD prevalence is higher in certain genetic disorders, such as pseudoxanthoma elasticum and retinitis pigmentosa. This study aimed to identify candidate genes potentially involved in the development of ODD.MethodsFamily members aged 18 years or older from families with ODD were included. Participants underwent optical coherence tomography of the optic nerve head, and blood samples were collected for whole-genome sequencing using the Illumina NovaSeq 6000 platform. Single nucleotide variants were identified with the Genome Analysis Toolkit (GATK) and filtered in VarSeq using a population frequency threshold of 1%. Selected genes were classified according to ACMG guidelines.ResultsA total of 10 families were included, three of which had more than two affected members. Thirty-three variants were identified, with the following genes selected for description: ABCC6, DDX50, TREX1, PLCB4, PTPRQ, LBR, RP1L1, and KRT3. The identified candidate genes showed a wide range of functions and are associated with different disorders. Of particular interest is ABCC6, which normally inhibits ectopic calcification.ConclusionWe identified a list of candidate genes. Studies including larger ODD families are necessary to identify robust candidate genes.
PURPOSE:Cancer predisposition syndromes (CPS) with pediatric onset are the leading known cause of childhood malignancies and are increasingly guiding clinical strategies in pediatric oncology. CPS are placed under evolutionary negative selective pressure, but pediatric pancancer studies have so far failed to investigate genomic evolutionary metrics as a guide to predict penetrance and reveal novel CPS. EXPERIMENTAL DESIGN:Germline whole-genome sequencing was performed in a 5-year prospective, registry-validated, nationwide cohort of individuals diagnosed with cancer before age 18. Evolution-guided burden analysis of private germline variants in constrained genes was compared with 125,748 gnomAD exomes. RESULTS:Across a total of 1,127 participants, 16% carried a pathogenic variant in at least one CPS gene. After genotype-phenotype matching, 9% of children in the prospective cohort (n = 651) carried a variant considered causative, a rate deemed significantly higher than in previous studies [RR, 1.54, 95% confidence interval (CI), 1.37-1.75, P = 1 × 10-14]. As predicted for a disease subject to negative Darwinian selective pressure, compared with reference adults, we found a significant excess of loss-of-function (LoF) variants in the 1,500 most constrained genes (RR, 1.54, 99% CI, 1.21-1.95, P = 4 × 10-6). Surprisingly, this excess was greater than expected, leaving a significant residual enrichment of predicted LoF variants in genes evolutionarily considered the least tolerant to damage (RR, 1.41, 99% CI, 1.09-1.80, P = 4 × 10-4). CONCLUSIONS:The high frequency of LoF variants, including in known CPS, emphasizes the need for systematic and extensive germline genomic mapping as part of the diagnostic workup of patients with childhood cancer and the linkage of such data to disease and response phenotypes to guide future pediatric oncological care and ultimately pave the way for prediagnostic interventional measures.
Maternal uniparental disomy of chromosome 14, upd(14)mat, leads to Temple syndrome (TS), an imprinting disorder characterized by pre- and postnatal growth retardation, hypotonia, motor delay, joint laxity, and precocious puberty. The occurrence of upd(14)mat is rare, and it may, in even rarer cases, co-occur with trisomy 14 mosaicism. To date, only 11 live-born cases have been reported in the literature. We present a newborn girl with severe hypotonia, global developmental delay, feeding difficulties, dysmorphic features, and cardiac malformations. Using trio whole genome sequencing (WGS) no causative sequence or structural variants were detected. As a chromosomal disorder was suspected the data was further analyzed with a pipeline including analysis of UPD and low-level mosaicism, which revealed upd(14)mat and low level trisomy 14 mosaicism. This study underscores the significance of advanced genetic testing techniques, thorough data interpretation, and expert clinical evaluation in diagnosing rare disorders with complex molecular mechanisms.
PURPOSE:To examine the long-term risk of glaucoma after cataract surgery in childhood. METHODS:This study took place from January 2022 until December 2022 and included patients from a large family with hereditary childhood cataract who had cataract surgery before 18 years of age. Patients underwent an ophthalmologic examination to determine the presence of glaucoma or ocular hypertension (OHT). Patients who did not want to participate in the examination could contribute with a medical journal from their treating ophthalmologist. The risk of long-term glaucoma was determined using survival analysis, and risk factors were assessed using a Cox proportional hazards regression model. RESULTS:We included 68 patients (133 eyes) with a median age at cataract surgery of 7 years (IQR: 5-10). The median follow-up time after cataract surgery to glaucoma/OHT or the latest ophthalmologic examination was 35 years (IQR: 15-48). Twelve patients (18 eyes) had glaucoma, and five patients (eight eyes) had OHT, resulting in 15 patients with glaucoma/OHT. The long-term risk of glaucoma/OHT diagnosed in adulthood was 47.7% (CI: 21.8-70.9) at the age of 70 years of patients who were free of glaucoma before their 18th year. We could not confirm or dismiss an association between glaucoma/OHT and sex, age at surgery, number of ocular interventions before 18 years of age or glaucoma after cataract surgery in a first-degree relative. CONCLUSION:Cataract surgery in childhood is associated with a high risk of late-onset glaucoma. Regular lifelong follow-up is important to ensure early diagnosis and prevent extensive vision loss.
IntroductionRetinitis pigmentosa (RP) is a group of inherited retinal dystrophies characterized by progressive photoreceptor degeneration. In a recent study, we reported co-existing optic disc drusen (ODD) at 30%, a prevalence 15 times higher than in the general population. The aims of this study were to a) assess if macular retinal nerve fiber layer thickness (RNFLt) was increased in our cohort of RP patients and b) compare RNFLt between RP patients with and without ODD.MethodsIn this post-hoc analysis, optical coherence tomography (OCT) scans of patients with RP and healthy controls were manually delineated, and macular RNFLt measurements were obtained. The analyses were conducted both a) for RP patients without ODD compared to controls and b) for RP patients with and without ODD.ResultsOCT scans of 32 patients with RP and 13 healthy controls were included. Macular RNFLt was significantly increased in RP patients compared to healthy controls and in RP patients with ODD compared to RP patients without ODD.DiscussionFurther studies will explore whether increased RNFLt leads to ODD development through dystrophic calcification or, conversely, if ODD in combination with RP-associated retinal ganglion cell damage causes the increased RNFLt through retrograde axoplasmic stasis.
PURPOSE:To describe the phenotype of Danish patients with genetically verified achromatopsia (ACHM) with special focus on signs of progression on structural or functional parameters, and possible genotype-phenotype correlations. METHODS:Forty-eight patients were identified, with disease-causing variants in five different genes: CNGA3, CNGB3, GNAT2, PDE6C and PDE6H. Longitudinal evaluation was possible for 11 patients and 27 patients participated in a renewed in-depth phenotyping consisting of visual acuity assessment, optical coherence tomography (OCT), fundus autofluorescence, colour vision evaluation, contrast sensitivity, mesopic microperimetry and full-field electroretinography. Foveal morphology was evaluated based on OCT images for all 48 patients using a grading system based on the integrity of the hyperreflective photoreceptor band, the inner segment ellipsoid zone (ISe). Signs of progression were evaluated based on longitudinal data and correlation with age. RESULTS:We found a statistically significant positive correlation between OCT grade and age (Spearman ρ = 0.62, p < 0.0001) and we observed changes in the foveal morphology in 2 of 11 patients with ≥5 years of follow-up. We did not find any convincing correlation between age and functional parameters (visual acuity, retinal sensitivity and contrast sensitivity) nor did we find correlation between structural and functional parameters, or any clear genotype-phenotype correlation. CONCLUSIONS:Some patients with ACHM demonstrate signs of progressive foveal changes in OCT characteristics with increasing age. This is relevant in terms of possible new treatments. However, functional characteristics, such as visual acuity, remained stable despite changing foveal structure. Thus, seen from a patient perspective, ACHM can still be considered a non-progressive condition.
Optic disc drusen (ODD) may present in multiple individuals and generations within a family, indicating hereditary predisposition. Individuals are often unaware of their ODD, and consequently, the prevalence of ODD within families remains largely unknown. The aim of this study was to estimate the prevalence and consider the inheritance pattern of familial ODD and to investigate ODD-related symptoms and their association to ODD location and size. In this cross-sectional study, 22 ODD patients, aged 10 years or older, were included. Of these, 13 ODD probands had 24 family members participating. The presence, size, and anatomical location of ODDs and the presence of hyperreflective lines were ascertained using enhanced depth imaging optical coherence tomography (EDI-OCT) scan. Visual symptoms were ascertained, and these were correlated with ODD burden in terms of ODD location and size. Familial ODD was found in eight of the 13 screened families. Hyperreflective lines were present in all individuals with ODD, including both probands and their family members, and in seven out of the 14 family members without ODD. Visual symptoms were reported in 14-50% and associated significantly with superficial ODD location. We found familial ODD in eight of the 13 screened families. Our results aligned with the previously suggested autosomal dominant inheritance pattern with incomplete penetrance, assuming that hyperreflective lines represent a less expressed form of ODD. This emphasizes that ODD runs in families and supports the hypothesis that genetic factors may contribute to the etiology.
Gain-of-function variants in GFAP leads to protein aggregation and is the cause of the severe neurodegenerative disorder Alexander Disease (AxD), while loss of GFAP function has been considered benign. Here, we investigated a six-generation family, where multiple individuals presented with gliosis of the optic nerve head and visual impairment. Whole genome sequencing (WGS) revealed a frameshift variant in GFAP (c.928dup, p.(Met310Asnfs*113)) segregating with disease. Analysis of human embryonic tissues revealed strong expression of GFAP in retinal neural progenitors. A zebrafish model verified that c.928dup does not result in extensive GFAP protein aggregation and zebrafish gfap loss-of-function mutants showed vision impairment and retinal dysplasia, characterized by a significant loss of M & uuml;ller glia cells and photoreceptor cells. Our findings show how different mutational mechanisms can cause diverging phenotypes and reveal a novel function of GFAP in vertebrate eye development.
Achromatopsia is a rare congenital condition with cone photoreceptor dysfunction causing color blindness, reduced vision, nystagmus and photophobia. New treatments are being developed, but the current evidence is still conflicting regarding possible progression over time, and there is no clear genotype-phenotype correlation. This natural history study aimed to further explore the course of disease and potential clinical differences between various genotypes. The retrospective design allowed for the study of a large cohort with a long follow-up. Patients were identified from the Danish national registries. If not already available, genetic analysis was offered to the patient. Clinical data from 1945-2022 were retrieved from medical records and included best-corrected visual acuity (BCVA), color vision, refractive error, nystagmus, visual fields and fundoscopic findings. We identified variants believed to be disease causing in five of the known achromatopsia genes: CNGA3; CNGB3; GNAT2; PDE6C and PDE6H; and novel variants were identified in CNGB3 and PDE6C. Progressive deterioration of BCVA only attributable to achromatopsia was found in three of 58 patients. Progressive phenotype was seen with variants in CNGB3 and PDE6C. The results indicate that myopia could be more frequently occurring with variants in GNAT2, PDE6C and PDE6H and support the evidence that achromatopsia is a predominantly stationary condition with respect to BCVA. Although a clear genotype-phenotype correlation can still not be concluded, there may be differences in phenotypical characteristics with variants in different genes.
Background/aim: To describe the clinical phenotype of retinitis pigmentosa (RP) caused by PRPF31-variants and clinical characterization of asymptomatic PRPF31 carriers. Materials and methods: We conducted a descriptive cross-sectional deep phenotyping study. We included subjects with PRPF31 variants predicted to be disease-causing, both individuals with RP and asymptomatic carriers. Participants underwent a comprehensive clinical examination of standard visual function parameters (visual acuity, contrast sensitivity, Goldmann visual field), full-field stimulus threshold (FST), full-field electroretinogram (ff-ERG), and a structural investigation with slit lamp and multimodal imaging. We used Spearman correlation analyses to evaluate associations between quantitative outcomes. Results: We included 21 individuals with disease-causing PRPF31-variants: 16 symptomatic and 5 asymptomatic subjects. The symptomatic subjects demonstrated a typical RP phenotype with constricted visual fields, extinguished ff-ERG, and disrupted outer retinal anatomy. FST was impaired and correlated significantly with other outcome measures in RP subjects. Structure-function correlations with Spearman correlation analysis showed moderate correlation coefficients due to a few outliers in each analysis. The asymptomatic individuals had normal best-corrected visual acuity and visual fields, but showed reduced ff-ERG amplitudes, borderline FST sensitivity, and structural abnormalities on OCT and fundoscopy. Conclusions: RP11 has a typical RP phenotype but varies in terms of severity. FST measurements correlated well with other functional and structural metrics and may be a reliable outcome measure in future trials as it is sensitive to a broad range of disease severities. Asymptomatic carriers showed subclinical disease manifestations, and our findings underline that reported non-penetrance in PRPF31-related RP is not an all-or-none phenomenon.
Background Studies suggest that Wilms tumours (WT) are caused by underlying genetic (5%-10%) and epigenetic (2%-29%) mechanisms, yet studies covering both aspects are sparse.Methods We performed prospective whole-genome sequencing of germline DNA in Danish children diagnosed with WT from 2016 to 2021, and linked genotypes to deep phenotypes.Results Of 24 patients (58% female), 3 (13%, all female) harboured pathogenic germline variants in WT risk genes (FBXW7, WT1 and REST). Only one patient had a family history of WT (3 cases), segregating with the REST variant. Epigenetic testing revealed one (4%) additional patient (female) with uniparental disomy of chromosome 11 and Beckwith-Wiedemann syndrome (BWS). We observed a tendency of higher methylation of the BWS-related imprinting centre 1 in patients with WT than in healthy controls. Three patients (13%, all female) with bilateral tumours and/or features of BWS had higher birth weights (4780 g vs 3575 g; p=0.002). We observed more patients with macrosomia (>4250 g, n=5, all female) than expected (OR 9.98 (95% CI 2.56 to 34.66)). Genes involved in early kidney development were enriched in our constrained gene analysis, including both known (WT1, FBXW7) and candidate (CTNND1, FRMD4A) WT predisposition genes. WT predisposing variants, BWS and/or macrosomia (n=8, all female) were more common in female patients than male patients (p=0.01).Conclusion We find that most females (57%) and 33% of all patients with WT had either a genetic or another indicator of WT predisposition. This emphasises the need for scrutiny when diagnosing patients with WT, as early detection of underlying predisposition may impact treatment, follow-up and genetic counselling.
Background: Studies of patients with retinitis pigmentosa (RP) have reported an increased prevalence of optic disc drusen (ODD) compared with the ODD prevalence in the general population. The diagnostic gold standard method for identifying ODD is enhanced depth imaging optical coherence tomography (EDI-OCT), but this modality has not previously been used systematically for identifying ODD in patients with RP. This study aimed to estimate the prevalence of ODD in patients with RP using EDI-OCT. Methods: In this cross-sectional study, 40 patients with clinically diagnosed RP aged 18 years or older were included. All patients underwent an ophthalmic examination, including kinetic perimetry, EDI-OCT of the optic nerve head, and fundus photography. Genetic testing with a next-generation sequencing panel of retinal dystrophy genes was performed on the RP patients without a prior genetic diagnosis. Results: Twelve patients (30.0%) had at least one ODD. Six patients had bilateral ODD. No significant differences between patients with and without ODD were found according to age, refraction, best-corrected visual acuity, Bruch membrane opening, or visual field. The genetic variation causing RP was found in 11 of 12 cases in the ODD group and in 17 of 28 cases in the group without ODD. Conclusions: We found the prevalence of ODD in patients with RP to be 30.0%. This is 15 times higher than in the general population and much higher than previously estimated in most studies, potentially indicating that the 2 conditions might be pathogenically related.
We present a novel, fully three-dimensional approach to soft material characterization and constitutive modeling with relevance to soft biological tissue. Our approach leverages recent advances in experimental techniques and data-driven computation. The experimental component of this approach involves in situ mechanical loading in a magnetic field (using MRI), yielding the entire deformation tensor field throughout the specimen regardless of the possible irregularities in its three-dimensional shape. Characterization can therefore be accomplished with data at a reduced number of deformation states. We refer to this experimental technique as MR-u. Its combination with powerful approaches to inverse modelling, specifically methods of model inference, would open the door to insightful mechanical characterization for soft materials. In recent computational advances that answer this need, we have developed new, data-driven inverse techniques to infer the model that best explains the physics governing observed phenomena from a spectrum of admissible ones, while maintaining parsimony of representation. This approach is referred to as Variational System Identification (VSI). In this communication, we apply the MR–u approach to characterize soft polymers regarding them as surrogates of soft biological tissue, and using VSI, we infer the physically best-suited and parsimonious mathematical models of their mechanical response. We demonstrate the performance of our methods in the face of noisy data with physical constraints that challenge the identification of mathematical models, while attaining high accuracy in the predicted response of the inferred models.
(1) Background/aims: To examine potential genetic modifiers of disease penetrance in PRPF31-associated retinitis pigmentosa 11 (RP11). (2) Methods: Blood samples from individuals (n = 37) with PRPF31 variants believed to be disease-causing were used for molecular genetic testing and, in some cases (n = 23), also for mRNA expression analyses. Medical charts were used to establish if individuals were symptomatic (RP) or asymptomatic non-penetrant carriers (NPC). RNA expression levels of PRPF31 and CNOT3 were measured on peripheral whole blood using quantitative real-time PCR normalized to GAPDH. Copy number variation of minisatellite repeat element 1 (MSR1) was performed with DNA fragment analysis. (3) Results: mRNA expression analyses on 22 individuals (17 with RP and 5 non-penetrant carriers) revealed no statistically significant differences in PRPF31 or CNOT3 mRNA expression levels between individuals with RP and non-penetrant carriers. Among 37 individuals, we found that all three carriers of a 4-copy MSR1 sequence on their wild-type (WT) allele were non-penetrant carriers. However, copy number variation of MSR1 is not the sole determinant factor of non-penetrance, as not all non-penetrant carriers carried a 4-copy WT allele. A 4-copy MSR1 mutant allele was not associated with non-penetrance. (4) Conclusions: In this Danish cohort, a 4-copy MSR1 WT allele was associated with non-penetrance of retinitis pigmentosa caused by PRPF31 variants. The level of PRPF31 mRNA expression in peripheral whole blood was not a useful indicator of disease status.