Genetic epidemiology of inherited retinal diseases in a large patient cohort followed at a single center in Italy.

Inherited retinal diseases (IRDs) are the leading cause of vision loss in the working-age population. We performed a retrospective epidemiological study to determine the genetic basis of IRDs in a large Italian cohort (n = 2790) followed at a single referral center. We provided, mainly by next generation sequencing, potentially conclusive molecular diagnosis for 2036 patients (from 1683 unrelated families). We identified a total of 1319 causative sequence variations in 132 genes, including 353 novel variants, and 866 possibly actionable genotypes for therapeutic approaches. ABCA4 was the most frequently mutated gene (n = 535; 26.3% of solved cases), followed by USH2A (n = 228; 11.2%) and RPGR (n = 102; 5.01%). The other 129 genes had a lower contribution to IRD pathogenesis (e.g. CHM 3.5%, RHO 3.5%; MYO7A 3.4%; CRB1 2.7%; RPE65 2%, RP1 1.8%; GUCY2D 1.7%). Seventy-eight genes were mutated in five patients or less. Mitochondrial DNA variants were responsible for 2.1% of cases. Our analysis confirms the complex genetic etiology of IRDs and reveals the high prevalence of ABCA4 and USH2A mutations. This study also uncovers genetic associations with a spectrum of clinical subgroups and highlights a valuable number of cases potentially eligible for clinical trials and, ultimately, for molecular therapies.

Applications of Optical Coherence Tomography in the Ocular Diagnosis: From the Tear Film to the Sclera.

The latest technological developments have radically impacted the daily practice of ophthalmologists, thanks to the advent of novel diagnostic tools that facilitate an early diagnosis and allow a better management of ocular disorders [...].

RPE65-Associated Retinopathies in the Italian Population: A Longitudinal Natural History Study.

Purpose: To investigate the course of inherited retinal degenerations (IRD) due to mutations in the RPE65 gene. Methods: This longitudinal multicentric retrospective chart-review study was designed to collect best corrected visual acuity (BCVA), Goldman visual field, optical coherence tomography (OCT), and electroretinography (ERG) measurements. The data, including imaging, were collected using an electronic clinical research form and were reviewed at a single center to improve consistency. Results: From an overall cohort of 60 Italian patients with RPE65-associated IRD, 43 patients (mean age, 27.8 ± 19.7 years) were included and showed a mean BCVA of 2.0 ± 1.0 logMAR. Time-to-event analysis revealed a median age of 33.8 years and 41.4 years to reach low vision and blindness based on BCVA, respectively. ERG (available for 34 patients) showed undetectable responses in most patients (26; 76.5%). OCT (available for 31 patients) revealed epiretinal membranes in five patients (16.1%). Central foveal thickness significantly decreased with age at a mean annual rate of -0.6%/y (P = 0.044). We identified 43 different variants in the RPE65 gene in the entire cohort. Nine variants were novel. Finally, to assess genotype-phenotype correlations, patients were stratified according to the number of RPE65 loss-of-function (LoF) alleles. Patients without LoF variants showed significantly (P < 0.05) better BCVA compared to patients with one or two LoF alleles. Conclusions: We described the natural course of RPE65-associated IRD in an Italian cohort showing for the first time a specific genotype-phenotype association. Our findings can contribute to a better management of RPE65-associated IRD patients.

Liver-Directed Adeno-Associated Virus-Mediated Gene Therapy for Mucopolysaccharidosis Type VI.

BACKGROUND: Mucopolysaccharidosis type VI (MPS VI) is an inherited multisystem lysosomal disorder due to arylsulfatase B (ARSB) deficiency that leads to widespread accumulation of glycosaminoglycans (GAG), which are excreted in increased amounts in urine. MPS VI is characterized by progressive dysostosis multiplex, connective tissue and cardiac involvement, and hepatosplenomegaly. Enzyme replacement therapy (ERT) is available but requires life-long and costly intravenous infusions; moreover, it has limited efficacy on diseased skeleton and cardiac valves, compromised pulmonary function, and corneal opacities. METHODS: We enrolled nine patients with MPS VI 4 years of age or older in a phase 1/2 open-label gene therapy study. After ERT was interrupted, patients each received a single intravenous infusion of an adeno-associated viral vector serotype 8 expressing ARSB. Participants were sequentially enrolled in one of three dose cohorts: low (three patients), intermediate (two patients), or high (four patients). The primary outcome was safety; biochemical and clinical end points were secondary outcomes. RESULTS: The infusions occurred without severe adverse events attributable to the vector, meeting the prespecified end point. Participants in the low and intermediate dose cohorts displayed stable serum ARSB of approximately 20% of the mean healthy value but returned to ERT by 14 months after gene therapy because of increased urinary GAG. Participants in the high-dose cohort had sustained serum ARSB of 30% to 100% of the mean healthy value and a modest urinary GAG increase that did not reach a concentration at which ERT reintroduction was needed. In the high-dose group, there was no clinical deterioration for up to 2 years after gene therapy. CONCLUSIONS: Liver-directed gene therapy for participants with MPS VI did not have a dose-limiting side-effect and adverse event profile; high-dose treatment resulted in ARSB expression over at least 24 months with preliminary evidence of disease stabilization. (Funded by the Telethon Foundation ETS, the European Commission Seventh Framework Programme, and the Isaac Foundation; ClinicalTrials.gov number, NCT03173521; EudraCT number, 2016-002328-10.)

Voretigene Neparvovec Gene Therapy in Clinical Practice: Treatment of the First Two Italian Pediatric Patients.

Purpose: To present visual outcomes of the first two Italian patients with RPE65-related inherited retinal dystrophy (RPE65-IRD) treated with voretigene neparvovec (VN). Methods: Two pediatric patients with RPE65-IRD were treated with VN in both eyes. Patients were evaluated by best-corrected visual acuity (BCVA), full-field stimulus threshold (FST) test, semiautomated kinetic visual field (SKVF), microperimetry, and chromatic pupillometry over 6 months. Results: No complications occurred in the first patient, whereas in the second a subretinal hemorrhage was observed in the first treated eye, and excessive resistance to drug injection occurred during treatment of the second eye. BCVA improved by at least one Early Treatment Diabetic Retinopathy Study line in all treated eyes. The FST test and SKVF showed clinically significant improvements in all eyes (i.e., change of light sensitivity > 10 decibels; area enlargement of at least 20%). Moreover, microperimetry showed better fixation stability. Finally, chromatic pupillometry showed increases in pupillary constriction that ranged from 10% to 20%. All visual changes remained stable during follow-up. Conclusions: The first VN treatments in two pediatric Italian patients in clinical practice showed significant improvements in visual outcomes, even in the case of surgical complications, which spontaneously recovered without sequelae. Translational Relevance: These findings with VN in patients with RPE65-IRD confirm the results of clinical trials.

Mild Clinical Presentation of Joubert Syndrome in a Male Adult Carrying Biallelic MKS1 Truncating Variants.

Pathogenic variants in the MKS1 gene are responsible for a ciliopathy with a wide spectrum of clinical manifestations ranging from Meckel and Joubert syndrome (JBTS) to Bardet-Biedl syndrome, and involving the central nervous system, liver, kidney, skeleton, and retina. We report a 39-year-old male individual presenting with isolated Retinitis Pigmentosa (RP), as assessed by full ophthalmological evaluation including Best-Corrected Visual Acuity measurements, fundus examination, Goldmann Visual Field test, and full-field Electroretinography. A clinical exome identified biallelic nonsense variants in MKS1 that prompted post-genotyping investigations for systemic abnormalities of ciliopathy. Brain magnetic resonance imaging revealed malformations of the posterior cranial fossa with the 'molar tooth sign' and cerebellar folia dysplasia, which are both distinctive features of JBTS. No other organ or skeletal abnormalities were detected. This case illustrates the power of clinical exome for the identification of the mildest forms of a disease spectrum, such as a mild JBTS with RP in the presented case of an individual carrying biallelic truncating variants in MKS1.

Spectrum of Disease Severity in Nonsyndromic Patients With Mutations in the CEP290 Gene: A Multicentric Longitudinal Study.

Purpose: The purpose of this study was to perform a detailed longitudinal phenotyping and genetic characterization of 32 Italian patients with a nonsyndromic retinal dystrophy and mutations in the CEP290 gene. Methods: We reviewed the clinical history and examinations of 32 patients with a nonsyndromic retinal dystrophy due to mutations in the CEP290 gene, followed up (mean follow-up: 5.9 years) at 3 Italian centers. The clinical examinations included: best corrected visual acuity (BCVA), optical coherence tomography (OCT), and full-field electroretinogram (ERG). Results: Patients (mean age = 19.0 ± 3.4 years) had a mean BCVA of 1.73 ± 0.20 logMAR. Longitudinal analysis of BCVA showed a nonsignificant decline. Central retinal thickness (CRT) declined significantly with age at an exponential rate of 1.0%/year (P = 0.001). At disease onset, most patients (19/32; 49.4%) had nystagmus. The absence of nystagmus was significantly associated with better BCVA and more preserved CRT (P < 0.05). ERG showed undetectable responses in most patients (64.0%), whereas reduced scotopic and photopic responses were observed in four patients (16.0%) who had no nystagmus. We identified 35 different variants, among which 12 were novel. Our genotype-phenotype correlation analysis shows a significantly worse BCVA in patients harboring a loss-of-function mutation and the deep-intronic variant c.2991+1655A>G. Conclusions: Our study highlights a mild phenotype of the disease, characterized by absence of nystagmus, good visual acuity, considerably preserved retinal morphology, and recordable ERG, confirming the wide spectrum of CEP290-related retinal dystrophies. Finally, in our cohort, the deep intronic variant c.2991+1655A>G was associated with a more severe phenotype.

Clinical and Molecular Characterization of Achromatopsia Patients: A Longitudinal Study.

Achromatopsia (ACHM) is a rare genetic disorder of infantile onset affecting cone photoreceptors. To determine the extent of progressive retinal changes in achromatopsia, we performed a detailed longitudinal phenotyping and genetic characterization of an Italian cohort comprising 21 ACHM patients (17 unrelated families). Molecular genetic testing identified biallelic pathogenic mutations in known ACHM genes, including four novel variants. At baseline, the patients presented a reduced best corrected visual acuity (BCVA), reduced macular sensitivity (MS), normal dark-adapted electroretinogram (ERG) responses and undetectable or severely reduced light-adapted ERG. The longitudinal analysis of 16 patients (mean follow-up: 5.4 ± 1.0 years) showed a significant decline of BCVA (0.012 logMAR/year) and MS (-0.16 dB/year). Light-adapted and flicker ERG responses decreased below noise level in three and two patients, respectively. Only two patients (12.5%) progressed to a worst OCT grading during the follow-up. Our findings corroborate the notion that ACHM is a progressive disease in terms of BCVA, MS and ERG responses, and affects slowly the structural integrity of the retina. These observations can serve towards the development of guidelines for patient selection and intervention timing in forthcoming gene replacement therapies.

Spectrum of Disease Severity in Patients With X-Linked Retinitis Pigmentosa Due to RPGR Mutations.

Purpose: The purpose of this study was to perform a detailed longitudinal phenotyping of X-linked retinitis pigmentosa (RP) caused by mutations in the RPGR gene during a long follow-up period. Methods: An Italian cohort of 48 male patients (from 31 unrelated families) with RPGR-associated RP was clinically assessed at a single center (mean follow-up = 6.5 years), including measurements of best-corrected visual acuity (BCVA), Goldmann visual field (GVF), optical coherence tomography (OCT), fundus autofluorescence (FAF), microperimetry, and full-field electroretinography (ERG). Results: Patients (29.6 ± 15.2 years) showed a mean BCVA of 0.6 ± 0.7 logMAR, mostly with myopic refraction (79.2%). Thirty patients (62.5%) presented a typical RP fundus, while the remaining sine pigmento RP. Over the follow-up, BCVA significantly declined at a mean rate of 0.025 logMAR/year. Typical RP and high myopia were associated with a significantly faster decline of BCVA. Blindness was driven primarily by GVF loss. ERG responses with a rod-cone pattern of dysfunction were detectable in patients (50%) that were significantly younger and more frequently presented sine pigmento RP. Thirteen patients (27.1%) had macular abnormalities without cystoid macular edema. Patients (50%) with a perimacular hyper-FAF ring were significantly younger, had a higher BCVA and a better-preserved ellipsoid zone band than those with markedly decreased FAF. Patients harboring pathogenic variants in exons 1 to 14 showed a milder phenotype compared to those with ORF15 mutations. Conclusions: Our monocentric, longitudinal retrospective study revealed a spectrum disease progression in male patients with RPGR-associated RP. Slow disease progression correlated with sine pigmento RP, absence of high myopia, and mutations in RPGR exons 1 to 14.

Clinical and Genetic Analysis of a European Cohort with Pericentral Retinitis Pigmentosa.

Retinitis pigmentosa (RP) is a clinically heterogenous disease that comprises a wide range of phenotypic and genetic subtypes. Pericentral RP is an atypical form of RP characterized by bone-spicule pigmentation and/or atrophy confined in the near mid-periphery of the retina. In contrast to classic RP, the far periphery is better preserved in pericentral RP. The aim of this study was to perform the first detailed clinical and genetic analysis of a cohort of European subjects with pericentral RP to determine the phenotypic features and the genetic bases of the disease. A total of 54 subjects from 48 independent families with pericentral RP, non-syndromic and syndromic, were evaluated through a full ophthalmological examination and underwent clinical exome or retinopathy gene panel sequencing. Disease-causative variants were identified in 22 of the 35 families (63%) in 10 different genes, four of which are also responsible for syndromic RP. Thirteen of the 34 likely pathogenic variants were novel. Intra-familiar variability was also observed. The current study confirms the mild phenotype of pericentral RP and extends the spectrum of genes associated with this condition.

Retinal dystrophy in an individual carrying a de novo missense variant of SMARCA4.

BACKGROUND: Coffin-Siris syndrome (CSS) is characterized by intellectual disability, dysmorphic facial features, growth deficiency, microcephaly, and abnormalities of the fifth fingers/toes. CSS is caused by mutations in several genes of the BRG1-associated factor pathway including SMARCA4. METHODS: Whole-exome sequencing was performed on a 14-year-old female individual who presented with mild intellectual disability and dysmorphic features, tooth abnormalities, and short stature. She had brachydactyly but no aplasia or hypoplasia of the distal phalanx or nail of the fifth digit. She was also found to have retinal dystrophy that has not been previously reported in CSS. RESULTS: The individual presented herein was found to harbor a previously unreported de novo variant in SMARCA4. CONCLUSION: This case expands the phenotypic spectrum of CSS manifestations.

A child with Myhre syndrome presenting with corectopia and tetralogy of Fallot.

Myhre syndrome is a rare autosomal dominant disorder caused by a narrow spectrum of missense mutations in the SMAD4 gene. Typical features of this disorder are distinctive facial appearance, deafness, intellectual disability, cardiovascular abnormalities, short stature, short hands and feet, compact build, joint stiffness, and skeletal anomalies. The clinical features generally appear during childhood and become more evident in older patients. Therefore, the diagnosis of this syndrome in the first years of life is challenging. We report a 2-year-old girl diagnosed with Myhre syndrome by whole exome sequencing (WES) that revealed the recurrent p.Ile500Val mutation in the SMAD4 gene. Our patient presented with growth deficiency, dysmorphic features, tetralogy of Fallot, and corectopia (also known as ectopia pupillae). The girl we described is the youngest patient with Myhre syndrome. Moreover, corectopia and tetralogy of Fallot have not been previously reported in this disorder.

Prevalence of macular abnormalities assessed by optical coherence tomography in patients with Usher syndrome.

BACKGROUND: To investigate the prevalence of macular abnormalities in patients affected by Usher syndrome (USH), by comparing the clinical findings between two types (i.e., USH1 and USH2). MATERIAL AND METHODS: A retrospective study was performed by reviewing optical coherence tomography (OCT) in 134 USH patients to determine the presence of macular abnormalities, including cystoid macular edema (CME), epiretinal membrane (ERM), vitreo-macular traction syndrome (VMT), and macular hole (MH). RESULTS: Macular abnormalities were observed in 126/268 (47.0%) examined eyes. The most frequent abnormality was ERM observed in 51 eyes (19%), followed by CME observed in 42 eyes (15.7%). Moreover, CME was significantly (p < 0.05) associated with younger age (CME: 30.1 ± 11.1 years; without CME: 36.9 ± 14.9 years), whereas VMT and full thickness MH were associated with older age (p < 0.05). Moreover, a significantly (p < 0.05) decreased best-corrected visual acuity was associated with MH compared to eyes without MH. Finally, CME was more frequent in USH1 compared to USH2. CONCLUSION: Our study, for the first time in the literature, showed the distribution of all macular abnormalities assessed by SD-OCT in a large USH cohort, comparing USH1 and USH2 patients. We observed that ocular abnormalities are highly prevalent in USH patients compared to general population, with ERM and CME being the most common alterations. Based on these findings, OCT screening in USH patients is recommended for early detection of macular changes and early treatment.

Clinical and Genetic Evaluation of a Cohort of Pediatric Patients with Severe Inherited Retinal Dystrophies.

We performed a clinical and genetic characterization of a pediatric cohort of patients with inherited retinal dystrophy (IRD) to identify the most suitable cases for gene therapy. The cohort comprised 43 patients, aged between 2 and 18 years, with severe isolated IRD at the time of presentation. The ophthalmological characterization also included assessment of the photoreceptor layer integrity in the macular region (ellipsoid zone (EZ) band). In parallel, we carried out a targeted, next-generation sequencing (NGS)-based analysis using a panel that covers over 150 genes with either an established or a candidate role in IRD pathogenesis. Based on the ophthalmological assessment, the cohort was composed of 24 Leber congenital amaurosis, 14 early onset retinitis pigmentosa, and 5 achromatopsia patients. We identified causative mutations in 58.1% of the cases. We also found novel genotype-phenotype correlations in patients harboring mutations in the CEP290 and CNGB3 genes. The EZ band was detectable in 40% of the analyzed cases, also in patients with genotypes usually associated with severe clinical manifestations. This study provides the first detailed clinical-genetic assessment of severe IRDs with infantile onset and lays the foundation of a standardized protocol for the selection of patients that are more likely to benefit from gene replacement therapeutic approaches.

Chlamydia trachomatis induces an upregulation of molecular biomarkers podoplanin, Wilms' tumour gene 1, osteopontin and inflammatory cytokines in human mesothelial cells.

Chlamydia trachomatis is the most prevalent infection of the genital tract in women worldwide. C. trachomatis has a tendency to cause persistent infection and induce a state of chronic inflammation, which has been reported to play a role in carcinogenesis. We report that persistent C. trachomatis infection increases the expression of inflammatory tumour cytokines and upregulates molecular biomarkers such as podoplanin, Wilms' tumour gene 1 and osteopontin in primary cultures of mesothelial cells (Mes1) and human mesothelioma cells (NCI). Infection experiments showed that Mes1 and NCI supported the growth of C. trachomatisin vitro, and at an m.o.i. of 4, the inclusion-forming units/cell showed many intracellular inclusion bodies after 3 days of infection. However, after 7 days of incubation, increased proliferative and invasive activity was also observed in Mes1 cells, which was more evident after 14 days of incubation. ELISA analysis revealed an increase in vascular endothelial growth factor, IL-6, IL-8, and TNF-α release in Mes1 cells infected for a longer period (14 days). Finally, real-time PCR analysis revealed a strong induction of podoplanin, Wilms' tumour gene 1 and osteopontin gene expression in infected Mes1 cells. The aim of the present study was to investigate the inflammatory response elicited by C. trachomatis persistent infection and the role played by inflammation in cell proliferation, secretion of proinflammatory cytokines and molecular biomarkers of cancer. The results of this study suggest that increased molecular biomarkers of cancer by persistent inflammation from C. trachomatis infection might support cellular transformation, thus increasing the risk of cancer.

Mutations in the PCYT1A gene are responsible for isolated forms of retinal dystrophy.

Mutations in the PCYT1A gene have been recently linked to two different phenotypes: one characterized by spondylometaphyseal dysplasia and cone-rod dystrophy (SMD-CRD) and the other by congenital lipodystrophy, severe fatty liver disease, and reduced HDL cholesterol without any retinal or skeletal involvement. Here, we identified, by next generation sequencing, sequence variants affecting function in the PCYT1A gene in three young patients with isolated retinal dystrophy from two different Italian families. A thorough clinical evaluation of the patients, with whole skeleton X-ray, metabolic assessment and liver ultrasound failed to reveal signs of skeletal dysplasia, metabolic and hepatic alterations. This is the first report showing that the PCYT1A gene can be responsible for isolated forms of retinal dystrophy, particularly without any skeletal involvement, thus further expanding the phenotypic spectrum induced by mutations in this gene.

Infiltrating giant cell tumor in a case of Paget's disease of bone.

Giant cell tumor (GCT) of the bone, also called osteoclastoma, is a rare complication of Paget's bone disease. We report a patient from Southern Italy who developed a GCT infiltrating the neighboring tissues. The natural history and the therapeutic outcomes of this unique complication of Paget's bone disease are presented.