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To determine the incidence of rhegmatogenous retinal detachments (RRDs) and proliferative vitreoretinopathies (PVRs) and their distribution by age and sex in hospitalized patients in Japan. Retrospective nationwide observational study. Information on the number of inpatients primarily diagnosed with RRD or PVR and their age and sex were collected from the Diagnosis Procedure Combination (DPC) database for 2014 and 2015. The incidence was determined using the Japanese population report published by the Public Management Ministry’s Statistics Bureau. The incidence of RRD in these hospitalized patients was 10.9/100,000, with 15.0/100,000 in men and 7.1/100,000 in women, and that of PVR was 2.1/100,000, with 2.9/100,000 in men and 1.3/100,000 in women. The incidence in men was twice that in women for both RRD and PVR. The distribution of RRD by age was monophasic, with a peak at 50 years for both sexes, and that of PVR was at peak in the 60 s for men and in the 70 s for women. PVR was more common than RRD in children aged younger than 10 years, but the incidence of RRD was higher in the other age groups. A study of the DPC database can provide useful information on the incidences of RRD and PVR in hospitalized patients in Japan.

Objective To determine the efficacy and safety of fremanezumab administration in Japanese and Korean patients with chronic migraine (CM). Background Available preventive treatments for CM are limited by various efficacy and safety issues. Fremanezumab, a monoclonal antibody that targets the calcitonin gene‐related peptide pathway involved in migraine pathogenesis, has been shown to be effective and well tolerated in large‐scale, international Phase 3 trials. Methods Randomized, placebo‐controlled trial of patients with CM who received subcutaneous fremanezumab monthly (675 mg at baseline and 225 mg at weeks 4 and 8), fremanezumab quarterly (675 mg at baseline and placebo at weeks 4 and 8), or matching placebo. Primary endpoint was the mean change from baseline in the monthly (28‐day) average number of headache days of at least moderate severity during the 12 weeks after the first dose. Results Among 571 patients randomized (safety set, n = 569; full analysis set, n = 566), the least‐squares mean (±standard error [SE]) reduction in the average number of headache days of at least moderate severity per month during 12 weeks was significantly greater with fremanezumab monthly (–4.1 ± 0.4) and fremanezumab quarterly (–4.1 ± 0.4) than with placebo (–2.4 ± 0.4). The difference from the placebo group in the mean change (95% confidence interval [CI]) was −1.7 days (−2.54, −0.80) for the fremanezumab monthly group and −1.7 days (−2.55, −0.82) for the fremanezumab quarterly group (p

Objective To evaluate the efficacy and safety of two dosing regimens of fremanezumab in Japanese and Korean patients with episodic migraine. Background Episodic migraine, which accounts for more than 90% of migraine cases, is inadequately addressed by widely available preventive therapies. Fremanezumab, a monoclonal antibody that selectively targets the trigeminal sensory neuropeptide calcitonin gene‐related peptide involved in migraine pathogenesis, has demonstrated efficacy in international Phase 3 trials of patients with both chronic and episodic migraine. Methods This Phase 3 randomized, placebo‐controlled trial randomly assigned patients with episodic migraine to receive subcutaneous fremanezumab monthly (225 mg at baseline, week 4, and week 8), fremanezumab quarterly (675 mg at baseline and placebo at weeks 4 and 8), or matching placebo. The primary endpoint was the mean change from baseline in the monthly average number of migraine days during the 12‐week treatment period after the first dose. Results Of 357 patients enrolled (safety set, n = 356; full analysis set, n = 354), the least‐squares mean (±standard error) reductions in the average number of migraine days per month during 12 weeks were significantly greater with fremanezumab monthly (−4.0 ± 0.4, n = 121) and fremanezumab quarterly (−4.0 ± 0.4, n = 117) than with placebo (−1.0 ± 0.4, n = 116; p

To characterize the clinical and genetic features of a Japanese male patient with foveal hypoplasia caused by a homozygous single nucleotide duplication in the SLC38A8 gene. We performed a comprehensive ophthalmic examination including full-field electroretinography (FF-ERG) and pattern-reversal visual evoked potentials (PR-VEPs). Whole-exome sequencing (WES) was performed to identify the disease-causing variant; Sanger sequencing was used for confirmation. In the WES analysis, a homozygous single nucleotide duplication (c.995dupG; p.Trp333MetfsTer35) was identified in SLC38A8 of the patient. His unaffected mother carried the variant heterozygously. The patient exhibited hyperopia, congenital nystagmus, low visual acuity, and grade 4 foveal hypoplasia. Slit-lamp examination revealed mild posterior embryotoxon and goniodysgenesis. Fundus examination revealed the absence of foveal hyperpigmentation and foveal avascularity, but there were no retinal degenerative lesions. In the FF-ERG, the amplitudes of rod ERG, standard-flash, and bright-flash ERG were within the normal range; cone-mediated responses also showed nearly normal amplitudes. The PR-VEP findings revealed delayed P100 latencies and decreased amplitudes of the P100 components, but no chiasmal misrouting. This report is the first report on the clinical and genetic characteristics of SLC38A8-associated foveal hypoplasia in the Japanese population. This is also the first report of normal rod- and cone-mediated responses in a patient with this disorder.

The aim of this study was to evaluate the safety and effectiveness of rotigotine under daily clinical practice in Parkinson's disease patients.The study was a prospective, non-interventional, observational study targeting patients who were treated with rotigotine for the first time, with a 1-year follow-up period from September 2013 to August 2016.There were 603 patients in the safety population and 599 patients in the effectiveness population. The mean age was 71.6 years, and the age group of ≥65 and ≥80 years accounted for 80% and 18.6% of all patients, respectively. The frequency of adverse drug reaction (ADR) was 34.3%, and common ADRs were application site reaction (20.2%), typical for transdermal patches. However, the majority of patients recovered or was recovering from these ADRs and were non-serious. Although ADRs related to non-motor symptoms of Parkinson's disease were observed, most of them were non-serious. Total scores of the Unified Parkinson's Disease Rating Scale Part III (UPDRS-III) (ON-time) significantly decreased from baseline in the effectiveness population. In the analysis of overall improvement in 12 months of post-treatment, ≥70% of patients achieved mild or greater improvement. The safety profiles and improvements in the UPDRS-III score were similar in both the ≥80 years of age group and younger age group.There were no new or notable safety concerns observed, and the effectiveness of rotigotine was suggested in daily clinical practice.

Supplemental Digital Content is Available in the Text. We studied 46 eyes with Stickler syndrome using ultra-widefield fundus autofluorescence images. Abnormal autofluorescence lesions were found in 81% of the eyes that were associated with age-related alteration and visual field defects., Purpose: To determine the characteristics of fundus autofluorescence (FAF) images and visual functions in eyes with Stickler syndrome using ultra-widefield FAF images. Methods: Forty-six eyes of 26 patients with mutations in the COL2A1 gene underwent ultra-widefield FAF imaging. The eyes were categorized into three types; no signs of abnormal AF, predominantly hyperfluorescent AF (hyper-AF), and predominantly hypofluorescent AF (hypo-AF). Goldmann perimetry was performed on 34 eyes, and line-scan images of the abnormal AF lesions were obtained by swept-source optical coherence tomography in 4 eyes. Results: Abnormal AF lesions were found in 37 eyes of 21 (80.7%) of the 26 patients. Hyper-AF was found in 15 eyes and hypo-AF was found in 22 eyes. The FAF changes corresponded with the funduscopically observed radial paravascular retinal degeneration. The average age at the examination was significantly younger in patients who had eyes with hyper-AF or no abnormal AF than in those with hypo-AF (12.8 vs. 28.4 years; P = 0.009). Abnormal AF-associated visual field defects were found in 5/10 (50%) eyes with hyper-AF and 17/18 (94%) eyes with hypo-AF. Hyper-AF changes tended to appear before retinal changes were detectable by fluorescein angiography. An absence of the ellipsoid zone and the outer nuclear layer and a thinning of the overall retinal thickness were found corresponding to the hypo-AF lesions in the swept source optical coherence tomography images. Conclusion: Abnormal FAF is characteristic of eyes with Stickler syndrome. Age-related alterations of the FAF was associated with visual field defects and disruption of the photoreceptors and retinal pigment epithelial cells.

Background:Limited epidemiological data are available for headache disorders in Japan, and no recent studies have reported the impact of several primary headache disorders in Japan. This study aimed to report the up-to-date epidemiological data and impact of primary headaches on daily activities as well as the use of medical care, clinical features, and pain severity/activity impairment using nationwide data in Japan.Methods:We used anonymized online survey data coupled with medical claims data, from individuals aged 19-74 years old, that were provided by DeSC Healthcare Inc. The outcomes included the prevalence of migraine, tension-type headache, cluster headache, and other headache types stratified by age and sex, use of medical care, clinical features, medication use, and severity of pain/activity impairment. All outcomes were examined separately for each headache type. This is the second paper reported concurrently with this research.Results:The study population comprised 691/1,441/21/5,208 individuals with migraine/tension-type headache/cluster headache/other headache types, respectively. The prevalence of migraine and tension-type headache was higher in women than in men but was similar for cluster headache (male vs. female, 1.7% vs. 7.4%, 5.3% vs. 10.8%, and 0.1% vs. 0.1%, respectively). The percentage of individuals with migraine, tension-type headache, cluster headache who had not seen a doctor was 81.0%, 92.0%, 57.1%, respectively. The common headache triggers were fatigue in migraine and tension-type headache, and weather-related phenomena and turning of the seasons in migraine. Common activities refrained from or reduced by headaches were “operating a computer or smartphone”, “drinking alcohol”, and “going to crowded places” in all three headache types and housework-related activities in women. Among individuals taking medicines, 16.8%, 15.8%, 47.6% with migraine, tension-type headache, and cluster headache reported moderate to severe pain, respectively, and 12.6%, 7.7%, 19.0% reported moderate to severe disability, respectively.Conclusions:This study found various triggers of headache attacks, and daily activities refrained from or reduced by headaches. Additionally, this study suggested that the disease burden in people possibly experiencing tension-type headaches, many of whom had not seen a doctor. The study findings are of clinical value for the diagnosis and treatment of primary headaches.

BackgroundMigraine is a chronic disease characterized by episodic headache attacks. No recent studies have, however been conducted on the epidemiology of migraine or the treatment landscape in Japan. This study was conducted as a fact-finding survey using medical claims receipt data and an online survey on migraine and headaches, conducted among members of health insurance associations with the objective of gaining an understanding of migraine prevalence and the treatment status in Japan.MethodsThe study methodology utilized a unique approach of combined data sources. The data sources used in this study are medical claims receipt data and online survey data provided by DeSC Healthcare Inc (DeSC). The primary outcomes (from survey responses) were: the overall number and proportion of migraine patients; and the overall prevalence of migraine, stratified by age and sex. The secondary outcomes (from survey responses) were use of medical care; and clinical features/headache symptoms. The analysis population included all individuals who had response data for surveys conducted by DeSC. The online survey data and medical claims receipt data were summarized. ResultsThe data population comprised 21,480 individuals. On the basis of the survey results, including probable cases, the overall prevalence of migraine was 3.2%. The highest prevalence of migraine was observed in patients aged 30-39 years. The prevalence of migraine in women was 4.4 times higher than in men. The percentage of migraine patients who had not been seen by a doctor was 81.0%. More than 80% of patients were taking over-the-counter drugs and 4.8% took prescription medicines only. Approximately 52.9% of patients considered that the intensity of pain symptoms was severe. Moreover, the majority of patients (72.9%) considered that the impairment of daily life activities was of moderate or severe degree. ConclusionsIn Japan, the percentage of people with migraine who did not receive medical attention is as high as 80%. Additionally, the majority of patients tend to endure symptoms and continue with everyday activities. With innovative treatment approaches becoming available it is necessary to disseminate information that migraine is not a simple headache but an illness that requires medical treatment and consultation.

To investigate late vitreoretinal complications and visual outcomes in patients with regressed retinopathy of prematurity (ROP) with or without prior treatment.International, multicenter, noncomparative retrospective case series.We analyzed 264 eyes of 238 patients from 13 centers worldwide who developed vitreoretinal complications (retinal detachment [RD], vitreous hemorrhage [VH], or retinal break) ≥ 2 years after resolution of acute ROP.Each participant was assigned to 1 of 3 groups (the RD, VH, and retinal break groups) according to their primary diagnosis. The average age at presentation, visual acuities, refractive error, axial length, gestational age, birth weight, acute ROP classification, prior treatments for acute ROP, postoperative visual acuity (VA), and concomitant eye conditions in the 3 groups were documented and compared.Clinical features and visual outcomes of late vitreoretinal complications in patients with regressed ROP.A total of 264 eyes of 238 patients were included. The prior acute ROP status was comparable among the 3 groups, except that the VH group had a higher proportion of patients with type 1 ROP (P = 0.03) and prior treatment (P0.001) than the other groups. The average age at presentation was earlier in the RD (20.3 ± 15.5 years) and VH (21.4 ± 18.9 years) groups than in the retinal break group (31.9 ± 18.2 years; P0.001). The retinal break group had the best presenting best-corrected VA, followed by the RD and VH groups (P0.001). Surgical intervention improved VA in both the RD and VH groups (both P0.05). The overall trend of VA was the most favorable in the retinal break group, followed by that in the VH and RD groups. Cicatricial changes in the fellow retina were observed in90% of patients with unilateral involvement.Infants with acute ROP remain at a high risk of vision-threatening complications throughout childhood and adulthood. Continual follow-up of patients with ROP is important. When severe complications, such as RD or VH, are detected, timely surgical intervention is necessary to ensure favorable visual outcomes in these patients.

To report the ocular findings in 3 patients with a mutation in the ATOH7 gene.The clinical findings were collected from the medical records including those for magnetic resonance imaging (MRI). Genetic testing of the ATOH7 gene was performed.Three patients of two families who had poor vision since infancy were studied.The 3 patients had varying degrees of intraocular vascular proliferation associated with advanced retinal detachments as falciform retinal folds or total retinal detachments. This state is referred to as congenital retinal nonattachment. One eye of a sibling had fluorescein angiographic findings of excessive branching of the retinal vessels and fluorescent dye leakage that were consistent with those of familial exudative vitreoretinopathy (FEVR). Bilateral hypoplasia of the optic nerve was found in all three patients by MRI. Genetic analysis showed a known in-frame deletion of the ATOH7 gene in all three patients.This is the first report of a patient with a mutation in the ATOH7 gene that had typical vascular patterns of FEVR in the peripheral retina. The ocular features associated with mutations in the ATOH7 gene overlap those with FEVR at both the early and advanced stages.

To present the clinical characteristics, surgical outcomes, and surgical complications of patients with congenital X-linked retinoschisis who underwent vitrectomy for bullous schisis cavity hanging over or threatening the macula.Nine patients with congenital X-linked retinoschisis (12 eyes) who underwent vitrectomy at three tertiary hospitals and completed ≥3 years of postoperative follow-up were retrospectively investigated. Data were collected from patients' charts, including age at vitrectomy, surgical procedures, and postoperative complications.The age at vitrectomy ranged 4 months to 103 months (median: 14 months). Inner wall retinectomy was performed during the initial vitrectomy in eight eyes. Among the eight eyes that initially underwent inner wall retinectomy, one (12.5%) required subsequent retinal surgery for postoperative complication. Furthermore, four eyes did not undergo initial inner wall retinectomy but required subsequent retinal surgeries for postoperative complications. Three of five eyes (60.0%) treated with silicone oil tamponade and two of seven eyes (28.6%) that were not treated with silicone oil tamponade during the initial vitrectomy required subsequent retinal surgeries for postoperative complications. All eyes maintained a clear central visual axis at the last examination.Inner wall retinectomy seems beneficial in achieving a clear visual axis in eyes with bullous schisis cavity hanging over or threatening the macula in patients with congenital X-linked retinoschisis.

Peripherin-2 (PRPH2) is one of the causative genes of inherited retinal dystrophy. While the gene is relatively common in Caucasians, reports from Asian ethnicities are limited. In the present study, we report 40 Japanese patients from 30 families with PRPH2-associated retinal dystrophy. We identified 17 distinct pathogenic or likely pathogenic variants using next-generation sequencing. Variants p.R142W and p.V200E were relatively common in the cohort. The age of onset was generally in the 40’s; however, some patients had earlier onset (age: 5 years). Visual acuity of the patients ranged from hand motion to 1.5 (Snellen equivalent 20/13). The patients showed variable phenotypes such as retinitis pigmentosa, cone-rod dystrophy, and macular dystrophy. Additionally, intrafamilial phenotypic variability was observed. Choroidal neovascularization was observed in three eyes of two patients with retinitis pigmentosa. The results demonstrate the genotypic and phenotypic variations of the disease in the Asian cohort., Genes, 12(11), art. no. 1817; 2021

Peripherin-2 (PRPH2) is one of the causative genes of inherited retinal dystrophy. While the gene is relatively common in Caucasians, reports from Asian ethnicities are limited. In the present study, we report 40 Japanese patients from 30 families with PRPH2-associated retinal dystrophy. We identified 17 distinct pathogenic or likely pathogenic variants using next-generation sequencing. Variants p.R142W and p.V200E were relatively common in the cohort. The age of onset was generally in the 40’s; however, some patients had earlier onset (age: 5 years). Visual acuity of the patients ranged from hand motion to 1.5 (Snellen equivalent 20/13). The patients showed variable phenotypes such as retinitis pigmentosa, cone-rod dystrophy, and macular dystrophy. Additionally, intrafamilial phenotypic variability was observed. Choroidal neovascularization was observed in three eyes of two patients with retinitis pigmentosa. The results demonstrate the genotypic and phenotypic variations of the disease in the Asian cohort.

BNT162b2, a nucleoside-modified mRNA vaccine for SARS-CoV-2 spike glycoprotein (S), provides approximately 95% efficacy for preventing COVID-19. However, it remains unclear how effectively memory CD8+ T cells are generated and which genetic and environmental factors affect the generation and function of memory CD8+ T cells elicited by this vaccine. Here, we investigated the frequency and functions of memory CD8+ T cells 3 weeks after the second vaccination in the Japanese population. Using a peptide-MHC pentamer, we detected an increased number of memory CD8+ T cells together with increased serum anti-S protein antibody in females compared with that in males, but the frequency of pentamer-positive cells was not positively correlated with antibody titers. Memory precursor effector cells (KLRG1-CD127+) among both CD8+ cells and pentamer+ cells and effector cells (CD38-HLA-DR+) among pentamer+ cells were more abundant in females than in males. Upon S protein-mediated stimulation of T cells, the intensity of CD107a and granzyme B expression was increased in females compared with that in males, indicating stronger memory CD8+ T cell responses in females than in males. Our studies showed that the BNT162b2 vaccine elicits increased memory CD8+ T cell proliferation and secondary CTL responses in females compared with those in males in the Japanese population. These findings provide an important basis for the distinct sex difference in cellular immune responses to mRNA vaccination and suggest that memory precursor effector cells can be one of markers to evaluate and boost cellular immunity induced by BNT162b2.

Hiroyuki Kondo, Takafumi Matsumura, Mari Kaneko, Kenichi Inoue, Hidetaka Kosako, Masahito Ikawa, Yousuke Takahama, Izumi Ohigashi, PITHD1 is a proteasome-interacting protein essential for male fertilization, Journal of Biological Chemistry, Volume 295, Issue 6, 2020, Pages 1658-1672, ISSN 0021-9258, https://doi.org/10.1074/jbc.RA119.011144., The proteasome is a protein-degrading molecular complex that is necessary for protein homeostasis and various biological functions, including cell cycle regulation, signal transduction, and immune response. Proteasome activity is finely regulated by a variety of proteasome-interacting molecules. PITHD1 is a recently described molecule that has a domain putatively capable of interacting with the proteasome. However, it is unknown whether PITHD1 can actually bind to proteasomes and what it does in vivo. Here we report that PITHD1 is detected specifically in the spermatids in the testis and the cortical thymic epithelium in the thymus. Interestingly, PITHD1 associates with immunoproteasomes in the testis, but not with thymoproteasomes in the thymus. Mice deficient in PITHD1 exhibit severe male infertility accompanied with morphological abnormalities and impaired motility of spermatozoa. Furthermore, PITHD1 deficiency reduces proteasome activity in the testis and alters the amount of proteins that are important for fertilization capability by the sperm. However, the PITHD1-deficient mice demonstrate no detectable defects in the thymus, including T cell development. Collectively, our results identifyPITHD1as a proteasome- interacting protein that plays a nonredundant role in the male reproductive system.

To expand Internet of Things application ranges, ultralow active energy operations are essential in edge devices. Especially, read energy reduction in embedded Flash (eFlash) memory is strongly required to enable real-time sensing with limited energy generated by energy harvesting (EH). In this letter, 1.5-MB and 256-KB 2T-MONOS eFlash macros are developed with 65-nm silicon-on-thin-box (SOTB) technology, adopting low-energy sense amplifier and data transmission circuit techniques which enhance intrinsic advantages of SOTB devices. These macros achieve read energy of 0.15-pJ/bit with 80-MHz random read access capability, which is low enough to utilize EH technologies as energy sources.

This letter presents an embedded flash (eFlash) system based on 28-nm split-gate MONOS (SG-MONOS) with high- ${k}$ metal gate CMOS process technology for automotive applications. It contains the world’s largest 24-MB memory capacity (4-MB code flash macro (CF) $\times6$ ) and achieves 240-MHz random read access at Tj from −40 °C to 170 °C, and read throughput reaches 46 GB/s by reading 6 CFs in parallel. The peak current consumption during over-the-air software update (OTA) is reduced by 55% in low-noise program mode. A high-speed program mode for factory program and test achieves 6.5-MB/s program throughput by programming 2 CFs in parallel. In OTA, the eFlash system realizes ~1 ms software switching and robustness against unintentional OTA termination.

SUMMARY The thymic function to produce self-protective and self-tolerant T cells is chiefly mediated by cortical thymic epithelial cells (cTECs) and medullary TECs (mTECs). Recent studies including single-cell transcriptomic analyses have highlighted a rich diversity in functional mTEC subpopulations. Because of their limited cellularity, however, the biochemical characterization of TECs, including the proteomic profiling of cTECs and mTECs, has remained unestablished. Utilizing genetically modified mice that carry enlarged but functional thymuses, here we show a combination of proteomic and transcriptomic profiles for cTECs and mTECs, which identified signature molecules that characterize a developmental and functional contrast between cTECs and mTECs. Our results reveal a highly specific impact of the thymoproteasome on proteasome subunit composition in cTECs and provide an integrated trans-omics platform for further exploration of thymus biology., In Brief Ohigashi et al. show that the use of cyclin D1-transgenic mice allows quantitative proteomic analysis of cortical and medullary thymic epithelial cells (TECs). Results provide a trans-omics platform for further exploration of TEC biology and reveal the specific impact of the thymoproteasome on proteasome subunit composition in cortical TECs., Graphical Abstract

Background: Revesz syndrome is a rare type of the dyskeratosis congenita spectrum disorder that is characterized by nail dystrophy, oral leukoplakia, and abnormal skin pigmentation. The retinal features are similar to those of exudative retinopathy with avascular areas of the peripheral retina. There are only a few publications describing patients with Revesz syndrome who underwent ocular treatments for the retinal complications. We report a Case of Revesz syndrome with bilateral retinal detachments that were successfully reattached by pars plana vitrectomy. Observations: A 3-year-old Japanese girl with Revesz Syndrome had progressive vitreal hemorrhages and tractional retinal detachments in both eyes. She underwent pars plana vitrectomy with lensectomy on both eyes. A retinal attachment with vision improvement was achieved by a single surgery for the right eye and after repeated surgeries for the left eye. Postoperative electroretinographic (ERG) examinations of the right eye showed a negative type ERG with the b-wave/a-wave ratio

This study investigated the surgical outcomes of Coats disease and the role of external drainage (XD) of subretinal fluid (SRF). The study is a multicenter retrospective interventional case series of 26 consecutive eyes of 26 patients who underwent surgeries for advanced Coats disease with retinal detachment. Main outcomes measured were: 1) comparison of complete SRF resolution with or without XD, and 2) variables that were associated with functional postoperative best-corrected visual acuity (BCVA) defined as BCVA of 0.1 or better, 3) intraocular vascular endothelial growth factor (VEGF) levels. Complete SRF resolution was achieved in all 14 eyes in which XD had been performed and in 75% of 12 eyes in which XD had not been performed (P = .03). Multivariable logistic regression analysis revealed that initial BCVA was the only variable associated with functional postoperative BCVA (odds ratio 3.24, 95% CI 0.93–11.33; P = .04). Markedly elevated VEGF levels were noted in the SRF compared with those in the vitreous humor (49,760 ± 52,990 vs. 707 ± 611 pg/mL, P = .03). XD seems to provide better anatomical success than without XD in the treatment of advanced Coats disease as XD could effectively eliminate substantial amount of VEGF in the SRF.

Background: Little is known about genotype–phenotype correlations of RP1-associated retinal dystrophies in the Japanese population. We aimed to investigate the genetic spectrum of RP1 variants and provide a detailed description of the clinical findings in Japanese patients. Methods: In total, 607 patients with inherited retinal diseases were examined using whole-exome/whole-genome sequencing (WES/WGS). PCR-based screening for an Alu element insertion (c.4052_4053ins328/p.Tyr1352AlafsTer9) was performed in 18 patients with autosomal-recessive (AR)-retinitis pigmentosa (RP) or AR-cone dystrophy (COD)/cone-rod dystrophy (CORD), including seven patients with heterozygous RP1 variants identified by WES/WGS analysis, and 11 early onset AR-RP patients, in whom no pathogenic variant was identified. We clinically examined 25 patients (23 families) with pathogenic RP1 variants, including five patients (five families) with autosomal-dominant (AD)-RP, 13 patients (11 families) with AR-RP, and seven patients (seven families) with AR-COD/CORD. Results: We identified 18 pathogenic RP1 variants, including seven novel variants. Interestingly, the Alu element insertion was the most frequent variant (32.0%, 16/50 alleles). The clinical findings revealed that the age at onset and disease progression occurred significantly earlier and faster in AR-RP patients compared to AD-RP or AR-COD/CORD patients. Conclusions: Our results suggest a genotype–phenotype correlation between variant types/locations and phenotypes (AD-RP, AR-RP, and AR-COD/CORD), and the Alu element insertion was the most major variant in Japanese patients with RP1-associated retinal dystrophies.

Background: Little is known about genotype–phenotype correlations of RP1-associated retinal dystrophies in the Japanese population. We aimed to investigate the genetic spectrum of RP1 variants and provide a detailed description of the clinical findings in Japanese patients. Methods: In total, 607 patients with inherited retinal diseases were examined using whole-exome/whole-genome sequencing (WES/WGS). PCR-based screening for an Alu element insertion (c.4052_4053ins328/p.Tyr1352AlafsTer9) was performed in 18 patients with autosomal-recessive (AR)-retinitis pigmentosa (RP) or AR-cone dystrophy (COD)/cone-rod dystrophy (CORD), including seven patients with heterozygous RP1 variants identified by WES/WGS analysis, and 11 early onset AR-RP patients, in whom no pathogenic variant was identified. We clinically examined 25 patients (23 families) with pathogenic RP1 variants, including five patients (five families) with autosomal-dominant (AD)-RP, 13 patients (11 families) with AR-RP, and seven patients (seven families) with AR-COD/CORD. Results: We identified 18 pathogenic RP1 variants, including seven novel variants. Interestingly, the Alu element insertion was the most frequent variant (32.0%, 16/50 alleles). The clinical findings revealed that the age at onset and disease progression occurred significantly earlier and faster in AR-RP patients compared to AD-RP or AR-COD/CORD patients. Conclusions: Our results suggest a genotype–phenotype correlation between variant types/locations and phenotypes (AD-RP, AR-RP, and AR-COD/CORD), and the Alu element insertion was the most major variant in Japanese patients with RP1-associated retinal dystrophies.