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OBJECTIVE To investigate CYP4V2 gene variants and ocular clinical characteristics of Bietti corneoretinal crystalline dystrophy in China so as to provide more references for genotype and phenotype of BCD. METHODS Sixteen Chinese probands were recruited in Beijing Tongren Hospital in a retrospective study. All patients underwent CYP4V2 gene detection and ophthalmic clinical examinations. RESULTS CYP4V2 gene variants were detected in all patients. Eight variants were identified, and the most common one was c.802-8_810del17bpinsGC. Onset age of BCD was from 12 to 44 years, and the first symptoms mostly were decreased visual acuity or night blindness. Corneal crystalline depositions were observed in all patients and were found not only in epithelium and superficial stroma near the limbus but also in corneal endothelium. OCT showed atrophy of RPE in all patients, outer retinal tubulation in ten patients, macular edema in four patients, macular hole in three patients with one accompanied with retinal detachment, and choroidal neovascularization in one patient. CONCLUSION CYP4V2 gene variants were detected in all patients consistent with the genetic locus homogeneity of BCD, and c.802-8_810del17bpinsGC was the most common mutation. Corneal crystalline depositions were observed in all patients, which may be features of BCD and helpful for the diagnosis of BCD patients, especially those in the advanced stage without typical fundus crystalline depositions or without gene detection. However, considerable phenotypic variability was detected. Corneal crystalline deposits were observed not only in epithelium and superficial stroma but also in endothelium, which has not been reported before. This may provide further evidence for the variable phenotypic expression between affected individuals.

Importance Inherited retinal dystrophies (IRDs) are a group of monogenic diseases, one of the leading causes of blindness. Background Introducing a comprehensive genetic testing strategy by combining single gene Sanger sequencing, next-generation sequencing (NGS) including whole exome sequencing (WES), and a specific hereditary eye disease enrichment panel (HEDEP) sequencing, to identify the disease-causing variants of 800 Chinese probands affected with non-syndromic IRDs. Design Retrospective analysis. Participants Eight hundred Chinese non-syndromic IRDs probands and their families. Methods A total of 149 patients were subjected to Sanger sequencing. Of the 651 patients subjected to NGS, 86 patients underwent WES and 565 underwent HEDEP. Patients that likely carried copy number variations (CNVs) detected by HEDEP were further validated by multiplex ligation-dependent probe amplification (MLPA) or quantitative fluorescence PCR (QF-PCR). Main outcome measures The diagnostic rate. Results (Likely) pathogenic variants were determined in 481 cases (60.13% detection rate). The detection rates of single gene Sanger sequencing, WES and HEDEP were 86.58%, 31.40% and 56.99%, respectively. Approximately 11.64% of 481 cases carried autosomal dominant variants, 72.97% carried AR variants and 15.39% were found to be X-linked. CNVs were confirmed by MLPA or QF-PCR in 17 families. Fourteen genes that each caused disease in 1% or more of the cohort were detected, and these genes were collectively responsible for disease in almost one half (46.38%) of the families. Conclusions and relevance Sanger sequencing is ideal to detect pathogenic variants of clinical homogeneous diseases, whereas NGS is more appropriate for patients without an explicit clinical diagnosis.

To investigate complex and different phenotypes in seven Chinese patients diagnosed with Bardet–Biedl syndrome (BBS) and carrying pathogenic mutations. Seven unrelated BBS patients were enrolled. Their medical and ophthalmic histories were reviewed, and comprehensive clinical examinations, such as fundus photography, optical coherence tomography, and medical imaging, were performed. A specific hereditary eye disease enrichment panel based on exome-capture technology was used to collect and amplify the protein-coding regions of 441 targeted hereditary eye disease genes, followed by high-throughput sequencing using the Illumina HiSeq platform. All patients exhibited the primary clinical phenotype of BBS. Seven BBS mutations were found in five patients (BBS7 in two patients, BBS10 in two patients, BBS12 in one patient), for a detection rate of 71% (5/7). The ratio of novel to known BBS mutations was 5:2. This study showed the phenotypic and genotypic spectrum of BBS patients from China, and the findings underscore the importance of obtaining comprehensive clinical observations and molecular analyses for ciliopathies.

Background RP (retinitis pigmentosa) is a group of hereditary retinal degenerative diseases. XLRP is a relatively severe subtype of RP. Thus, it is necessary to identify genes and mutations in patients who present with X-linked retinitis pigmentosa. Methods Genomic DNA was extracted from peripheral blood. The coding regions and intron-exon boundaries of the retinitis pigmentosa GTPase regulator (RPGR) and RP2 genes were amplified by PCR and then sequenced directly. Ophthalmic examinations were performed to identify affected individuals from two families and to characterize the phenotype of the disease. Results Mutation screening demonstrated two novel nonsense mutations (c.1541C > G; p.S514X and c.2833G > T; p.E945X) in the RPGR gene. The clinical manifestation of family 1 with mutations in exon 13 was mild. Genotype-phenotype correlation analysis suggested that patients with mutations close to the downstream region of ORF15 in family 2 manifested an early loss of cone function. Family 2 carried a nonsense mutation in ORF15 that appeared to have a semi-dominant pattern of inheritance. All male patients and two female carriers in family 2 manifested pathological myopia (PM), indicating that there may be a distinctive X-linked genotype-phenotype correlation between RP and PM. Conclusions We identified two novel mutations of the RPGR gene, which broadens the spectrum of RPGR mutations and the phenotypic spectrum of the disease in Chinese families.

Objective We aimed to determine the location of neurotrophic receptors tropomyosin receptor kinase (Trk)B, TrkC, and ciliary neurotrophic factor receptor (CNTFR)α in the retina of retinal degeneration ( rd) mice and to explore the dynamic changes of B-cell lymphoma-2 (Bcl-2), Bcl-2-associated X-protein (Bax), and microtubule-associated protein light chain 3 (LC3) expression and ultrastructure in the retina of rd mice intravitreally injected with neurotrophic factors. Methods Rd mice aged 2 and 3 weeks post-natally (PN) received intravitreal injections of neurotrophic factors. Two weeks later, their retinas were harvested for the detection of Bax, Bcl-2, and LC3 mRNA and protein expression. Results TrkB and TrkC expression levels were lower at 3 weeks PN compared with 0, 1, and 2 weeks PN, but CNTFRα expression was still detected in certain layers. The three receptors were expressed in different retinal layers at the same timepoint. Bax expression was downregulated in, rhBDNF + rhCNTF, rhBDNF + rhNT-3, groups 2 weeks after intravitreal injection; Bcl-2 expression was upregulated in the rhBDNF + rhCNTF + rhNT-3 group at PN-4w; and LC3 expression was upregulated in rhBDNF + rhCNTF + rhNT-3 groups. Conclusions The combined use of neurotrophic factors had a more significant effect on Bax, Bcl-2, and LC3 expression than the same factors used alone.

Background Retinitis pigmentosa (RP) is the most common cause of blindness in retinal disease. Long-lasting ocular administration is an effective therapy to delay the progression of RP. And hydrogel sustained release system may be an available and stable drug carrier in the treatment of RP. Method Hydrogel sustained release system was constructed as a drug carrier of recombinant human erythropoietin (rhEPO). We administered retinal degenerative (rd) mice (Pdeb rd1 / Pdeb rd1 ) via subconjunctival or retrobulbar injection at postnatal 2 weeks (PN-2w), examined the mice and tested the factors of retina at two weeks after injection. Electroretinogram (ERG) was used to examine retinal function at PN-4w, western blot and q-PCR were used to test the expression of Bax, Bcl-2, iNOS and VEGFa of retina. Result Photoreceptor apoptosis were alleviated in all rhEPO administrated groups. The retinal blood supply was improved in injection groups. Compared with placebo and blank control groups, rhEPO treatment could enhance the retinal function and delay the progression of disease. Although there was no significant difference between rhEPO hydrogel and rhEPO treated group, photoreceptor apoptosis in rhEPO hydrogel group was less than that in rhEPO group, and the retinal function was better in rhEPO hydrogel group. Moreover, different routes of administration might have little effect on treatment in this research. Conclusion Early intervention can effectively control the progression of the disease. Anti-apoptosis,neuroprotection and erythropoietin of rhEPO could be useful in the treatment of RP. Hydrogel as a long-lasting drug sustained release system was stable and available, and might become a potential drug carrier in the future.

"AIM: To describe the complex, overlapping phenotype of four Chinese patients with inherited retinal dystrophies (IRDs) who harbored two pathogenic genes simultaneously. METHODS: This retrospective study included 4 patients affected with IRDs. Medical and ophthalmic histories were obtained, and clinical examinations were performed. A specific Hereditary Eye Disease Enrichment Panel (HEDEP) based on exome capture technology was used for genetic screening. RESULTS: Four patients were identified to harbor disease-causing variants in two different genes. Patient retinitis pigmentosa (RP) 01-II:1 exhibited both classical ABCA4 -induced Stargardt disease (STGD) 1 and USH2A-associated RP, patient RP02-III:2 exhibited both classical ABCA4-induced STGD1 and CDH23-associated RP, patient RP03-II:1 exhibited both USH2A-induced autosomal recessive retinitis pigmentosa (arRP) syndrome and SNRNP200-induced autosomal dominant retinitis pigmentosa (adRP), and patient RP04- II:2 exhibited USH2A-induced arRP syndrome and EYS-induced arRP at the same time. CONCLUSION: Our study demonstrates that genotype–phenotype correlations and comprehensive genetic screening is crucial for diagnosing IRDs and helping family planning for patients suffering from the disease."

Objectives To identify disease-causing mutations in two Chinese families with autosomal dominant retinitis pigmentosa (adRP). Design Prospective analysis. Patients Two Chinese adRP families underwent genetic diagnosis. A specific hereditary eye disease enrichment panel (HEDEP) based on targeted exome capture technology was used to collect the protein coding regions of targeted 371 hereditary eye disease genes; high throughput sequencing was done with the Illumina HiSeq 2000 platform. The identified variants were confirmed with Sanger sequencing. Setting All experiments were performed in a large laboratory specialising in genetic studies in the Department of Ophthalmology, Peking University Third Hospital. Results Two novel mutations, including one splice site mutation (Int10 c.1074-2 A>T; p.Y359SfsX29) and one insertion (c.824_825insA; p.Y275X) of PRPF31 were identified in the two families. The two mutations segregated with the disease phenotype in their respective families. Conclusions Our findings broaden the spectrum of PRPF31 mutations causing adRP and the phenotypic spectrum of the disease in Chinese patients. The HEDEP based on targeted exome capture technology is an efficient method for molecular diagnosis in adRP patients.