Beyond the phenotype: Exploring inherited retinal diseases with targeted next-generation sequencing in a Turkish cohort.

This research aims to compile recent clinical and genetic data from Turkish patients with inherited retinal disorders and evaluate the effectiveness of targeted Next-generation sequencing panels. The study included Turkish individuals with hereditary retinal diseases who visited the Medical Genetic Department of Erciyes University between 2019 and 2022. One proband per family was selected based on eligibility. We used Hereditary Disorder Solution (HDS) by Sophia Genetics and performed next-generation sequencing (NGS) with Illumina NextSeq-500. Bioinformatics analysis using Sophia DDM® SaaS algorithms and ACMG guidelines classified genomic changes. The study involved 354 probands. Disease-causing variants were found in 58.1% of patients, with ABCA4, USH2A, RDH12, and EYS being the most frequently implicated genes. Forty-eight novel variants were detected. This study enhances the knowledge of clinical diagnoses, symptom onset, inheritance patterns, and genetic details for Turkish individuals with hereditary retinal disease. It contributes to broader health strategies by enabling comparisons with other studies.

ABCA4 variant screening in a Turkish cohort with Stargardt disease.

PURPOSE: This study aims to evaluate the ABCA4 variants in patients diagnosed with Stargardt disease. METHODS: This is a retrospective study designed to investigate variants in the ABCA4 in Stargardt disease and the clinical findings of the cases. Sex, age, age of onset of symptoms, best-corrected visual acuity, color fundus photography, optical coherence tomography, and visual field test of the patients were recorded. Genetic analyses were screened, and patients with at least two variants in the ABCA4 were included in this study. RESULTS: Twenty-seven patients diagnosed with Stargardt disease with the ABCA4 variants were included in this study. Twelve of them (44.4%) were female and fifteen (55.5%) were male. The mean age of the cases was 27.44 years (ranging from 8 to 56 years). Thirty different variants were detected in 54 ABCA4 alleles of 27 patients. The two most common pathogenic variants were c.5882 G>A p.(Gly1961Glu) and c.52C>T p.(Arg18Trp) in this cohort. Two novel variants were identified (c.3855_3856dup, c.1554 + 3_1554 + 4del) and the patient with the c.1554 + 3_1554 + 4del variant additionally had a different ABCA4 variant in trans. The other novel variant was homozygous. CONCLUSIONS: In this study, two novel variants were described in a Turkish cohort with Stargardt disease. The variant c.52C>T p.(Arg18Trp) was the most common disease-causing variant besides the c.5882 G>A p.(Gly1961Glu) which was identified frequently in the previous studies. A larger sample size is necessary for describing different pathogenic variants and understanding the phenotype-genotype correlations.

Identifying variants and their pathogenicity in inherited diseases is important for widening the disease-causing mutations and future treatment options.Two novel variants (c.3855_3856dup, c.5910_5912dup) were described in a cohort with Stargardt disease.The most common variants could be different in ethnic groups.The variant c.52C>T p.(Arg18Trp) was the most common variant besides the c.5882G>A p.(Gly1961Glu) which was frequently identified in the previous studies.Describing different pathogenic variants and clinical findings of the patients is important for understanding the phenotype-genotype correlations.

Effect of Transcorneal Electrical Stimulation on Patients with Retinitis Pigmentosa.

Purpose: In this study, the aim was to evaluate the safety of transcorneal electrical stimulation (TES) treatment in retinitis pigmentosa (RP) patients and to investigate the effect of TES to the visual acuity (VA), visual field (VF), and multifocal electroretinogram (mfERG) findings. Methods: Two hundred two eyes of 101 RP patients with different stages were studied. TES was applied for 30 min once a week for 8 consecutive weeks. Two hundred eyes of 100 RP patients were enrolled as control. After the 2-month TES therapy sessions, patients were followed for 4 months without treatment. Examinations were done at the baseline before TES treatment and 1 and 6 months after the treatment. Best-corrected VA (BCVA), color fundus photography, VF test, optical coherence tomography, and mfERG tests were done at each visit. Results: The mean BCVA and VF tests improved 1 month after the beginning of TES treatment and the improvements were statistically significant (P < 0.05). There was an improvement in p1 wave amplitude in rings 1, 2, and 3 at the first month. The latency of the p1 wave showed a statistically significant shortening in rings 1 and 2. These improvements partially disappeared at 6-month follow-up. There were no serious ocular side effects related to the therapy. Mild dry eye symptoms were observed, which were revealed by artificial tears. Conclusions: TES is a safe therapy without any serious advers effects. Although it can improve VA and VF of RP patients, the beneficial effects could be transient and repeated sessions can be necessary for maintaining the efficiency.

Six-month results of suprachoroidal adipose tissue-derived mesenchymal stem cell implantation in patients with optic atrophy: a phase 1/2 study.

PURPOSE: This prospective clinical case series aimed to investigate the safety and efficacy of suprachoroidal adipose tissue-derived mesenchymal stem cell (ADMSC) implantation in patients with optic nerve diseases. METHODS: This prospective, single-center, phase 1/2 study enrolled 4 eyes of 4 patients with optic atrophy of various reasons who underwent suprachoroidal implantation of ADMSCs. The best-corrected visual acuity (BCVA) in the study was HM at 1 m. The worse eye of the patient was operated. Patients were evaluated on the first day, first week, first month, third and sixth months postoperatively. BCVA, anterior segment and fundus examination, color photography, optical coherence tomography (OCT) and visual field examination were carried out at each visit. Fundus fluorescein angiography and multifocal electroretinography (mfERG) recordings were performed at the end of the first, third and sixth months and anytime if necessary during the follow-up. RESULTS: All 4 patients completed the six-month follow-up. None of them had any systemic or ocular complications. All of the patients experienced visual acuity improvement, visual field improvement and improvement in the mfERG recordings. We found choroidal thickening in OCT of the 4 patients. CONCLUSION: Even though the sample size is small, the improvements were still encouraging. Stem cell treatment with suprachoroidal implantation of ADMSCs seems to be safe and effective in the treatment for optic nerve diseases that currently have no curative treatment options.