Relationship Between Macular Curvature and Common Causative Genes of Retinitis Pigmentosa in Japanese Patients

Abstract

PURPOSE. To determine the relationship between the macular curvature and the causative genes of retinitis pigmentosa (RP). METHODS. We examined the medical records of the right eyes of 65 cases with RP (31 men and 34 women; average age, 47.6 years). There were 31 cases with the EYS variants, 11 cases with the USH2A variants, six cases with the RPGR variants, 13 cases with the RP1 variants, and four cases with the RP1L1 variants. The mean curvature of Bruch's membrane was calculated within 6 mm of the fovea as the mean macular curvature index (MMCI, 1/μm). We used multiple linear regression analysis to determine the independence of the causative genes contributing to the MMCIs after adjustments for age, sex, axial length, and width of the ellipsoid zone. RESULTS. The median MMCI was −31.2 × 10 −5 /μm for the RPGR eyes, −16.5 × 10 −5 /μm for the RP1L1 eyes, −13.0 × 10 −5 /μm for the RP1 eyes, −9.8 × 10 −5 /μm for the EYS eyes, and −9.0 × 10 −5 /μm for the USH2A eyes. Compared with the EYS gene as the reference gene, the RPGR gene was significantly related to the MMCI values after adjusting for the other parameters (P = 5.30 × 10 −6). In contrast, the effects of the other genes, USH2A, RP1, and RP1L1, were not significantly different from that of the EYS gene (P = 0.26, P = 0.49, and P = 0.92, respectively). CONCLUSIONS. The RPGR gene had a stronger effect on the steep macular curvature than the other ciliopathy-related genes.

Novel compound heterozygous variants in the USH2A gene associated with autosomal recessive retinitis pigmentosa without hearing loss

“…The protein includes three regions: i) a large extracellular region with a signal peptide, a laminin N-terminal, 10 laminin epidermal growth factor-like domains, and 34 fibronectin type-III domains separated by 2 laminin G-like domains; ii) a transmembrane region; iii) a short intracellular region with a PDZ-binding motif at its C-terminal end ( Liu et al, 2007 ; Chen et al, 2014 ; Fu et al, 2020 ; Zhu et al, 2021 ). The USH2A variants, including missense, nonsense, duplications/insertions, deletions, indels, and splicing variants, spread throughout the 72 exons and their flanking intronic regions ( Aller et al, 2006 ; Koyanagi et al, 2020 ; Gao et al, 2021 ). Genotype-phenotype correlation has yet to be elucidated, while analyses based on some studies showed that patients with truncating variants may have more severe phenotypes, involving visual and auditory dysfunction ( Inaba et al, 2020 ; Meng et al, 2021 ).…”

“…It has wide phenotypic and genetic heterogeneity with numerous gene defects ( Ávila-Fernández et al, 2010 ; Gao et al, 2019 ; Karali et al, 2019 ). The disorder is typically characterized by progressive degeneration of rod photoreceptors, cone photoreceptors, and retinal pigment epithelium, leading to night blindness, restricted peripheral vision (tunnel vision), and reduction of central vision ( Hartong et al, 2006 ; Verbakel et al, 2018 ; Koyanagi et al, 2020 ). The estimated prevalence of the disorder is about 0.025%, and there are more than 1.5 million reported patients worldwide ( de Castro-Miró et al, 2014 ; Menghini et al, 2020 ; Sharon et al, 2020 ).…”

“…RP may be inherited in three patterns: autosomal recessive RP (ARRP), autosomal dominant RP (ADRP), and X-linked RP (XLRP), which account for 50%–60%, 30%–40%, and 5%–15% of patients, as well as some non-Mendelian inheritance traits ( Hartong et al, 2006 ; Ferrari et al, 2011 ; Chen et al, 2020 ; Dan et al, 2020 ). To date, at least 44 genes causing ARRP have been recorded in the Retinal Information Network ( https://web.sph.uth.edu/RetNet/ , updated on 10 January 2023) ( Méndez-Vidal et al, 2013 ; Caruso et al, 2020 ; Koyanagi et al, 2020 ). Among them, the usherin gene ( USH2A ) was reported to be responsible for 10%–15% of ARRP.…”

Use of ellipsoid zone width for predicting visual prognosis after cataract surgery in patients with retinitis pigmentosa

“…EZ width was defined as the distance between the temporal and nasal borders on the horizontal image or the superior and inferior borders on the vertical image of the EZ, where the EZ line disappeared. If the entire length of the EZ line exceeded the size of the OCT image, the borders of the EZ were set to be those of the OCT image [ 13 ]. In addition to the horizontal and vertical EZ widths, which were acquired from the horizontal and vertical OCT images, respectively, the average EZ width was calculated by averaging the horizontal and vertical EZ widths.…”

Discrepancy between fundus autofluorescence abnormality and visual field loss in Bietti crystalline dystrophy

“…If the length of the EZ line exceeded the size of the OCT image, the borders of the EZ were considered to be those of the OCT image. 17 The EZ width measurements were performed twice by one observer (D.S. ), and the average values were recorded.…”