Detailed analysis of family with autosomal recessive bestrophinopathy associated with new BEST1 mutation.

PURPOSE: To describe the clinical and genetic findings in a patient with autosomal recessive bestrophinopathy (ARB) and his healthy parents. METHODS: The patient and his healthy non-consanguineous parents underwent detailed ophthalmic evaluations including electro-oculography (EOG), spectral-domain optical coherence tomography (SD-OCT), and fundus autofluorescence (FAF) imaging. Mutation analysis of the BEST1 gene was performed by Sanger sequencing. RESULTS: The FAF images showed multiple spots of increased autofluorescence, and the sites of these spots corresponded to the yellowish deposits detected by ophthalmoscopy. SD-OCT showed cystoid macular changes and a shallow serous macular detachment. The Arden ratio of the EOG was markedly reduced to 1.1 in both eyes. Genetic analysis of the proband detected two sequence variants of the BEST1 gene in the heterozygous state: a novel variant c.717delG, p.V239VfsX2 and an already described c.763C>T, p.R255W variant associated with Best vitelliform macular dystrophy and ARB. The proband's father carried the c.717delG, p.V239VfsX2 variant in the heterozygous state, and the mother carried the c.763C>T, p.R255W variant in the heterozygous state. The parents who were heterozygous for the BEST1 variants had normal visual acuity, EOG, SD-OCT, and FAF images. CONCLUSIONS: In a truncating BEST1 mutation, the phenotype associated with ARB is most likely due to a marked decrease in the expression of BEST1 promoted by the nonsense-mediated decay surveillance mechanism, and it may depend on the position of the premature termination of the codon created.

High-Resolution Retinal Imaging Reveals Preserved Cone Photoreceptor Density and Choroidal Thickness in Female Carriers of Choroideremia.

BACKGROUND AND OBJECTIVE: To characterize the photoreceptors and choroidal morphology of heterozygous female carriers of choroideremia who typically do not have any visual defects but can have severe funduscopic changes. PATIENTS AND METHODS: This was a clinical case series study. Detailed ophthalmic examinations were performed on six female carriers from four families with choroideremia. The subfoveal choroidal thickness (SFCT) was determined by spectral-domain optical coherence tomography (SD-OCT) and the cone photoreceptor density by adaptive optics (AO) retinal imaging. SFCT and cone densities of the carriers were compared to that of normal eyes of healthy subjects. RESULTS: The mean age of the carriers was 42.5 years. Fundus photographs showed diffuse, patchy depigmentation; however, the SFCT was within the normal limits. AO retinal imaging revealed preserved cone densities at temporal eccentricities from 2 to 8 angular degrees. CONCLUSIONS: The findings indicate that despite the presence of distinctive depigmentation of the retinal pigment epithelium in female carriers of choroideremia, their cone photoreceptor densities and SFCT are well-preserved. These observations may account for the good visual acuity and lack of an awareness of visual disturbances. [Ophthalmic Surg Lasers Imaging Retina. 2019;50:76-85.].

CEP250 mutations associated with mild cone-rod dystrophy and sensorineural hearing loss in a Japanese family.

BACKGROUND: CEP250 encodes the C-Nap1 protein which belongs to the CEP family of proteins. C-Nap1 has been reported to be expressed in the photoreceptor cilia and is known to interact with other ciliary proteins. Mutations of CEP250 cause atypical Usher syndrome which is characterized by early-onset sensorineural hearing loss (SNHL) and a relatively mild retinitis pigmentosa. This study tested the hypothesis that the mild cone-rod dystrophy (CRD) and SNHL in a non-consanguineous Japanese family was caused by CEP250 mutations. METHODS: Detailed ophthalmic and auditory examinations were performed on the proband and her family members. Whole exome sequencing (WES) was used on the DNA obtained from the proband. RESULTS: Electrophysiological analysis revealed a mild CRD in two family members. Adaptive optics (AO) imaging showed reduced cone density around the fovea. Auditory examinations showed a slight SNHL in both patients. WES of the proband identified compound heterozygous variants c.361C>T, p.R121*, and c.562C>T, p.R188* in CEP250. The variants were found to co-segregate with the disease in five members of the family. CONCLUSIONS: The variants of CEP250 are both null variants and according to American College of Medical Genetics and Genomics (ACMG) standards and guideline, these variants are classified into the very strong category (PVS1). The criteria for both alleles will be pathogenic. Our data indicate that mutations of CEP250 can cause mild CRD and SNHL in Japanese patients. Because the ophthalmological phenotypes were very mild, high-resolution retinal imaging analysis, such as AO, will be helpful in diagnosing CEP250-associated disease.

High-Resolution Adaptive Optics Retinal Image Analysis at Early Stage Central Areolar Choroidal Dystrophy With PRPH2 Mutation.

BACKGROUND AND OBJECTIVE: To report the clinical features of Japanese patients at Stage 1 and 2 of central areolar choroidal dystrophy (CACD). PATIENTS AND METHODS: Five family members had comprehensive ophthalmic examinations including adaptive optics (AO) retinal imaging. Mutation analysis of the PRPH2 gene was performed by Sanger sequencing. The protocol conformed to the tenets of the Declaration of Helsinki and was approved by the institutional review board of The Jikei University School of Medicine. RESULTS: Four family members had a heterozygous PRPH2 mutation, p.R172Q; however, one member with a mutation did not show any ophthalmological abnormalities. Two patients had mild parafoveal retinal dystrophy and a reduction of cone density determined by AO analysis. CONCLUSION: The results indicate that the parafoveal cone photoreceptors can be affected even at the early stage of CACD. [Ophthalmic Surg Lasers Imaging Retina. 2016;47:1115-1126.].

Detailed Morphological Changes of Foveoschisis in Patient with X-Linked Retinoschisis Detected by SD-OCT and Adaptive Optics Fundus Camera.

Purpose. To report the morphological and functional changes associated with a regression of foveoschisis in a patient with X-linked retinoschisis (XLRS). Methods. A 42-year-old man with XLRS underwent genetic analysis and detailed ophthalmic examinations. Functional assessments included best-corrected visual acuity (BCVA), full-field electroretinograms (ERGs), and multifocal ERGs (mfERGs). Morphological assessments included fundus photography, spectral-domain optical coherence tomography (SD-OCT), and adaptive optics (AO) fundus imaging. After the baseline clinical data were obtained, topical dorzolamide was applied to the patient. The patient was followed for 24 months. Results. A reported RS1 gene mutation was found (P203L) in the patient. At the baseline, his decimal BCVA was 0.15 in the right and 0.3 in the left eye. Fundus photographs showed bilateral spoke wheel-appearing maculopathy. SD-OCT confirmed the foveoschisis in the left eye. The AO images of the left eye showed spoke wheel retinal folds, and the folds were thinner than those in fundus photographs. During the follow-up period, the foveal thickness in the SD-OCT images and the number of retinal folds in the AO images were reduced. Conclusions. We have presented the detailed morphological changes of foveoschisis in a patient with XLRS detected by SD-OCT and AO fundus camera. However, the findings do not indicate whether the changes were influenced by topical dorzolamide or the natural history.

Cone dystrophy in patient with homozygous RP1L1 mutation.

The purpose of this study was to determine whether an autosomal recessive cone dystrophy was caused by a homozygous RP1L1 mutation. A family including one subject affected with cone dystrophy and four unaffected members without evidence of consanguinity underwent detailed ophthalmic evaluations. The ellipsoid and interdigitation zones on the spectral-domain optical coherence tomography images were disorganized in the proband. The proband had a reduced amplitude of cone and flicker full-field electroretinograms (ERGs). Focal macular ERGs and multifocal ERGs were severely reduced in the proband. A homozygous RP1L1 mutation (c.3628T>C, p.S1210P) was identified in the proband. Family members who were heterozygous for the p.S1210P mutation had normal visual acuity and normal results of clinical evaluations. To investigate other putative pathogenic variant(s), a next-generation sequencing (NGS) approach was applied to the proband. NGS identified missense changes in the heterozygous state of the PCDH15, RPGRIP1, and GPR98 genes. None of these variants cosegregated with the phenotype and were predicted to be benign reinforcing the putative pathogenicity of the RP1L1 homozygous mutation. The AO images showed a severe reduction of the cone density in the proband. Our findings indicate that a homozygous p.S1210P exchange in the RP1L1 gene can cause cone dystrophy.

High-Resolution Imaging of Patients with Bietti Crystalline Dystrophy with CYP4V2 Mutation.

The purpose of this study was to determine the retinal morphology of eyes with Bietti crystalline dystrophy (BCD) associated with a CYP4V2 mutation using high-resolution imaging techniques. Three subjects with BCD underwent detailed ophthalmic examinations. High-resolution fundus images were obtained with an adaptive optics (AO) fundus camera. A common homozygous mutation was detected in the three patients. Funduscopic examination of the three patients revealed the presence of crystalline deposits in the retina, and all of the crystalline deposits were also detected in the infrared (IR) images. The crystals observed in the IR images were seen as bright reflective plaques located on the RPE layer in the SD-OCT images. The clusters of hyperreflective signals in the AO images corresponded to the crystals in the IR images. High-magnification AO images revealed that the clusters of hyperreflective signals consisted of circular spots that are similar to the signals of cone photoreceptors. Most of these circular spots were detected in healthy areas in the FAF images. There is a possibility that circular spots observed by AO are residual cone photoreceptors located over the crystals.