Altered Splicing of LAMP2 in a Multigenerational Family from Latvia Affected by Danon Disease.

Background and Objectives: Danon disease is a multisystemic disorder associated with variants in the LAMP2 gene, mainly affecting the cardiac muscle. Here, we report a multigenerational family from Latvia with two male patients, hemizygous for a novel splice-affecting variant c.928+3A>G. Affected patients exhibit a cardiac phenotype, moderate mental disability, and mild retinal changes. Materials and Methods: Both patients underwent either exome or hypertrophic cardiomyopathy gene panel next-generation sequencing. The pathogenic variant effect was determined using reverse transcription, Sanger sequencing, and high-resolution electrophoresis. Results: Evaluation of the splicing process revealed that approximately 80% of the transcripts exhibited a lack of the entire exon 7. This alteration was predicted to cause a shift of the reading frame, consequently introducing a premature stop codon downstream in the sequence. Conclusions: Based on our data, we propose that c.928+3A>G is a pathogenic variant associated with Danon disease.

Solar retinopathy: a new setting of red, green, and blue channels.

PURPOSE: To introduce a new color imaging technique using improved settings of red, green, and blue channels for improved delineation of retinal damage in patients with solar retinopathy. METHOD: A retrospective case series of patients with poor vision secondary to solar retinopathy were analyzed. All patients underwent visual acuity, refraction, and dilated fundus examination. A spectral domain-optical coherence tomography of the macula and color fundus imaging using optimized red, green, and blue color setting was performed. Patients were reviewed over a 6-month period. The data were analyzed for statistical significance using an independent t test and a receiver operating characteristic curve. RESULTS: In total, 20 eyes of 10 patients were included between 2009 and 2017. The mean age was 24.9 ± 18.1 years. Best corrected visual acuity at first consultation was 0.78 ± 0.11 and after 6 months was 0.83 ± 0.09. Spectral domain-optical coherence tomography demonstrated retinal abnormalities at the myoid zone, ellipsoid zone, and the outer segment of photoreceptors. Receiver operating characteristic curve analysis showed an improving effect (area under the curve = 0.62; 95% confidence interval = 0.42-0.79). The color channels parameters, which improve visualization of the lesions were found to be 67-0.98-255 for the R-guided setting, 19-0.63-121 for the B-guided setting, and 7-1.00-129 for the G-guided setting. The ideal red, green, and blue setting was in 24-0.82-229. CONCLUSION: The use of a new setting of red, green, and blue channels could improve the diagnosis and monitoring of solar retinopathy, hence improving patient care.

Factors influencing myopic shift in children after intraocular lens implantation.

INTRODUCTION: Intraocular lenses have always been a controversial topic in pediatric cataract surgery. In the early 1990s in the post-Soviet states of Eastern Europe, intraocular lenses promised an easier full-time correction and amblyopia treatment. Since 1991, ophthalmologists in Latvia have been implanting intraocular lenses in infants. Amount of the postoperative myopic shift and its influencing factors, analyzed in this article, are important indicators of congenital cataract treatment. MATERIALS AND METHODS: A retrospective chart review off 85 children (137 eyes) who underwent foldable posterior chamber intraocular lens implantation at the Clinical University Hospital in Riga, Latvia, from 1 January 2006 until 31 December 2016, was performed. Depending on the age at surgery, patients were divided into six groups: 1-6, 7-12, 13-24, 25-48, 49-84, and 85-216 months. RESULTS: The largest and more variable myopic shift was found in a group of diffuse/total and nuclear cataract with surgery before the age of 6 months. There was a statistically significant correlation between the acquired best-corrected visual acuity and the amount of myopic shift (rs = 0.33; p < 0.001). Comparing the amount of myopic shift in two groups of different intraocular lens implantation target refraction tactics, we did not find statistically significant differences. Comparing the amount of myopic shift and implanted intraocular lens power, a negative, statistically significant correlation was found. CONCLUSION: The earlier the cataract extraction surgery and intraocular lens implantation is performed, the larger the myopic shift. The morphological type of cataract, best-corrected visual acuity, secondary glaucoma, and intraocular lens power influence the amount of myopic shift.

Genetic linkage studies of a North Carolina macular dystrophy family.

BACKGROUND AND OBJECTIVE: North Carolina macular dystrophy (NCMD) is a very rare autosomal dominant hereditary disease. Up to date there are three types of NCMD described and consequently named macular dystrophy, retinal: MCDR1, MCDR2 and MCDR3. The aim of this study was to perform linkage and copy number variation analysis for the family affected by NCMD followed by the selected candidate gene sequencing. MATERIALS AND METHODS: This study concerned a 3-generation, non-consanguineous Latvian family with NCMD. Genome-wide scan, copy number variation and non-parametric linkage analysis was performed. Analysis resolved the locus of interest to the 5p15.33 region. Two of the genes, iroquois homeobox 2 (IRX2) and iroquois homeobox 4 (IRX4), were selected and sanger sequencing was performed. RESULTS: Linkage analysis indicated a region on chromosome 5 for the analyzed family, corresponding to a genetic locus previously described for MCDR3 (5p15-p13). Chromosomal aberrations were not identified in the affected family members. An upstream intron variant (NM_001278634: c.-139G > A (rs6876836)) in IRX4 gene segregated with NCMD phenotype in the analyzed family. CONCLUSIONS: It is unlikely to be the causative mutation of NCMD due to its high minor allele frequency 0.3532. Therefore, the role of IRX2 and IRX4 genes in the pathogenesis of NCMD has not been proved. Considerable variability in visual acuity between individuals of the same age group in all the families examined was noted. No overlap between NCMD grade and family generation was seen in the family described in the present study.

Fabricated or Induced Illness Presenting as Recurrent Corneal Lesions, Cataracts, and Uveitis.

Two siblings with ophthalmic findings, psychomotor retardation, somnolence, and seizures underwent diagnostic studies, genetic investigations, ultrasonography, biomicroscopy, and posterior and anterior optical coherence tomography. Both siblings experienced eye problems at different times from the age of 6 months to 12 years. The family pedigree and neurological problems (ie, hypotony, seizures, sleepiness, and speech and psychomotor delay) suggested a metabolic or mitochondrial pathology. After exclusion of multiple potential diseases, a fabricated or induced illness was suspected. Fabricated or induced illness can be a cause for unusual clinical findings and should be considered in the differential diagnosis when ocular and other abnormalities cannot be explained after a comprehensive evaluation. The diagnosis of fabricated or induced illness should not be based on exclusion alone but rather on positive findings.

Presentation of Complex Homozygous Allele in ABCA4 Gene in a Patient with Retinitis Pigmentosa.

Retinitis pigmentosa is a degenerative retinal disease characterized by progressive photoreceptor damage, which causes loss of peripheral and night vision and the development of tunnel vision and may result in loss of central vision. This study describes a patient with retinitis pigmentosa caused by a mutation in the ABCA4 gene with complex allele c.1622T>C, p.L541P; c.3113C>T, p.A1038V in homozygous state.

Point mutations associated with Leber hereditary optic neuropathy in a Latvian population.

PURPOSE: To study mutations associated with Leber hereditary optic neuropathy (LHON) in patients suspected of having this mitochondrial disorder in a Latvian population. Additional aims were to determine the heteroplasmy status of all non-synonymous polymorphisms identified in the current study and to identify the mitochondrial haplogroups of the studied participants because these factors may contribute to the manifestation of LHON. METHODS: Twelve patients, including patients in two families, were enrolled in the current study. LHON was suspected based on the findings of ophthalmologic examinations. In clinically affected individuals, the presence of all previously reported LHON-associated mutations was assessed with sequencing analysis. Additionally, the SURVEYOR endonuclease assay was used to detect heteroplasmy. The mitochondrial haplogroups were identified with restriction analysis and the sequencing of hypervariable segment 1. RESULTS: In one family (mother and son), there was one primary LHON-associated mutation, G11778A. In addition, one rare previously reported LHON-associated polymorphism, A13637G, was detected in two unrelated patients. A non-synonymous polymorphism at T6253C was found in one individual. This mutation was reported in the background of the 3460 mutation among LHON patients in a Chinese population. No non-synonymous point mutations in mitochondrial DNA were found in five of the study participants. CONCLUSIONS: Molecular analysis of 12 patients with suspected LHON confirmed the diagnosis in four patients and allowed the use of appropriate prophylactic measures and treatment. Further investigations and additional studies of different populations are necessary to confirm the role of the non-synonymous polymorphisms A13637G and T6253C in the manifestation of LHON and the associations of these polymorphisms with mitochondrial haplogroups and heteroplasmy.