Identification of Pathogenic Copy Number Variants in Mexican Patients With Inherited Retinal Dystrophies Applying an Exome Sequencing Data-Based Read-Depth Approach.

BACKGROUND: Retinal dystrophies (RDs) are the most common cause of inherited blindness worldwide and are caused by genetic defects in about 300 different genes. While targeted next-generation sequencing (NGS) has been demonstrated to be a reliable and efficient method to identify RD disease-causing variants, it doesn't routinely identify pathogenic structural variant as copy number variations (CNVs). Targeted NGS-based CNV detection has become a crucial step for RDs molecular diagnosis, particularly in cases without identified causative single nucleotide or Indels variants. Herein, we report the exome sequencing (ES) data-based read-depth bioinformatic analysis in a group of 30 unrelated Mexican RD patients with a negative or inconclusive genetic result after ES. METHODS: CNV detection was performed using ExomeDepth software, an R package designed to detect CNVs using exome data. Bioinformatic validation of identified CNVs was conducted through a commercially available CNV caller. All identified candidate pathogenic CNVs were orthogonally verified through quantitative PCR assays. RESULTS: Pathogenic or likely pathogenic CNVs were identified in 6 out of 30 cases (20%), and of them, a definitive molecular diagnosis was reached in 5 cases, for a final diagnostic rate of ~17%. CNV-carrying genes included CLN3 (2 cases), ABCA4 (novel deletion), EYS, and RPGRIP1. CONCLUSIONS: Our results indicate that bioinformatic analysis of ES data is a reliable method for pathogenic CNV detection and that it should be incorporated in cases with a negative or inconclusive molecular result after ES.

Familial fleck corneal dystrophy caused by complete deletion of the PIKFYVE gene.

BACKGROUND: Fleck corneal dystrophy (FCD) is a rare autosomal dominant disease that affects exclusively the corneal stroma. The disease is caused by heterozygous variants in PIKFYVE, a gene encoding a lipid kinase involved in multiple cellular pathways, primarily participating in membrane dynamics and signaling. This report describes a familial case of FCD caused by a complete deletion of the PIKFYVE gene. MATERIAL AND METHODS: A clinical ophthalmic examination was performed on the proband and family members. Genetic testing included next-generation sequencing (multigene panel), and chromosomal microarray analysis. A quantitative PCR assay was designed in order to segregate the deletion. RESULTS: A 19-year-old male, with no family or personal history of ocular disease, presented for evaluation due to an acute illness consisting of burning, foreign body sensation, and red eye. Slit lamp biomicroscopy revealed bilateral small pterygia and scattered bilateral white opacities in the corneal stroma, a very similar corneal phenotype was found in the 47-year-old father, who was asymptomatic. NGS detected a heterozygous deletion of the entire PIKFYVE coding sequence. CMA in DNA from the propositus indicated a 543 kb deletion in 2q33.3q34 spanning the entire PIKFYVE gene. The deletion was confirmed in the father. CONCLUSIONS: We add to the molecular spectrum of FCD by describing a familial case of a whole PIKFYVE gene deletion in affected subjects. Our findings support that normal expression of PIKFYVE is necessary for corneal keratocytes homeostasis and normal corneal appearance. We conclude that PIKFYVE haploinsufficiency is the molecular mechanism underlying this familial case of FCD.

Dysgerminoma Probably Due to a Novel SOHLH1-pathogenic Variant Causing Familial Ovarian Dysgenesis.

Pathogenic variants of the SOHLH1 gene are responsible for an autosomal recessive form of ovarian dysgenesis; this gene encodes a transcription factor expressed early in spermatogonia and oocytes and contributes to folliculogenesis. Previously, four affected women from two unrelated families reported homozygous variants in the SOHLH1 gene, but none had a history of gonadal malignancy or a histologic description. We present two sisters and their paternal great-aunt with a history of primary amenorrhea, pubertal delay, and hypergonadotrophism who came from an inbred Mexican family. The proband was the younger sister who was referred for bilateral dysgerminoma. She had a normal blood karyotype, and whole-exome sequencing analysis revealed a novel homozygous missense variant, c.275C>T, in SOHLH1; several family members were also analyzed. In addition to pure dysgerminoma, histopathological analysis revealed an ovarian cortex with fibrosis and almost total absence of follicles. This work confirms the inheritance of ovarian dysgenesis 5, supports the occurrence of cell loss in mouse models, and suggests that affected women should undergo periodic imaging surveillance due to the likely risk of tumor development.

Mutational Profile and Retinal Phenotypes of PCARE-Related Cone-Rod Dystrophies in a Mexican Cohort.

Purpose: The aim of the study is to describe the genotype and phenotype of a Mexican cohort with PCARE-related retinal disease. Methods: The study included 14 patients from 11 unrelated pedigrees with retinal dystrophies who were demonstrated to carry biallelic pathogenic variants in PCARE. Visual assessment methods included best corrected visual acuity, color fundus photography, Goldmann visual field test, kinetic perimetry, dark/light adapted chromatic perimetry, full-field electroretinography, autofluorescence imaging, and spectral domain-optical coherence tomography imaging. Genetic screening was performed either by gene panel sequencing or by exome sequencing. Results: According to the results of multimodal imaging and functional tests, all 14 patients were diagnosed with cone-rod dystrophy. Six different PCARE pathogenic alleles were identified in our cohort, including three novel mutations: c.3048_3049del (p.Tyr1016∗), c.3314_3315del (p.Ser1105∗), and c.551A > G (p.His184Arg). Notably, alleles p.His184Arg, p.Arg613∗, and p.Arg984∗ were present in 18 of the 22 (82%) PCARE alleles from probands in our cohort. Conclusion: Our work expands the PCARE mutational profile by identifying three novel pathogenic variants causing retinal dystrophy. While phenotypic variations occurred among patients, a cone-rod dystrophy pattern was observed in all affected individuals.

Identification of Genetic Variants for Diabetic Retinopathy Risk Applying Exome Sequencing in Extreme Phenotypes.

Background: Diabetic retinopathy (DR) risk has been shown to vary depending on ethnic backgrounds, and thus, it is worthy that underrepresented populations are analyzed for the potential identification of DR-associated genetic variants. We conducted a case-control study for the identification of DR-risk variants in Mexican population. Methods: We ascertained 60 type 2 diabetes mellitus (T2DM) patients. Cases (n = 30) were patients with advanced proliferative DR (PDR) with less than 15 years after a T2DM diagnosis while controls (n = 30) were patients with no DR 15 years after the diagnosis of T2DM. Exome sequencing was performed in all patients, and the frequency of rare variants was compared. In addition, the frequency of variants occurring in a set of 169 DR-associated genes were compared. Results: Statistically significant differences were identified for rare missense and splice variants and for rare splice variants occurring more than once in either group. A strong statistical difference was observed when the number of rare missense variants with an aggregated prediction of pathogenicity and occurring more than once in either group was compared (p = 0.0035). Moreover, 8 variants identified more than once in either group, occurring in previously identified DR-associated genes were recognized. The p.Pro234Ser KIR2DS4 variant showed a strong protective effect (OR = 0.04 [0.001-0.36]; p = 0.04). Conclusions: Our study showed an enrichment of rare splice acceptor/donor variants in patients with PDR and identified a potential protective variant in KIR2DS4. Although statistical significance was not reached, our results support the replication of 8 previously identified DR-associated genes.

Learning from history in the midst of the COVID-19: epidemics/pandemics of antiquity up to the fall of the Western Roman Empire.

When humans discovered agriculture and livestock, they ceased to be nomads and began to settle in towns until they created large cities. From the first human settlements in Egypt, Mesopotamia, and the Anatolian Peninsula, populations were exposed and susceptible to new infectious agents, leading to epidemics and pandemics. Great civilizations emerged, such as Egypt, the land of Hatti, Israel, Greece, Carthage, and Rome, among others. Contact between different populations through wars or maritime trade is well documented and has been described as a source of epidemics throughout history. Epidemics described as plagues or pestilences, such as those of Egypt, the Hebrews, or the Hittites, are based on biblical texts or evidence such as tablets or hieroglyphic writings. We also reviewed classical books by authors such as Homer, Aeschylus, Herodotus of Halicarnassus, Thucydides, Diodorus Siculus, Dionysius of Halicarnassus, Titus Livius, Suetonius, and others; and described all epidemics/pandemics chronologically. This article describes the epidemics/pandemics for which there is written evidence from ancient Egypt to the fall of the Roman Empire. We should not be surprised when new epidemics/pandemics appear as causes of political and economic collapse, as this has been common throughout history, decimating, blocking, or even destroying cultures and civilizations repeatedly.

Cuando el hombre descubrió la agricultura y la ganadería, dejó de ser nómada y empezó a asentarse en pueblos hasta crear grandes ciudades. Desde los primeros asentamientos humanos en Egipto, Mesopotamia y la península de Anatolia, las poblaciones estuvieron expuestas y susceptibles a nuevos agentes infecciosos, dando lugar a epidemias y pandemias. Aparecieron grandes civilizaciones como Egipto, la Tierra de Hatti, Israel, Grecia, Cartago y Roma, entre otras. El contacto entre las distintas poblaciones a través de las guerras o el comercio marítimo está muy bien establecido y descrito como focos de epidemias a lo largo de la historia. Las epidemias descritas como plagas o pestilencias, como las que ocurrieron a los egipcios, los judíos, o los hititas, se describen con base en textos bíblicos o mediante evidencias como tablillas o escritos jeroglíficos. También revisamos libros clásicos de autores como Homero, Esquilo, Herodoto de Halicarnaso, Tucídides, Diodoro Sículo, Dionisio de Halicarnaso, Tito Livio, Suetonio, entre otros. Este artículo describe cronológicamente todas las epidemias/pandemias de las que existe evidencia a través de la escritura desde el antiguo Egipto hasta la caída del Imperio Romano. No debemos sorprendernos cuando aparecen nuevas epidemias/pandemias como causantes del colapso político y económico, ya que ha sido algo común a lo largo de la historia, diezmando, bloqueando o incluso destruyendo culturas y civilizaciones reiteradamente.

Learning from history in the midst of the COVID-19: epidemics/pandemics of antiquity up to the fall of the Western Roman Empire / Aprendiendo de la historia en medio del COVID-19: epidemias/pandemias de la antigüedad hasta la caída del Imperio Romano de Occidente

Abstract When humans discovered agriculture and livestock, they ceased to be nomads and began to settle in towns until they created large cities. From the first human settlements in Egypt, Mesopotamia, and the Anatolian Peninsula, populations were exposed and susceptible to new infectious agents, leading to epidemics and pandemics. Great civilizations emerged, such as Egypt, the land of Hatti, Israel, Greece, Carthage, and Rome, among others. Contact between different populations through wars or maritime trade is well documented and has been described as a source of epidemics throughout history. Epidemics described as plagues or pestilences, such as those of Egypt, the Hebrews, or the Hittites, are based on biblical texts or evidence such as tablets or hieroglyphic writings. We also reviewed classical books by authors such as Homer, Aeschylus, Herodotus of Halicarnassus, Thucydides, Diodorus Siculus, Dionysius of Halicarnassus, Titus Livius, Suetonius, and others; and described all epidemics/pandemics chronologically. This article describes the epidemics/pandemics for which there is written evidence from ancient Egypt to the fall of the Roman Empire. We should not be surprised when new epidemics/pandemics appear as causes of political and economic collapse, as this has been common throughout history, decimating, blocking, or even destroying cultures and civilizations repeatedly.

Resumen Cuando el hombre descubrió la agricultura y la ganadería, dejó de ser nómada y empezó a asentarse en pueblos hasta crear grandes ciudades. Desde los primeros asentamientos humanos en Egipto, Mesopotamia y la península de Anatolia, las poblaciones estuvieron expuestas y susceptibles a nuevos agentes infecciosos, dando lugar a epidemias y pandemias. Aparecieron grandes civilizaciones como Egipto, la Tierra de Hatti, Israel, Grecia, Cartago y Roma, entre otras. El contacto entre las distintas poblaciones a través de las guerras o el comercio marítimo está muy bien establecido y descrito como focos de epidemias a lo largo de la historia. Las epidemias descritas como plagas o pestilencias, como las que ocurrieron a los egipcios, los judíos, o los hititas, se describen con base en textos bíblicos o mediante evidencias como tablillas o escritos jeroglíficos. También revisamos libros clásicos de autores como Homero, Esquilo, Herodoto de Halicarnaso, Tucídides, Diodoro Sículo, Dionisio de Halicarnaso, Tito Livio, Suetonio, entre otros. Este artículo describe cronológicamente todas las epidemias/pandemias de las que existe evidencia a través de la escritura desde el antiguo Egipto hasta la caída del Imperio Romano. No debemos sorprendernos cuando aparecen nuevas epidemias/pandemias como causantes del colapso político y económico, ya que ha sido algo común a lo largo de la historia, diezmando, bloqueando o incluso destruyendo culturas y civilizaciones reiteradamente.

X-linked juvenile retinoschisis associated with an RS1 in-frame deletion and bilateral central serous chorioretinopathy.

PURPOSE: To report the case of a patient with X-linked juvenile retinoschisis (XLRS), caused by an in-frame deletion of the RS1 gene, who presented visual loss due to bilateral central serous chorioretinopathy (CSC).Methods: Observational case report. RESULTS: A 34-year-old man, with type-A personality, presented with a one-month history of decreased visual acuity and metamorphopsia in his right eye. Funduscopic examination showed a dome-like foveal elevation in both eyes (OU), as well as subtle pigmentary changes of the retinal pigment epithelium with a tapetal reflex in the fovea. Spectral-domain optical coherence tomography revealed intraretinal cystic foveal changes and serous retinal detachment in OU. Fundus fluorescein angiography of OU showed a focal area of intense hyperfluorescence with leakage in late phases. Electroretinogram revealed a markedly attenuated b-wave and a diminished a-wave in photopic and scotopic phases. Genetic testing revealed a hemizygous c.282_284delCTT deletion in the RS1 gene, predicting a p.Ser95del change at the protein level. The patient was diagnosed with XLRS and central serous chorioretinopathy as a coexisting condition. Patient was observed during a 3-month period but showed no improvement. Therefore, subthreshold micropulse laser was applied, achieving complete resolution of signs and symptoms of CSC. CONCLUSION: CSC can be a cause of acute or subacute visual loss in patients with XLRS when other complications such as vitreous hemorrhage and retinal detachment have been excluded.

Exogenous CFH Modulates Levels of Pro-Inflammatory Mediators to Prevent Oxidative Damage of Retinal Pigment Epithelial Cells with the At-Risk CFH Y402H Variant.

Age-related macular degeneration (AMD) is a complex, progressive degenerative retinal disease. Retinal pigment epithelial (RPE) cells play an important role in the immune defense of the eye and their dysfunction leads to the progressive irreversible degeneration of photoreceptors. Genetic factors, chronic inflammation, and oxidative stress have been implicated in AMD pathogenesis. Oxidative stress causes RPE injury, resulting in a chronic inflammatory response and cell death. The Y402H polymorphism in the complement factor H (CFH) protein is an important risk factor for AMD. However, the functional significance of CFH Y402H polymorphism remains unclear. In the present study, we investigated the role of CFH in the pro-inflammatory response using an in vitro model of oxidative stress in the RPE with the at-risk CFH Y402H variant. ARPE-19 cells with the at-risk CFH Y402H variant were highly susceptible to damage caused by oxidative stress, with increased levels of inflammatory mediators and pro-apoptotic factors that lead to cell death. Pretreatment of the ARPE-19 cell cultures with exogenous CFH prior to the induction of oxidative stress prevented damage and cell death. This protective effect may be related to the negative regulation of pro-inflammatory cytokines. CFH contributes to cell homeostasis and is required to modulate the pro-inflammatory cytokine response under oxidative stress in the ARPE-19 cells with the at-risk CFH Y402H variant.

USH2A mutational spectrum causing syndromic and non-syndromic retinal dystrophies in a large cohort of Mexican patients.

Background: Mutations in the USH2A gene are the leading cause of both non-syndromic autosomal recessive retinitis pigmentosa (RP) and Usher syndrome, a syndromic form of RP characterized by retinal dystrophy and sensorineural hearing loss. To contribute to the expansion of the USH2A-related molecular spectrum, the results of genetic screening in a large cohort of Mexican patients are presented. Methods: The study population comprised 61 patients with a clinical diagnosis of either non-syndromic RP (n = 30) or Usher syndrome type 2 (USH2; n = 31) who were demonstrated to carry biallelic pathogenic variants in USH2A in a three-year period. Genetic screening was performed either by gene panel sequencing or by exome sequencing. A total of 72 available first- or second-degree relatives were also genotyped for familial segregation of the identified variants. Results: The USH2A mutational spectrum in RP patients included 39 distinct pathogenic variants, most of them of the missense type. The most common RP-causing variants were p.Cys759Phe (c.2276G>T), p.Glu767Serfs*21 (c.2299delG), and p.Cys319Tyr (c.956G>A), which together accounted for 25% of all RP variants. Novel USH2A mutations included three nonsense, two missense, two frameshift, and one intragenic deletion. The USH2A mutational spectrum in USH2 patients included 26 distinct pathogenic variants, most of them of the nonsense and frameshift types. The most common Usher syndrome-causing variants were p.Glu767Serfs*21 (c.2299delG), p.Arg334Trp (c.1000C>T), and c.12067-2A>G), which together accounted for 42% of all USH2-related variants. Novel Usher syndrome USH2A mutations included six nonsense, four frameshift, and two missense mutations. The c.2299delG mutation was associated with a common haplotype for SNPs located in exons 2-21 of USH2A, indicating a founder mutation effect. Conclusions: Our work expands the USH2A mutational profile by identifying 20 novel pathogenic variants causing syndromic and non-syndromic retinal dystrophy. The prevalent c.2299delG allele is shown to arise from a founder effect. Our results emphasize the usefulness of molecular screening in underrepresented populations for a better characterization of the molecular spectrum of common monogenic diseases.

Clinical-genetic findings in a group of subjects with macular dystrophies due to mutations in rare inherited retinopathy genes.

PURPOSE: To describe the results of clinical and molecular analyses in a group of patients suffering from inherited macular dystrophies, in which next-generation sequencing (NGS) efficiently detected rare causative mutations. METHODS: A total of eight unrelated Mexican subjects with a clinical and multimodal imaging diagnosis of macular dystrophy were included. Visual assessment methods included best corrected visual acuity, color fundus photography, Goldmann visual field tests, kinetic perimetry, dark/light adapted chromatic perimetry, full-field electroretinography, autofluorescence imaging, and spectral domain-optical coherence tomography imaging. Genetic screening was performed by means of whole exome sequencing with subsequent Sanger sequencing validation of causal variants. RESULTS: All patients exhibited a predominantly macular or cone-dominant disease. Patients' ages ranged from 12 to 60 years. Three cases had mutations in genes associated with autosomal dominant inheritance (UNC119 and PRPH2) while the remaining five cases had mutations in genes associated with autosomal recessive inheritance (CNGA3, POC1B, BEST1, CYP2U1, and PROM1). Of the total of 11 different pathogenic alleles identified, three were previously unreported disease-causing variants. CONCLUSIONS: Macular dystrophies can be caused by defects in genes that are not routinely analyzed or not included in NGS gene panels. In this group of patients, whole exome sequencing efficiently detected rare genetic causes of hereditary maculopathies, and our findings contribute to expanding the current knowledge of the clinical and mutational spectrum associated with these disorders.

Effectiveness of Whole-Exome Sequencing for the Identification of Causal Mutations in Patients with Suspected Inherited Ocular Diseases.

Background: Genetic eye disorders, affecting around one in 1000 people, encompass a diverse group of diseases causing severe visual deficiency. The recent adoption of next-generation sequencing techniques, including whole-exome sequencing (WES), in medicine has greatly enhanced diagnostic rates of genetically heterogeneous diseases. Objectives: The objectives of the study were to assess the diagnostic yield of WES in a cohort of Mexican individuals with suspected genetic eye disorders and to evaluate the improvement of diagnostic rates by reanalysis of WES data in patients without an initial molecular diagnosis. Methods: A total of 90 probands with ocular anomalies of suspected genetic origin were ascertained. Patients underwent WES in leukocytic DNA. Bioinformatics analysis and Sanger sequencing were used to confirm the disease-causing variants. Only variants identified as pathogenic or likely pathogenic were considered as causal. Results: Initial analysis revealed causal mutations in 46 cases (51%). Reanalysis of WES data 12 months after first analysis resulted in the identification of additional causal variants in 6 patients (7%), increasing the molecular diagnostic yield to 58%. The highest diagnostic rates by disease categories corresponded to hereditary retinal dystrophies (77%) and to anomalies of the anterior segment of the eye (47%). Conclusions: Our study demonstrates that WES is an effective approach for genetic diagnosis of genetic ocular diseases and that reanalysis of WES data can improve the diagnostic yield.

Effectiveness of Whole-Exome Sequencing for the Identification of Causal Mutations in Patients with Suspected Inherited Ocular Diseases

ABSTRACT Background: Genetic eye disorders, affecting around one in 1000 people, encompass a diverse group of diseases causing severe visual deficiency. The recent adoption of next-generation sequencing techniques, including whole-exome sequencing (WES), in medicine has greatly enhanced diagnostic rates of genetically heterogeneous diseases. Objectives: The objectives of the study were to assess the diagnostic yield of WES in a cohort of Mexican individuals with suspected genetic eye disorders and to evaluate the improvement of diagnostic rates by reanalysis of WES data in patients without an initial molecular diagnosis. Methods: A total of 90 probands with ocular anomalies of suspected genetic origin were ascertained. Patients underwent WES in leukocytic DNA. Bioinformatics analysis and Sanger sequencing were used to confirm the disease-causing variants. Only variants identified as pathogenic or likely pathogenic were considered as causal. Results: Initial analysis revealed causal mutations in 46 cases (51%). Reanalysis of WES data 12 months after first analysis resulted in the identification of additional causal variants in 6 patients (7%), increasing the molecular diagnostic yield to 58%. The highest diagnostic rates by disease categories corresponded to hereditary retinal dystrophies (77%) and to anomalies of the anterior segment of the eye (47%). Conclusion: Our study demonstrates that WES is an effective approach for genetic diagnosis of genetic ocular diseases and that reanalysis of WES data can improve the diagnostic yield.

Detailed phenotypic description of stromal corneal dystrophy in a large pedigree carrying the uncommon TGFBI p.Ala546Asp pathogenic variant.

PURPOSE: The purpose of this study is to describe the corneal clinical spectrum and the intrafamilial phenotypic differences in an extended pedigree suffering from stromal corneal dystrophy due to the rare p.Ala546Asp mutation in TGFBI. METHODS: A total of 15 members from a four-generation Mexican family were ascertained for clinical and genetic assessment. All individuals underwent slit-lamp biomicroscopic examination and an extensive ophthalmological examination including corneal topography (OCULUS Pentacam® AXL), corneal biomechanics (OCULUS Corvis ST), and corneal confocal biomicroscopy (Heidelberg Engineering®). A total of 10 individuals carried the heterozygous c.1637C>A (p. Ala546Asp) mutation at TGFBI exon 12. RESULTS: Nine out of 10 mutation positive patients were available for clinical characterization. The mean age was 35.5 years, with the youngest and the eldest ones being 3 years old and 62 years old, respectively. The median age of onset of the symptoms was 19.7 years. Five (55.6%) patients presented with a predominantly granular corneal dystrophy type 2 (GCD2) phenotype, one presented with a lattice corneal dystrophy (LCD) phenotype, and one with a granular corneal dystrophy type 1 (GCD1) phenotype. Interestingly, two mutation positive subjects had no clinical deposits in the cornea, demonstrating incomplete penetrance of the disorder in this family. CONCLUSIONS: Clinical differences in corneal phenotypes within this CD family and with other pedigrees carrying the same TGFBI genetic defect could be explained by the age of clinical examination of individual patients and/or by the presence of genetic and/or environmental modifiers.

A new missense variant in RAB3GAP2 in a family with muscular dystrophy-short stature and defective autophagy: An expansion of the micro/Martsolf spectrum or a new phenotype?

We describe a sibling pair of Mennonite origin born from consanguineous parentage with a likely new phenotype of limb-girdle muscular dystrophy, short stature, ptosis, and tracheomalacia. Exome sequencing in the affected subjects identified a novel homozygous RAB3GAP2 missense variant as the potential causal variant. As RAB3GAP2 has been recently shown to be involved in the autophagy process, we analyzed patient-derived fibroblasts by fluorescence microscopy and demonstrated defective autophagic flux under rapamycin and serum starvation conditions when compared with wild-type cells. The phenotype in the siblings described here is distinct from Martsolf and Warburg's micro syndromes, the currently known diseases arising from RAB3GAP2 pathogenic variants. Thus, this work describes a potentially novel recessive phenotype associated with a RAB3GAP2 defect and manifesting as a muscular dystrophy-short stature disorder with no ocular anomalies. Functional analyses indicated defective autophagy in patient-derived fibroblasts, supporting the involvement of RAB3GAP2 in the etiology of this disorder. Our results contribute to a better characterization of the Martsolf/micro spectrum phenotype.

AUTOSOMAL DOMINANT MÜLLER CELL SHEEN DYSTROPHY: Clinical, Histopathologic, and Genetic Assessment in an Extended Family With Long Follow-Up.

BACKGROUND: Autosomal dominant Müller cell dystrophy is a rare condition we described in 1991. It is characterized by a striking sheen appearance on the retinal surface with progressive retinal changes leading to disorganization and atrophy with a decreased b-wave electroretinograms. MATERIALS AND METHODS: We examined 45 members of a 4-generation family. Fifteen subjects from three generations were found with the disease, without gender predilection. Seven patients underwent ophthalmic examination including fundus examination, intravenous fluorescein angiogram, spectral-domain optical coherence tomography, and electroretinogram. Six patients have a 30-year follow-up. Histopathology examination was performed on eyes of the eldest patient. Whole exome sequencing was done in four affected subjects. RESULTS: Findings include a decreased visual acuity, abnormal cellophane-like sheen of the vitreoretinal interface, a "plush" nerve fiber layer, and characteristic macular changes. Electroretinogram showed a selective b-wave diminution. Intravenous fluorescein angiogram presented perifoveal hyperfluorescence and capillary leakage. Spectral-domain optical coherence tomography revealed cavitations involving inner and later outer retinal layers with later disorganization. Histopathologic findings included Müller cell abnormalities with cystic disruption of inner retinal layers, pseudoexfoliation in anterior segment, and amyloidosis of extraocular vessels. Pedigree analysis suggests an autosomal dominant inheritance with late onset. DNA analysis demonstrated a previously undescribed heterozygous missense p.Glu109Val mutation in transthyretin. CONCLUSION: To the best of our knowledge, this is the first family reported with this disorder. Our data support the hypothesis that autosomal dominant Müller cell dystrophy is a distinct retinal dystrophy affecting Müller cells. Mutations in transthyretin gene may manifest as a predominantly retinal disorder.

Contribution of APOA5, APOC3, CETP, ABCA1 and SIK3 genetic variants to hypertriglyceridemia development in Mexican HIV-patients receiving antiretroviral therapy.

OBJECTIVE: To investigate the impact of single nucleotide polymorphisms (SNPs) from APOA5, APOC3, CETP, ATP binding cassette transporter A1 and SIK3 genes in the development of hypertriglyceridemia in HIV patients under antiretroviral therapy. MATERIAL AND METHODS: A case-control study was developed. Leukocytic genomic DNA was extracted and genotyping for SNPs rs662799, rs964184, rs5128, rs2854116, rs2854117, rs3764261, rs4149310, rs4149267 and rs139961185 was performed by real time-PCR using TaqMan allelic discrimination assays, in Mexican mestizo patients with HIV infection, with hypertriglyceridemia (>1.7 mmol/L) under antiretroviral therapy. Genetic variants were also investigated in a control group of normolipidemic HIV patients (≤ 1.7 mmol/L). Haplotypes and gene interactions were analyzed. RESULTS: A total of 602 HIV patients were genotyped (316 cases and 286 controls). Age and antiretroviral regimen based on protease inhibitors were associated with hypertriglyceridemia (P = 0.0001 and P = 0.0002. respectively). SNP rs964184 GG genotype in APOA5 gene exhibited the highest association with hypertriglyceridemia risk (OR, 3.2, 95% CI, 1.7-5.8, P = 0.0001); followed by SNP rs139961185 in SIK3 gene (OR = 2.3; (95% CI, 1.1-4.8; P = 0.03 for AA vs. AG genotype; and APOC3 rs5128 GG genotype, (OR, 2.2; 95% CI, 1.1-4.9; P = 0.04) under codominant models. These associations were maintained in the adjusted analysis by age and protease inhibitors based antiretroviral regimens. CONCLUSIONS: This study reveals an association between rs964184 in APOA5; rs5128 in APOC3 and rs139961185 in SIK3 and high triglyceride concentrations in Mexican HIV-patients receiving protease inhibitors. These genetic factors may influence the adverse effects related to antiretroviral therapy.

Next-Generation Sequencing Identifies a Homozygous Nonsense p.Tyr370* Mutation of the TMC6 Gene in a Mexican Pedigree with Epidermodysplasia Verruciformis.

Epidermodysplasia verruciformis (EV) is a rare genodermatosis characterized by abnormal susceptibility to infection with b-genotype human papillomavirus (HPV) and a particular propensity to develop cutaneous malignancies. Clinical manifestations include flat, scaly, reddish hypo- and hyperpigmented macules, verruca-like papillomatous lesions, seborrheic keratosis- like lesions, and pink-red pityriasis versicolor-like lesions1.

Clinical, histopathological, and in silico pathogenicity analyses in a pedigree with familial amyloidosis of the Finnish type (Meretoja syndrome) caused by a novel gelsolin mutation.

Purpose: Familial amyloidosis of the Finnish type (FAF) is an inherited amyloidosis arising from mutations in the gelsolin protein (GSN). The disease includes facial paralysis, loose skin, and lattice corneal dystrophy. To date, FAF has been invariably associated with substitution of Asp214 in GSN. We describe the clinical, histopathological, and genetic features of a family with FAF due to a novel GSN mutation. Methods: Five affected adult individuals in a three-generation FAF pedigree were included in the study. Histopathological analysis was performed on an eyelid skin biopsy from one patient. Genetic analysis included next-generation sequencing (NGS) and Sanger sequencing for confirmation of the GSN variant. Several tools for in silico analysis of pathogenicity for the novel variant and to predict the effect of the amino acid replacement on protein stability were used. Results: Three older adult affected patients exhibited corneal lattice dystrophy, cutis laxa, and facultative peripheral neuropathy. Two younger adult individuals presented only with corneal amyloid deposits. NGS identified a heterozygous GSN c.1631T>G transversion, predicting a novel p.Met544Arg mutation. All in silico tools indicated that p.Met544Arg is deleterious for GSN functionality or stability. Conclusions: The results expand the molecular spectrum of GSN-linked systemic amyloidosis. The novel p.Met544Arg pathogenic variant is predicted to affect gelsolin function, presumably by impairing a potential calcium-sensitive, actin-binding region.