Karita Antunes Costa

Human Leukocyte Antigen Class I Genes Associated With Stevens-Johnson Syndrome and Severe Ocular Complications Following Use of Cold Medicine in a Brazilian Population

Importance Describing the association with human leukocyte antigen (HLA) alleles could facilitate the understanding of increased risk factors for development of Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) in patients with severe ocular complications (SOCs). Objective To investigate the association between HLA class I genes and cold medicine (CM)–associated SJS/TEN with SOCs. Design, Setting, and Participants This case-control study was conducted between February 8, 2013, and August 29, 2014. Thirty-nine Brazilian patients with CM-SJS/TEN of 74 patients with SJS/TEN with SOCs and 133 healthy Brazilian volunteers were enrolled. Human leukocyte antigen class I genes (HLA-A, HLA-B, and HLA-C) were examined to determine whether there was a genetic predisposition for CM-SJS/TEN with SOC. Patients were interviewed to identify possible etiologic factors. Data analysis was performed from April 14, 2013, to August 29, 2014. Main Outcomes and Measures Genetic predisposition for CM-SJS/TEN with SOCs by analysis of HLA class I genes. Results Of 74 patients included in the analysis, 32 (43%) were male; mean (SD) age was 36.01 [15.42] years. HLA-A*66:01 (odds ratio [OR], 24.0; 95% CI, 2.79-206.0; P < .001), HLA-B*44:03 (OR, 2.71; 95% CI, 1.11-6.65; P = .04), and HLA-C*12:03 (OR, 5.6; 95% CI, 1.67-18.80; P = .006) were associated with Brazilian CM-SJS/TEN with SOCs, and HLA-A*11:01 (OR, 0.074; 95% CI, 0.004-1.26; P = .008), HLA-B*08:01 (OR, 0.15; 95% CI, 0.02-1.15; P = .048), and HLA-B*51:01 (OR, 0.23; 95% CI, 0.05-1.03; P = .045) were inversely associated with Brazilian CM-SJS/TEN with SOCs (39 cases: 19 Pardo and 16 European ancestry; 14 males and 25 females; age, 35.2 [14.4] years; and 133 controls: 66 Pardo and 61 European ancestry; 55 males and 78 females; age, 41.2 [12.9] years). When multiple test correction within the HLA locus, HLA-A*66:01 and HLA-C*12:03 demonstrated associations. When participants were segregated into Pardo and locus is considered, HLA-A*66:01 was associated with CM-SJS/TEN with SOC among individuals of both ethnic groups (Pardo: OR, 12.2; 95% CI, 1.19-125.0; P = .03; and European: OR, 21.2; 95% CI, 0.97-465.0; P = .04). An association was observed only in the European cohort for HLA-B*44:03 (OR, 5.50; 95% CI, 1.47-20.50; P = .01) and HLA-C*12:03 (OR, 8.79; 95% CI, 1.83-42.20; P = .008). Conclusions and Relevance This study suggests that HLA-A*66:01 might be a marker for CM-SJS/TEN with SOCs in Brazilian individuals of Pardo and European ancestry and that HLA-B*44:03 and HLA-C*12:03 might be markers only in those of European ancestry. Moreover, HLA-A*11:01 might be a marker of resistance to CM-SJS/TEN with SOCs.

Genotype-Phenotype Correlations in CYP1B1-Associated Primary Congenital Glaucoma Patients Representing Two Large Cohorts from India and Brazil.

Background Primary congenital glaucoma (PCG), occurs due to the developmental defects in the trabecular meshwork and anterior chamber angle in children. PCG exhibits genetic heterogeneity and the CYP1B1 gene has been widely implicated worldwide. Despite the diverse mutation spectra, the clinical implications of these mutations are yet unclear. The present study attempted to delineate the clinical profile of PCG in the background of CYP1B1 mutations from a large cohort of 901 subjects from India (n=601) and Brazil (n=300). Methods Genotype-phenotype correlations was undertaken on clinically well characterized PCG cases from India (n=301) and Brazil (n=150) to assess the contributions of CYP1B1 mutation on a set of demographic and clinical parameters. The demographic (gender, and history of consanguinity) and quantitative clinical (presenting intraocular pressure [IOP] and corneal diameter [CD]) parameters were considered as binary and continuous variables, respectively, for PCG patients in the background of the overall mutation spectra and also with respect to the prevalent mutations in India (R368H) and Brazil (4340delG). All these variables were fitted in a multivariate logistic regression model using the Akaike Information Criterion (AIC) to estimate the adjusted odds ratio (OR) using the R software (version 2.14.1). Results The overall mutation spectrum were similar across the Indian and Brazilian PCG cases, despite significantly higher number of homozygous mutations in the former (p=0.024) and compound heterozygous mutations in the later (p=0.012). A wide allelic heterogeneity was observed and only 6 mutations were infrequently shared between these two populations. The adjusted ORs for the binary (demographic) and continuous (clinical) variables did not indicate any susceptibility to the observed mutations (p>0.05). Conclusions The present study demonstrated a lack of genotype-phenotype correlation of the demographic and clinical traits to CYP1B1 mutations in PCG at presentation. However, the susceptibility of these mutations to the long-term progression of these traits are yet to be deciphered.

The correlation between CRB1 variants and the clinical severity of Brazilian patients with different inherited retinal dystrophy phenotypes

Inherited retinal dystrophies are characterized by progressive retina degeneration and mutations in at least 250 genes have been associated as disease-causing. CRB1 is one of many genes analyzed in molecular diagnosis for inherited retinal dystrophy. Crumbs homolog-1 protein encoded by CRB1 is important for cell-to-cell contact, polarization of epithelial cells and the morphogenesis of photoreceptors. Pathogenic variants in CRB1 lead to a huge variety of phenotypes ranging from milder forms of inherited retinal dystrophy, such as retinitis pigmentosa to more severe phenotypes such as Leber congenital amaurosis. In this study, seven novel likely-pathogenic variants were identified: four missense variants (p.Leu479Pro, p.Ala921Pro, p.Cys948Arg and p.Asp1031Asn), two frameshift deletions (c.2536_2542del7 and c.3460_3461delTG) and one frameshift indel variant (c.276_294delinsTGAACACTGTAC). Furthermore, two patients with cone-rod dystrophy due to mutations in CRB1 were reported, supporting previous data, in which mutations in CRB1 can also cause cone-rod dystrophy. Finally, our data suggested there was a direct relation between phenotype severity and the mutation effect on protein functionality in 15 Brazilian CRB1 patients.

Novel Complex ABCA4 Alleles in Brazilian Patients With Stargardt Disease: Genotype-Phenotype Correlation

Purpose To analyze the presence of complex alleles of the ABCA4 gene in Brazilian patients with Stargardt disease and to assess the correlation with clinical features. Methods This was an observational cross-sectional study. Patients with a diagnosis of Stargardt disease who presented three pathogenic variants of the ABCA4 gene or who had variants previously described as complex alleles were included. The relatives of these probands were evaluated in the segregation analysis. The patients were evaluated based on age at symptom onset and visual acuity, and the clinical characteristics were classified according to the findings observed on autofluorescence examination. Results Among the 47 families analyzed, approximately 30% (14/47) presented complex alleles. The segregation analysis in 14 families with cases of Stargardt disease identified three novel complex alleles and one previously described complex allele. The known complex allele p.[Leu541Pro; Ala1038Val] was identified in two families. The novel complex alleles identified were p.[Leu541Pro; Arg1443His] in five families, p.[Ser1642Arg; Val1682_Val1686del] in seven families, and p.[Pro1761Arg; Arg2106Cys] in one family. Furthermore, four new variants (p.Lys22Asn, p.Asp915Asn, p.Glu1447Val, and p.Pro1761Arg) were identified in the second allele of the ABCA4 gene. Conclusions Segregation analysis is important in order to confirm the molecular diagnosis of patients with Stargardt disease, given the frequency of complex alleles in the ABCA4 gene. The various pathogenic variation combinations observed in this study were associated with different phenotypes.

PROM1 gene variations in Brazilian patients with macular dystrophy.

ABSTRACT Background: Although the pathogenicity of the prominin-1 (PROM1) gene has already been described as associated with autosomal dominant Stargardt disease, little is known about sequence variations in this gene. Purpose: The aim of this study was to evaluate PROM1 gene sequence variations in patients with macular dystrophy. Material and methods: This retrospective study evaluated variations in the PROM1 gene detected by next-generation sequencing test in patients with macular dystrophy and Stargardt disease. Results: Of 25 medical records of patients with Stargardt disease, three records of patients with PROM1 gene sequence variations were selected for the study. The p.Asp776Val and p.Asp829Asn variants were detected in cases 1 and 2, respectively, and predicted to be pathogenic; they were probably responsible for macular dystrophy in these patients. Case 3 showed a p.Ala643Gly variant in the PROM1 gene and a single variation in the ABCA4 gene, but molecular testing results were inconclusive. Conclusions: In cases of Stargardt disease, where molecular testing results are inconclusive for pathogenic variations in the ABCA4 gene, variations in the PROM1 gene may occur and be considered responsible for the disease in the molecular analysis. This study described three cases in which variations in PROM1 gene may play a role in the pathogenesis of macular dystrophy or be associated with both autosomal recessive and autosomal dominant inheritance.

Gene panel sequencing in Brazilian patients with retinitis pigmentosa

BackgroundRetinal dystrophies constitute a group of diseases characterized by clinical variability and pronounced genetic heterogeneity. Retinitis pigmentosa is the most common subtype of hereditary retinal dystrophy and is characterized by a progressive loss of peripheral field vision (Tunnel Vision), eventual loss of central vision, and progressive night blindness. The characteristics of the fundus changes include bone-spicule formations, attenuated blood vessels, reduced and/or abnormal electroretinograms, changes in structure imaged by optical coherence tomography, and subjective changes in visual function. The different syndromic and nonsyndromic forms of retinal dystrophies can be attributed to mutations in more than 250 genes. Molecular diagnosis for patients with retinitis pigmentosa has been hampered by extreme genetic and clinical heterogeneity between retinitis pigmentosa and other forms of retinal dystrophies. Next generation sequencing (NGS) technologies are among the most promising techniques to identify pathogenic variations in retinal dystrophies.PurposeThe purpose of this study was to discover the molecular diagnosis for Brazilian patients clinically diagnosed with a retinitis pigmentosa pattern of inheritance by using NGS technologies.Materials and methodsSixteen patients with the clinical diagnosis of retinitis pigmentosa were included in the study. Their DNA was sequenced in a panel with 132 genes related to retinal dystrophies using the Illumina® platform. Sequence analysis and variation calling was performed using Soft Genetics®, NextGene, and Geneticist Assistant software. The criteria for pathogenicity analysis were established according to the results of prediction programs (Polyphen 2, Mutation taster and MetaCore™) and comparison of pathogenic variations found with databases.ResultsThe identified potentially pathogenic variations were all confirmed by Sanger sequencing. There were 89 variations predicted as pathogenic, but only 10 of them supported the conclusion of the molecular diagnosis. Five of the nine patients were autosomal dominant RP (56%), two (22%) were autosomal recessive RP, and two (22%) were X-linked RP. Nine of the 16 patients (56%) had probably positive or positive results.ConclusionThe Next Generation Sequencing used in this study allowed the molecular diagnosis to be confirmed in 56% of the patients and clarified the inheritance pattern of the patient’s retinal dystrophies.