Molecular and immunohistochemical analyses of uveal melanoma patient cohort.

Uveal melanoma is a rare form of melanoma and the most frequent primary eye malignancy in adults. The major molecular alterations underlying uveal melanoma pathogenesis affect mainly the GNAQ, GNA11, SF3B1, and BAP1 genes. In this study, we somatically genotyped 31 Brazilian uveal melanomas for BRAF, GNA11, GNAQ, SF3B1, and BAP1 gene mutations and assessed BRCA2 and p53 protein expression. GNAQ and GNA11 mutations were detected in 60%, and SF3B1 mutation rate was 30%. p53 Immunostaining was markedly positive in 5/31, and 3/31 samples showed negative BRCA2 expression. This study supports the importance of these key genes in uveal melanoma tumorigenesis; p53 and BRCA pathways seem to play a role in a subset of patients, possibly heralding unfavorable prognosis.

Association of angiotensin type 2 receptor gene polymorphisms with ureteropelvic junction obstruction in Brazilian patients.

AIM: The angiotensin type 2 (AT2 ) receptor takes part in the process of ureteric bud during kidney development. Therefore, the gene encoding AT2 receptor, the AGTR2 gene located in the X chromosome, is a potential candidate for genetic association with Congenital Anomalies of the Kidney and Urinary Tract (CAKUT). This study aimed to investigate whether AGTR2 gene polymorphisms are associated with CAKUT in general or even with common phenotypes of CAKUT in a Brazilian sample of paediatric patients. METHODS: We analyzed 290 paediatric patients with CAKUT and 262 healthy controls from the same geographic area. TaqMan single-nucleotide polymorphism (SNP) genotyping assays for AGTR2 gene at rs1403543, rs3736556, rs35474657, rs5193 and rs5194 were performed. The sample was in Hardy-Weinberg Equilibrium for all five SNPs. RESULTS: The presence of CAKUT in general was not significantly associated with the SNPs included in this study. However, when patients were segregated according to major phenotypes, the diagnosis of Ureteropelvic Junction Obstruction (UPJO) was significantly associated with AGTR2 gene polymorphisms at rs3736556 and at rs5194. On the other hand, the diagnoses of vesicoureteral reflux and of multicystic dysplastic kidney were not associated with AGTR2 gene polymorphisms. CONCLUSION: Our results support that the AGTR2 gene may contribute to the pathogenesis of UPJO and the genetic origin of CAKUT could vary according to phenotype expression.

Association analysis of CFH and ARMS2 gene polymorphisms in a Brazilian cohort with age-related macular degeneration.

PURPOSE: To investigate the association between the CFH and ARMS2 gene polymorphisms and age-related macular degeneration (AMD) in a Brazilian cohort. METHODS: We examined 163 individuals with AMD and 154 controls recruited at the Department of Ophthalmology of the Universidade Federal de Minas Gerais, at the Instituto da Visão, and at the Centro Especializado em Olhos, in Brazil, between 2007 and 2012. Genotyping for CFH rs1061170 and ARMS2 rs10490924 single-nucleotide polymorphisms was performed. The odds ratios (OR) for all of the studied genotypes (heterozygous and homozygous) of both genes were calculated compared to homozygous ancestral alleles. RESULTS: Homozygosity for the CFH and ARMS2 at-risk allele was 33.3 and 23.6%, respectively, for AMD individuals and 10.3 and 7.1%, respectively, for controls (p < 0.0001). The OR was 7.2 (95% CI 3.6-14.5; p < 0.001) for the CFH at-risk genotype (CC) and 5.5 (95% CI 2.6-11.8; p < 0.0001) for ARMS2 (TT). Subjects homozygous for both polymorphisms had a much higher risk of developing AMD (n = 14 patients, OR 33.3, 95% CI 12.8-86.4). The proportion of ancestry in each group indicated that AMD patients had a higher European (Caucasian) component than controls. CONCLUSION: CFH and ARMS2 polymorphisms were strongly associated with AMD in this Brazilian cohort.

Application of molecular biology at the approach of Bartter's syndrome: case report.

This paper aims to show the utility of molecular biology for diagnose Bartter syndrome (BS) by the case report of two sisters and to propose a diagram for the molecular approach of this syndrome. The two reported cases presented prematurity, pregnancy complicated with polyhydramnio and low birth weight. During the first year of life, children exhibited polyuria, polydipsia and failure to thrive, leading to the investigation of renal tubular diseases and innate errors of metabolism. The laboratorial exams suggested BS, but the definitive diagnostic was only obtained by the detection of homozygous mutation on the exon 5 of the gene KCNJ1, resulting in a substitution of the aminoacid alanin for valin on codon 214 (A214V) in both DNA stripes in the two sisters and a heterozygous mutation in their parents. The definitive diagnostic of BS is frequently very difficult to be obtained. Consequently, considering the reported cases, we showed the utility of molecular techniques for the definitive diagnostic of BS and we proposed a diagram for the rational use of these techniques.

Aplicação da biologia molecular na abordagem da síndrome de Bartter: relato de caso / Application of molecular biology at the approach of Bartter's syndrome: case report

O presente trabalho teve como objetivo mostrar a utilidade da biologia molecular para o diagnóstico da síndrome de Bartter (SB) por meio do relato de caso de duas irmãs e propor um algoritmo para abordagem molecular dessa síndrome. Os dois casos relatados apresentaram prematuridade, gestação complicada com poli-hidrâmnio e baixo peso ao nascer. Durante o primeiro ano de vida, as crianças apresentaram poliúria, polidipsia e atraso no crescimento, o que levou à investigação de doenças tubulares renais e erros inatos do metabolismo. Os exames laboratoriais sugeriram SB, mas a confirmação diagnóstica só foi obtida pela detecção de mutação em homozigose no exon 5 do gene KCNJ1, resultando em substituição do aminoácido alanina por valina no códon 214 (A214V) nas duas fitas de DNA nas duas irmãs e de mutação em heterozigose em seus pais. O diagnóstico de certeza da SB muitas vezes é difícil de ser obtido. Dessa forma, por meio dos casos relatados, mostrou-se a utilidade de métodos moleculares para o diagnóstico de certeza da SB, e foi proposto um algoritmo para a utilização racional dessas técnicas.

This paper aims to show the utility of molecular biology for diagnose Bartter syndrome (BS) by the case report of two sisters and to propose a diagram for the molecular approach of this syndrome. The two reported cases presented prematurity, pregnancy complicated with polyhydramnio and low birth weight. During the first year of life, children exhibited polyuria, polydipsia and failure to thrive, leading to the investigation of renal tubular diseases and innate errors of metabolism. The laboratorial exams suggested BS, but the definitive diagnostic was only obtained by the detection of homozygous mutation on the exon 5 of the gene KCNJ1, resulting in a substitution of the aminoacid alanin for valin on codon 214 (A214V) in both DNA stripes in the two sisters and a heterozygous mutation in their parents. The definitive diagnostic of BS is frequently very difficult to be obtained. Consequently, considering the reported cases, we showed the utility of molecular techniques for the definitive diagnostic of BS and we proposed a diagram for the rational use of these techniques.