Molecular study of hearing loss in Minas Gerais, Brazil / Estudo molecular da perda auditiva em Minas Gerais, Brasil

Abstract Introduction: Deafness is the most frequent sensory deficit in humans. Incidence is estimated at 4:1000 births in Brazil. Specific programs for clinical care of patients with hearing loss are still scarce in Brazil and the issue is an important public health problem. Objective: To determine the frequency of 35delG and D13S1830 mutations in GJB2 and GJB6 genes respectively in patients with non-syndromic sensorineural hearing loss from Minas Gerais, Brazil. Methods: This research involved 53 individuals, who were assessed by a questionnaire for predicting the possibility of non-syndromic deafness and for data collecting. Samples were tested for the presence of the 35delG mutation in GJB2 gene and D13S1830 in GJB6 gene by polymerase chain reaction and restriction enzyme digestion. Results: Epidemiological research has shown that the majority of the subjects are unaware of the etiology and the pathogenesis of hearing loss. In 9 patients (16.98%), 35delG mutation was found in heterozygosis and the allele frequency was estimate to be around 8.5%. Although 9.61% of the patients reported having some degree of consanguinity between the parents and 12.08% reported other cases of deafness in their families, this mutation was not found in homozygosis. The D13S1830 mutation was not found in this study. Conclusion: This research describes for the first time the frequency of the 35delG and D13S1830 mutation in hearing-impaired individuals from Minas Gerais, Brazil, and the collected data reinforce the need for further studies in this population due to heterogeneity of hearing loss.

Resumo Introdução: A surdez é o déficit sensorial mais frequente em humanos. Estima-se que a incidência seja de 4:1.000 nascimentos no Brasil. Programas específicos para atendimento clínico de pacientes com perda auditiva são escassos no Brasil e a questão é um importante problema de saúde pública. Objetivo: Determinar a frequência das mutações 35delG no gene GJB2 e D13S1830 no GJB6 em pacientes deficientes auditivos de origem neurossensorial e não sindrômica de Minas Gerais, Brasil. Método: A pesquisa envolveu 53 indivíduos selecionados por meio de questionário o qual avaliou a possibilidade de surdez não sindrômica entre outros dados. As amostras foram testadas quanto à presença da mutação 35delG no gene GJB2 e D13S1830 no gene GJB6 por reação em cadeia da polimerase e digestão com enzima de restrição. Resultados: A pesquisa epidemiológica mostrou que a maioria dos indivíduos desconhece a etiologia da perda auditiva. Em 9 pacientes (16,98%), a mutação 35delG foi encontrada em heterozigose e a frequência alélica foi estimada em 8,5%. Embora 9,61% das pessoas tenham relatado algum grau de consanguinidade entre os pais e 12,08% relatassem outros casos de surdez em suas famílias, essa mutação não foi encontrada em homozigose. A mutação D13S1830 não foi encontrada neste estudo. Conclusão: Este trabalho descreve pela primeira vez a frequência da mutação 35delG e D13S1830 em deficientes auditivos de Minas Gerais, Brasil, e os dados coletados reforçam a necessidade de mais estudos nessa população devido à heterogeneidade da perda auditiva.

Molecular study of hearing loss in Minas Gerais, Brazil.

INTRODUCTION: Deafness is the most frequent sensory deficit in humans. Incidence is estimated at 4:1000 births in Brazil. Specific programs for clinical care of patients with hearing loss are still scarce in Brazil and the issue is an important public health problem. OBJECTIVE: To determine the frequency of 35delG and D13S1830 mutations in GJB2 and GJB6 genes respectively in patients with non-syndromic sensorineural hearing loss from Minas Gerais, Brazil. METHODS: This research involved 53 individuals, who were assessed by a questionnaire for predicting the possibility of non-syndromic deafness and for data collecting. Samples were tested for the presence of the 35delG mutation in GJB2 gene and D13S1830 in GJB6 gene by polymerase chain reaction and restriction enzyme digestion. RESULTS: Epidemiological research has shown that the majority of the subjects are unaware of the etiology and the pathogenesis of hearing loss. In 9 patients (16.98%), 35delG mutation was found in heterozygosis and the allele frequency was estimate to be around 8.5%. Although 9.61% of the patients reported having some degree of consanguinity between the parents and 12.08% reported other cases of deafness in their families, this mutation was not found in homozygosis. The D13S1830 mutation was not found in this study. CONCLUSION: This research describes for the first time the frequency of the 35delG and D13S1830 mutation in hearing-impaired individuals from Minas Gerais, Brazil, and the collected data reinforce the need for further studies in this population due to heterogeneity of hearing loss.

Prevalence of polymorphisms in the ANKK1, DRD2, DRD3 genes and metabolic syndrome in refractory schizophrenia.

OBJECTIVE: to estimate the prevalence of TaqIA, -141C and rs6280 polymorphisms of the ANKK1, DRD2 and DRD3 genes and evaluate their association with the occurrence of metabolic syndrome in patients with refractory schizophrenia. METHOD: cross-sectional study conducted in the Extended Western Region of Minas Gerais, with refractory schizophrenic patients using the antipsychotic clozapine. Sociodemographic, clinical, anthropometric, biochemical and genetic data were collected. Univariate analysis of the data was performed. RESULTS: seventy-two patients participated in the study and the occurrence of Metabolic Syndrome was observed in 47.2% of them. There was no association between Metabolic Syndrome and the studied polymorphisms. There was a statistically significant difference in the low HDL parameter with homozygous genotype for the C allele of the -141C polymorphism of the DRD2 gene. CONCLUSION: a high prevalence of MS was evidenced. The -141C polymorphism was associated with low HDL. Genetic analysis and identification of metabolic alterations in this group of patients can guide drug treatment and provide a better quality of life.

Prevalence of polymorphisms in the ANKK1, DRD2, DRD3 genes and metabolic syndrome in refractory schizophrenia / Prevalência de polimorfismos nos genes ANKK1, DRD2, DRD3 e síndrome metabólica na esquizofrenia refratária / Prevalencia de polimorfismos en los genes ANKK1, DRD2, DRD3 y síndrome metabólico en la esquizofrenia refractária

ABSTRACT Objective: to estimate the prevalence of TaqIA, -141C and rs6280 polymorphisms of the ANKK1, DRD2 and DRD3 genes and evaluate their association with the occurrence of metabolic syndrome in patients with refractory schizophrenia. Method: cross-sectional study conducted in the Extended Western Region of Minas Gerais, with refractory schizophrenic patients using the antipsychotic clozapine. Sociodemographic, clinical, anthropometric, biochemical and genetic data were collected. Univariate analysis of the data was performed. Results: seventy-two patients participated in the study and the occurrence of Metabolic Syndrome was observed in 47.2% of them. There was no association between Metabolic Syndrome and the studied polymorphisms. There was a statistically significant difference in the low HDL parameter with homozygous genotype for the C allele of the -141C polymorphism of the DRD2 gene. Conclusion: a high prevalence of MS was evidenced. The -141C polymorphism was associated with low HDL. Genetic analysis and identification of metabolic alterations in this group of patients can guide drug treatment and provide a better quality of life.

RESUMO Objetivo: estimar a prevalência dos polimorfismos TaqIA, -141C e rs6280 dos genes ANKK1, DRD2 e DRD3 e avaliar sua associação com a ocorrência de síndrome metabólica em pacientes com esquizofrenia refratária. Método: estudo de delineamento transversal, realizado na Região Ampliada Oeste de Minas Gerais, que incluiu pacientes com esquizofrenia refratária em uso do antipsicótico clozapina. Foram coletados dados sociodemográficos, clínicos, antropométricos, bioquímicos e genéticos. Realizou-se análise univariada dos dados. Resultados: participaram 72 pacientes e observou-se a ocorrência de Síndrome Metabólica em 47,2%, não sendo encontrada associação da Síndrome Metabólica com os polimorfismos estudados. Houve diferença estatisticamente significante com o parâmetro do baixo HDL com genótipo homozigoto para alelo C do polimorfismo -141C do gene DRD2. Conclusão: evidenciou-se prevalência de SM elevada. O polimorfismo -141C associou-se ao baixo HDL. A análise genética e a identificação de alterações metabólicas, neste grupo de pacientes, podem nortear o tratamento medicamentoso e propiciar melhor qualidade de vida.

RESUMEN Objetivo: estimar la prevalencia de los polimorfismos TaqIA, -141C y rs6280 de los genes ANKK1, DRD2 y DRD3 y evaluar su asociación con el síndrome metabólico en pacientes con esquizofrenia refractária. Método: estudio de delineamiento transversal, realizado en la Región Ampliada Oeste de Minas Gerais, que incluye pacientes con esquizofrenia refractária usando el antipsicótico clozapina. Fueron recogidos datos sociodemográficos, clínicos, antropométricos, bioquímicos y genéticos. Se realizó um análisis univariada de los datos. Resultados: participaron 72 pacientes y se observó el Síndrome Metabólico en 47,2%, no siendo encontrada una asociación del Síndrome Metabólico con los polimorfismos estudiados. Hubo diferencia estadísticamente significante con el parámetro del bajo HDL con genotipo homozigoto para alelo C del polimorfismo -141C del gen DRD2. Conclusión: se vio una prevalencia de SM elevada. El polimorfismo -141C se asoció al bajo HDL. El análisis genético y la identificación de alteraciones metabólicas, en este grupo de pacientes, pueden guiar al tratamiento medicamentoso y propiciar mejor calidad de vida.

Ocorrência de esquistossomose em Divinópolis-MG baseada em estudo com escolares e em inquéritos de notificação da doença / Occurrence of schistosomiasis in Divinópolis-MG based on study of schoolchildren and surveys of disease notification

Introduction: Schistosomiasis is a neglected chronic disease that affects mainly underdeveloped regions, including Brazil. Objective: To evaluate the distribution profile of the schistosomiasis in Divinópolis-MG. Material and methods: It is characterized as a descriptive and analytical epidemiological study. A parasitological study performed in schoolchildren of public municipal schools; simultaneously, a survey of schistosomiasis cases reported in the city between 2005 and 2011 years was performed with the Municipal Department of Health. Data related to the characteristics of the infection were observed, such as: affected areas, age, gender, and professional occupation. Results: This survey showed 33 cases of schistosomiasis in the city during this period, which the most of them (84.8%) were between 20-59 years of age. The results of the study with the schoolchildren are in agreement with those obtained through the reporting forms, both indicating no occurrence of schistosomiasis in individuals between 6-14 years of age in Divinópolis. Conclusion: The absence of the disease in children and adolescents analyzed and the presence in adults is a strong evidence of exogenous contamination in the city, especially as a result of immigration or rural tourism, and possible changes in habits, related to risk factors...

Introdução: A esquistossomose é uma doença crônica negligenciada, que afeta principalmente regiões subdesenvolvidas, incluindo o Brasil. Objetivo: Avaliar o perfil de distribuição da esquistossomose na região de Divinópolis-MG. Material e métodos: Caracteriza-se como um estudo epidemiológico analítico e descritivo. Foi realizado um estudo parasitológico em escolares da rede pública municipal e, concomitantemente, realizou-se também um levantamento dos casos notificados da doença no município entre 2005 e 2011, junto à Secretaria Municipal de Saúde. Foram verificados dados relacionados com as características da infecção, como regiões afetadas, faixa etária, gênero e ocupação profissional. Resultados: O levantamento apontou 33 casos de esquistossomose no município neste período, sendo a maior parte deles (84,8%) na faixa etária de 20 a 59 anos. Os resultados do estudo com os escolares estão em concordância com os obtidos por meio das fichas de notificação, ambos indicando a não ocorrência de esquistossomose em indivíduos de 6 a 14 anos em Divinópolis. Conclusão: A ausência da doença nas crianças e nos adolescentes analisados e a presença em adultos sugerem forte evidência de contaminação exógena no município, especialmente fruto de imigração ou turismo rural, além de possíveis mudanças de hábitos, relacionados com os fatores de risco...

Trombofilias: a prevenção direcionada a uma gravidez bem-sucedida / Thrombophilia: prevention targeted to a successful pregnancy

Vários efeitos adversos na gravidez, como pré-eclampsia, deslocamento de placenta, prematuridade e até mesmo perdas fetais recorrentes vêm sendo amplamente associados a estados trombofílicos. Uma vez que o número de trombofilias herdadas tem crescido rapidamente nos últimos anos com a identificação de vários fatores genéticos predispondo ao desenvolvimento de trombose venosa ou arterial, cada vez mais se torna de grande interesse a identificação de mulheres de risco, na tentativa de minimizar os problemas na gravidez e, principalmente, instituir regimes terapêuticos para a prevenção de perdas fetais. Esta revisão aborda os riscos associados à presença de alterações genéticas predispondo à trombose e a importância de um monitoramento adequado.

Many adverse effects during pregnancy, like preeclampsia, placental abruptions, prematurity and recurrent fetal loss have been widely associated with thrombophilic states. The number of inherited thrombophilias has grown rapidly in recent years with the identification of many predisponent genetic factors to the development of venous and/or arterial thrombosis. Therefore, the identification of women of risk becomes of great interest in the attempt to minimize the problems during pregnancy and mainly to institute therapeutical regimens for fetal loss prevention. This review approaches the risk associated to the presence of genetic alterations predisposing to thrombosis, and the importance of an adequate follow up.

Frequencies of phenylalanine hydroxylase mutations I65T, R252W, R261Q, R261X, IVS10nt11, V388M, R408W, Y414C, and IVS12nt1 in Minas Gerais, Brazil.

In order to determine the phenylketonuria (PKU) mutation spectrum in the population of Minas Gerais State, Brazil, 78 unrelated PKU patients found by the neonatal screening program from 1993 to 2003 were tested for nine phenylalanine hydroxylase mutations. These mutations were selected due to their high frequencies in other Brazilian populations and in Portugal, where the largest contingent of the Caucasian component of the Brazilian population originated from. The most frequent mutations were V388M (21%), R261Q (16%), IVS10nt11 (13.4%), I65T (5.7%), and R252W (5%). The frequencies of the other four mutations (R261X, R408W, Y414C, and IVS12nt1) did not reach 2%. By testing these nine mutations, we were able to identify 64% of the PKU alleles in our sample. V388M frequency was higher than in any other known population and almost three times larger than that observed in Portugal, probably reflecting genetic drift. The mutation profile, as well as the relative frequency of the different mutations, suggest that the Minas Gerais population more closely resembles that of Portugal than do the other Brazilian populations that have already been tested.

The time has come: a new scene for PKU treatment.

Phenylketonuria (PKU) is one of the few genetic diseases in which mental retardation can be prevented. Hence, diagnosis and treatment must be established early. PKU treatment consists of a phenylalanine-restricted diet supplemented with a phenylalanine-free mixture of amino acids. However, it is difficult to adhere to this diet. In the last decade, a better comprehension of the biochemistry, genetics and molecular basis of the disease, as well as the need for easier treatment, led to the development of several new therapeutic strategies for PKU. In the present study, we evaluated these new therapeutic options in terms of theoretical basis, methodologies, efficacy, and costs.