Genetic influences on Alzheimer's disease: evidence of interactions between the genes APOE, APOC1 and ACE in a sample population from the South of Brazil.

Alzheimer's disease is a complex neurodegenerative disorder. Several genes have been suggested as Alzheimer's susceptibility factors, the apolipoprotein E (APOE) gene being an established susceptibility gene and the genes coding angiotensin-converting enzyme (ACE) and apolipoprotein C1 (APOC1) being considered possible candidate genes for the disease. The objective of this study was to investigate the association of ACE and APOC1 gene polymorphisms with susceptibility to Alzheimer's disease and dementia in general, both alone and combined with the APOE gene. Forty-seven patients with dementia in general (35 of them with Alzheimer's disease) and 85 controls were investigated. The haplotypes E*3/-317*ins and E*4/-317*ins of APOE/APOC1 genes were significantly more frequent in the groups with Alzheimer's disease and dementia in general (P < 0.001). The frequency of the ACE*ins allele was also greater in the groups with Alzheimer's disease and dementia in general (P = 0.022; P = 0.045), but genotype frequencies were only different in groups without the E*4/-317*ins haplotype (P = 0.012 for Alzheimer's disease; P = 0.04 for dementia). Our data point to important genetic interactions involved in these diseases.

Interação entre qualidade do meio ambiente, estresse e a variação do gene APOE na determinação da suscetibilidade à fibromialgia / Association between environmental quality, stress and APOE gene variation in fibromyalgia susceptibility determination

INTRODUÇÃO: A fibromialgia se trata de uma desordem multifatorial, cuja etiologia reside na interação entre a susceptibilidade genética e o ambiente. No entanto, poucos trabalhos procuram detectar quais seriam os fatores considerados de risco. OBJETIVO: Investigar a influência genética e sua interação com qualidade ambiental e com estresse como possíveis fatores de risco para o desenvolvimento da fibromialgia. PACIENTES E MÉTODOS: Neste estudo transversal, foram investigados dois grupos de mulheres, sendo 47 com diagnóstico clínico de fibromialgia, e 41 mulheres do grupo controle, todas da comunidade de Novo Hamburgo, RS. O polimorfismo do gene da apolipoproteína E (APOE) foi analisado, a partir do DNA extraído do sangue total de ambas as amostras. Os fatores ambientais foram avaliados através do inventário de sintomas para adultos de Lipp (ISSL), para a averiguação do estresse comportamental, e da aplicação do domínio V do WHOQOL-100. RESULTADOS: Dentre as pacientes, foram encontradas mais mulheres com níveis altos de estresse, quando comparado à amostra controle (P < 0,001); além disto, os escores médios do domínio V do WHOQOL-100, que avalia qualidade do meio ambiente, foram inferiores neste grupo (P < 0,001). As frequências genotípicas e alélicas do gene APOE foram similares entre os dois grupos. A análise multivariada demonstrou que baixos escores do WHOQOL-100, aumentaram a chance de desenvolvimento da doença em 57,7 vezes (P < 0,001), e que altos níveis de estresse foram significativamente relacionados com a doença (OR = 197,2; P < 0,001). Essa abordagem apontou para uma interação entre estresse e a presença do alelo E*2 (P = 0,028). A doença foi muito mais frequente em pacientes com altos níveis de estresse que não eram portadoras do alelo E*2 (OR estimado = 265,1), quando comparada a pacientes com o mesmo nível de estresse e portadoras do alelo E*2 (OR estimado = 1,06). CONCLUSÃO: A presença do alelo E*2 pode indicar possível ...

INTRODUCTION: Fibromyalgia is a multifactorial disease, of which etiology is based on interaction between genetic susceptibility and environment. However, few studies attempted to identify the risk factors. OBJECTIVE: To investigate the genetic influence and its interaction with environmental quality and stress, as possible risk factors for fibromyalgia development. PATIENTS AND METHODS: This cross-sectional study investigated two groups of women, of which 47 had a clinical diagnosis of fibromyalgia, and 41 women comprising thre control group, all from the town of Novo Hamburgo, RS. The apolipoprotein E (APOE) gene polymorphism was analyzed in DNA extracted from total blood, in both samples. Environmental factors were studied through Lipp's Inventory of Stress Symptoms for Adults and by applying the WHOQOL-100 domain V. RESULTS: Among the patients, more women had high stress levels when compared to the control sample (P < 0.001); moreover, the average scores of the WHOQOL-100 domain V, which analyze environment quality, were lower in this group (P < 0.001). APOE genotypic and allelic frequencies were similar between the two groups. Multivariate analysis showed that low WHOQOL-100 scores increase the chance of disease development by 57.7 times (P < 0.001), and that high stress levels were related with the disease (OR = 197.2; P < 0.001). This approach pointed out an interaction between stress and presence of E*2 allele (P = 0.028). Fibromyalgia was much more frequent in patients with high stress levels that were E*2 non-carriers (estimated OR = 265.1), when compared to patients with the same stress level, but E*2 carriers (estimated OR = 1.06). CONCLUSION: E*2 allele presence could have a protective action regarding the association between fibromyalgia and stress.

Association between environmental quality, stress and APOE gene variation in fibromyalgia susceptibility determination.

INTRODUCTION: Fibromyalgia is a multifactorial disease, of which etiology is based on interaction between genetic susceptibility and environment. However, few studies attempted to identify the risk factors. OBJECTIVE: To investigate the genetic influence and its interaction with environmental quality and stress, as possible risk factors for fibromyalgia development. PATIENTS AND METHODS: This cross-sectional study investigated two groups of women, of which 47 had a clinical diagnosis of fibromyalgia, and 41 women comprising thre control group, all from the town of Novo Hamburgo, RS. The apolipoprotein E (APOE) gene polymorphism was analyzed in DNA extracted from total blood, in both samples. Environmental factors were studied through Lipp's Inventory of Stress Symptoms for Adults and by applying the WHOQOL-100 domain V. RESULTS: Among the patients, more women had high stress levels when compared to the control sample (P < 0.001); moreover, the average scores of the WHOQOL-100 domain V, which analyze environment quality, were lower in this group (P < 0.001). APOE genotypic and allelic frequencies were similar between the two groups. Multivariate analysis showed that low WHOQOL-100 scores increase the chance of disease development by 57.7 times (P < 0.001), and that high stress levels were related with the disease (OR = 197.2; P < 0.001). This approach pointed out an interaction between stress and presence of E*2 allele (P = 0.028). Fibromyalgia was much more frequent in patients with high stress levels that were E*2 non-carriers (estimated OR = 265.1), when compared to patients with the same stress level, but E*2 carriers (estimated OR = 1.06). CONCLUSION: E*2 allele presence could have a protective action regarding the association between fibromyalgia and stress.