Introdução: Mucopolissacaridose IVA é uma doença lisossômica, autossômica recessiva, causada pela deficiência da enzima N-acetilgalactosamina-6-sulfatase. É uma doença rara e a incidência varia de 1:76.000 a 1:640.000 recém-nascidos vivos. Até o momento 319 diferentes mutações causadoras da doença já foram identificadas, o que demonstra a ampla variabilidade genética. Objetivo: Caracterizar o genótipo de pacientes com MPS IVA, analisar 6 polimorfismos intragênicos e identificar os haplótipos presentes em nossos pacientes, através do estudo molecular do gene GALNS. Métodos: O estudo foi realizado em 45 pacientes provenientes das regiões Nordeste, Sudeste, e Sul do Brasil, com diagnóstico bioquímico confirmado para MPS IVA. A análise molecular foi realizada através de PCR seguida de sequenciamento, pelo método de Sanger, a fim de identificar as mutações causadoras da doença. Para o estudo de haplótipos foram analisados 6 polimorfismos intragênicos através de PCR em Tempo Real, pelo método Taqman, em pacientes e controles. Resultados: A análise do gene GALNS, nos 45 pacientes, permitiu a identificação de 18 diferentes mutações, e a caracterização de 6 haplótipos distintos. Das 18 mutações encontradas, 5 apresentaram uma alta frequência (p.Ser341Arg, p.Arg386Cys, p.Gly301Cys, p.Arg94Leu e p.Gly116Ser), além disso, foram encontradas 4 novas mutações em outros três pacientes (p.Gly115Arg, p.Asn45Gly, p.Thr394Ala e c.759-2A>G). Dentre as mutações encontradas com maior frequência, a mutação p.Ser341Arg foi identificada em um maior número de pacientes, sendo a maioria proveniente da região Nordeste. Além disso, todos os pacientes com esta mutação apresentaram um único haplótipo. Conclusão: Os resultados obtidos permitiram a identificação de 18 mutações dentre elas 4 novas mutações. A alta frequência da mutação p.Ser341Arg no Nordeste do Brasil, principalmente no estado da Paraíba nos leva a inferir um possível efeito fundador da doença. Esta mutação foi observada somente na população brasileira e todos os pacientes com mutação em homozigose apresentaramum único haplótipo. Estas análises são importantes para identificar portadores nas famílias, para diagnóstico pré-natal, e também como forma de identificar uma origem comum em mutações frequentes em determinadas populações. / Background: Mucopolysaccharidosis IVA is an autosomal recessive lysosomal disease, caused by deficiency of N-acetilgalactosamina-6-sulfatase. It is a rare disease and the incidence ranges from 1: 76,000 to 1:640,000 live births. To date 319 mutations have been identified in this gene, demonstrating the wide variability of disease causing mutations. Objective: Analyze and characterize the genotype of patients with MPS IVA, through molecular analysis of GALNS. Methods: Molecular analysis of 45 patients with confirmed biochemical diagnosis for MPS IVA was performed. Mutation analysis was performed by PCR followed by Sanger sequencing. Haplotype analysis was performed using 6 intragenic polymorphisms by Real-Time PCR. Results: In this study we found 18 different mutations among 45 Brazilian patients and identified 5 common mutations (p.Ser341Arg, p.Arg386Cys, p.Gly301Cys, p.Arg94Leu e p.Gly116Ser). Four novel mutations were also identified through molecular analysis, including: p.Gly115Arg, p.Asn45Gly, p.Thr394Ala e c.759-2A>G. Patients are distributed in Northeast, Southeast and South regions of Brazil. Six different haplotypes were identified among patients. The p.Ser341Arg mutation showed the highest frequency, and most patients are located in the Northeast, additionally, all patients with this mutation show the same haplotype.Conclusion: These analyzes are important to identify carriers in families, for prenatal diagnosis, and in order to identify the mutation origin when certain recurrent mutation is associated with the same haplotype. In this study, we observed a high frequency of p.Ser341Arg mutation in Northeast, mainly in the state of Paraíba. This mutation was detected with higher frequency among patients, and showed only a haplotype. This mutation is unique for the Brazilian population and thus, we could suggest that a possible founder effect for this mutation could exist.

Orientador: José Eduardo Tanus dos Santos / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-17T23:52:34Z (GMT). No. of bitstreams: 1 Belo_VanessadeAlmeida_M.pdf: 3576019 bytes, checksum: c9ba06079f310fba660d5bfb890b000a (MD5) Previous issue date: 2011 / Resumo: A obesidade em crianças e adolescentes constitui-se num importante fator de risco para doenças cardiovasculares, em especial, aterosclerose. Esta condição é caracterizada por acúmulo de lipídeos e elementos fibrosos em artérias de grande calibre em que mecanismos inflamatórios e remodelamento vascular estão envolvidos. Neste contexto, a metaloproteinase-9 de matriz extracelular (MMP-9) - endopeptidase capaz de degradar componentes da matriz extracelular - e seu inibidor endógeno preferencial, inibidor tecidual de MMP (TIMP-1) são importantes mediadores deste remodelamento e um equilíbrio entre MMP-9 e TIMP-1 deve existir a fim de manter a integridade do sistema cardiovascular. Ademais, níveis aumentados de MMP-9 são observados em pacientes com doenças cardiovasculares e estudos genéticos têm mostrado ainda que polimorfismos funcionais no gene da MMP-9 têm sido relacionados à presença e severidade de doenças cardiovasculares. Contudo, ainda não se sabe como a associação desses polimorfismos com a obesidade infantil pode afetar as concentrações de MMP-9 no plasma. Logo, os objetivos desse trabalho foram: 1) comparar as concentrações plasmáticas de MMP-9, TIMP-1 e razão MMP-9/TIMP-1 (atividade líquida da MMP-9) entre crianças e adolescentes obesos e controles; 2) comparar as frequências genotípicas e haplotípicas dos polimorfismos C-1562T, -90(CA)14-24 e Q279R da MMP-9 entre obesos e controles e 3) correlacionar as concentrações de MMP-9 aos genótipos e haplótipos da MMP-9. Inicialmente, determinaram-se os níveis de pro-MMP-9 e no plasma, por zimografia, e as concentrações plasmáticas de MMP-9 e TIMP-1 em obesos e controles por ELISA. Nós não encontramos diferenças nas concentrações plasmáticas de MMP-9 e razão MMP-9/TIMP-1 entre obesos e controles. No entanto, nossos resultados revelaram que em obesos houve diminuição de TIMP-1. Em seguida, extraiu-se o DNA dos voluntários e determinaram-se as frequências genotípicas dos polimorfismos C -1562T e (CA)n, por PCR seguida de eletroforese, do polimorfismo Q279R, por PCR em tempo real, e as frequências haplotípicas, pelo programas PHASE. Não houve diferenças nas frequências genotípicas e haplotípicas entre os grupos. Nós avaliamos a relevância de diferentes genótipos e haplótipos nas concentrações plasmáticas de MMP-9. Para os polimorfismos C-1562T e Q279R, nós encontramos que no grupo de obesos, portadores dos genótipos CC apresentaram menores níveis de MMP-9 quando comparados aos portadores dos genótipos CT+TT e aos controles com mesmo genótipo. No grupo de obesos, portadores do genótipo QQ apresentaram menores níveis de MMP-9 quando comparados aos portadores do genótipo RR e aos controles com mesmo genótipo. Para o polimorfismo -90(CA) 14-24 não observamos diferenças nos níveis de MMP-9 entre os grupos genotípicos. Em relação aos haplótipos, no grupo de obesos, portadores do haplótipo H2 apresentaram menores concentrações de MMP-9 e da razão MMP-9/TIMP-1 (atividade líquida de MMP-9) quando comparados aos outros haplótipos e aos controles com mesmo haplótipo. No grupo controle, não observamos influência dos genótipos e haplótipos nas concentrações plasmáticas de MMP-9. Portanto, nossos achados que sugerem que genótipos (CC e QQ) e o haplótipo H2 podem diminuir os níveis circulantes de MMP-9 em crianças e adolescentes obesos, mas não em crianças saudáveis, consequentemente, estes genótipos e haplótipo poderiam oferecer proteção contra doenças cardiovasculares somente em crianças obesas / Abstract: The childhood obesity is important risk factor for cardiovascular diseases, in particular, atherosclerose. This condition is characterized by the accumulation of lipids and fibrous elements in the large arteries in which inflammatory mechanisms and vascular remodeling are involved. In this context, matrix metalloproteinase 9 (MMP-9) - endopeptidade capable of degrading components of extracellular matrix - and its endogenous inhibitor preferential, the tissue inhibitors of MMP (TIMP-1) are important mediators of this remodeling and a critical equilibrium between MMP-9 and TIMP-1 must exist in order to maintain the integrity of cardiovascular system. Moreover, elevated levels of MMP-9 have been reported in patients with cardiovascular diseases, and genetic studies showing that functional polymorphism MMP-9 gene were related to presence and severity of cardiovascular diseases. However, it remains unclear how the association of these polymorphisms with childhood obesity can affect MMP-9 plasma concentrations. Thus, the objectives of this study were: 1) to compare plasma MMP-9, TIMP-1 and MMP-9/TIMP-1(activity) ratio between obese and control groups; 2) to compare the genotype and haplotype frequencies of MMP-9 polymorphisms (C-1562T and (CA)14-24 and Q279R) between obese and control and, 3) correlate the MMP-9 concentrations with MMP-9 genotypes and haplotypes. To achieve our first goal, we determined the plasma pro-MMP-9 levels by zymography, and plasma MMP-9 and TIMP-1 concentrations by ELISA in obese and control. We not found differences in MMP-9 plasma concentratios and MMP-9/TIMP-1 between obese and control. However, our results showed that obese had lower plasma TIMP-1 concentrations than control. Moreover, to achieve our second goal, we firstly extracted DNA from volunteers, and then we determined the genotype frequencies of C-1562T and (CA)14-24 polymorphisms by PCR followed by electrophoresis, of and Q279R polymorphism by real time PCR, and the haplotype frequencies by the programs PHASE. We found similar genotype and allelic distribution for the three polymorphisms when study groups were compared. We evaluated the relevance of different genotypes in plasma MMP-9 concentrations in study groups. To the C-1562T and Q279R polymorphisms, we found that in the obese group, CC genotype carries had lower MMP-9 levels when compared with CT+TT genotype carries and control with the same genotype. In the obese group, QQ genotype carries had lower MMP-9 levels when compared with RR genotype carries and control the same genotype. To the -90(CA)14-24 polymorphism, we did not observe differences in the MMP-9 levels among different genotypic groups. In relation to haplotypes, we found that in the obese group, H2 haplotype carriers had lower MMP-9 levels and MMP-9/TIMP-1 ratio when compared other haplotypes and control with the same haplotype. Therefore, our findings suggest that (CC and QQ) genotypes and H2 haplotype decrease circulating MMP-9 levels in obese but not in healthy children, thus genotypes and haplotype could offer protection against cardiovascular diseases in those children / Mestrado / Farmacologia / Doutor em Farmacologia

Orientador: Jose Eduardo Tanus dos Santos / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas / Made available in DSpace on 2018-08-14T10:45:46Z (GMT). No. of bitstreams: 1 Dias_VaniaBraghinideRezende.pdf: 2420134 bytes, checksum: db28114d3602e3e14b5763e165a73cfc (MD5) Previous issue date: 2009 / Resumo: Mulheres grávidas constituem um grupo de indivíduos particularmente mais susceptíveis aos efeitos tóxicos associados ao chumbo (Pb)[1]. O chumbo é um metal pesado que se acumula nos tecidos mineralizados. Possui um comportamento similar ao cálcio, o que explica sua toxicidade. Durante a gravidez, o remodelamento ósseo promove a migração do chumbo para o plasma e como resultado, o metal é transferido para o feto, mesmo se a mãe foi exposta há vários anos [2]. Durante a exposição materna, cerca de 99% do chumbo absorvido, aqui referenciado como Pb-Sangue Total, permanece associado a enzima acido d-aminolevulinico desidratase (ALAD) no eritrócito. O restante (cerca de 1%), aqui referenciado como Pb-Plasma (e/ou Soro), permanece livre e eventualmente se deposita nos tecidos mineralizados (ossos e dentes)[2]. O Pb-Sangue Total e Pb-Plasma (ou Soro) são naturalmente correlacionados, mas essa correlação ainda não está bem compreendida, sendo essencial a medida dos dois parâmetros para esclarecer esses processos. Além disso, os fatores genéticos são de crucial importância, com alguns genes como o da ALAD e o do receptor da vitamina D (VDR) tendo sido associados a diferentes concentrações sanguíneas e plasmáticas de chumbo em indivíduos expostos[3]. A dinâmica do chumbo durante a gravidez também tem um papel importante nesse processo e deve ser considerada. Até o momento, nenhum trabalho havia estudado os fatores genéticos acima citados, numa população especialmente exposta e susceptível aos efeitos deletérios do chumbo. Mesmo quando a exposição materna cessa, o chumbo permanece alojado nos ossos por vários anos e será mobilizado através do remodelamento ósseo, contaminando o feto. Haveria um grupo de gestantes, segundo genótipos, predisposto a maiores ou menores aumentos do metal no plasma e fração plasmática? Teriam maior re-exposição ao chumbo durante períodos de acentuado remodelamento ósseo? Para responder a essas questões, esse estudo concentrou nas medidas do metal no Sangue e Plasma e/ou Soro (sendo o Soro equivalente ao plasma) e na avaliação da susceptibilidade genética das grávidas através do estudo dos polimorfismos dos genes ALAD e VDR, além da análise de polimorfismos agrupados em haplótipos. Nós não encontramos diferenças significativas para o grupo de genótipos da ALAD, nem mesmo para os genótipos do VDR. Porém, as principais descobertas foram que o grupo de haplótipos H8 do VDR (f, a, b) estão associados às mais baixas concentrações de Pb no Soro e na razão Pb-Soro/Pb-Sangue Total. Esses resultados sugerem que esse grupo de gestantes, mesmo expostas às mesmas concentrações de Pb, acumula e/ou reabsorvem menos Pb que os grupos com outros haplótipos. Além disso, é importante ressaltar que analisando apenas a concentração de Pb no sangue total, não seria possível chegar a essa conclusão. / Abstract: Pregnant women constitute a group of subjects particularly susceptible to toxic effects due to exposure to lead (Pb). Lead is a heavy metal which accumulates in bone tissues and has a behavior that is similar to calcium, thus explaining its toxicity. In particular, the increase in bone resorption processes that take place during pregnancy cause lead migration into the maternal plasma. As a result, lead transference to the fetus may take place even years after the mother's last exposure. During maternal exposure, most (99%) of the absorbed lead (here referred to as Pb-Blood) remains associated to d - aminolevulinic acid dehydratase within erytrocytes. The remaining (2% to 10%, here referred to as Pb-Plasma) lead remains free and is eventually deposited - and accumulated - in the bone tissues (teeth and bones). The Pb-Blood and Pb-Plasma are naturally correlated, but the correlation is not well understood, making it essential to measure both quantities in studies aimed at clarifying these processes. Also of crucial importance are genetic factors, with some genes such as ALAD and VDR been associated with Pb-Blood and Pb-Plasma concentrations. The dynamics of lead migration during pregnancy also plays a major role in the process and therefore must also be considered. Even after the mother's exposure has ceased, lead remains accumulated in the teeth and bones for many years and is mobilized by processes of bone resorption such as those taking place during pregnancy. Is there a group of pregnant women, according to genotypes, that is more prone to higher or lower Pb concentations in plasma? Is that group more exposed to Pb due to greater Pb absorption or reabsorption through bone remodeling? To address these questions, this study focused on the measurement of Pb-Blood and Pb-Serum (the same of plasma) and on genetic susceptibility of pregnant women. We found no significant differences among different ALAD or VDR genotype groups. However, the main findings reported here are that haplotype H8 of VDR (f, a, b) is associated with lower Pb-Serum concentration and lower Pb-Serum/Pb-Blood ratios. Therefore, pregnant women with this haplotype have lower Pb-serum, even when exposed to the same Pb-Blood concentrations. Interestingly, we would not have make this conclusion by assessing only Pb-Blood concentrations. / Universidade Estadual de Campi / Farmacologia / Doutor em Farmacologia

This mini-review investigates and compiles the latest knowledge regarding epigenetic changes on the mammalian mitochondrial DNA and its proteins. Methylation of the DNA, acetylation of the proteins and silencing of genes by short non-coding RNAs are the main epigenetic changes known today to affect mitochondrial DNA, mostly leading to repression. Methylation mainly occurs at non-CpG sites in the main non-coding region called the D-loop, with methylation patterns being cell type specific. Acetylation of proteins are mainly controlled by the deacetylase SIRT3, with its function being correlated to longevity. On the other hand, mitochondrial dysfunction is directly associated with a plethora of diseases, such as neurodegenerative disorders and heart disorders. The mitochondrion and nucleus are immensely dependent on each other and exchange vital proteins and RNAs, with epigenetic changes on one potentially affecting the other. Recent research shows that heteroplasmy is a proven cause of mitochondrial malfunction and that paternal inheritance is possible. The mitochondrial haplotype also shows different vulnerability to certain diets and diseases, leading to the conclusion that the mitochondrial haplotype can be used to more than just tracing human origins, such as to predicting and preventing diseases.

The heparan sulfate 6-O-sulfotransferase 3 (HS6ST3) gene is involved in heparan sulphate and heparin metabolism, and has been reported to be associated with diabetic retinopathy in type 2 diabetes. We hypothesized that HS6ST3 gene polymorphisms might play an important role in obesity and related phenotypes (such as triglycerides). We examined genetic associations of 117 single-nucleotide polymorphisms (SNPs) within the HS6ST3 gene with obesity and triglycerides using two Caucasian samples: the Marshfield sample (1442 obesity cases and 2122 controls), and the Health aging and body composition (Health ABC) sample (305 cases and 1336 controls). Logistic regression analysis of obesity as a binary trait and linear regression analysis of triglycerides as a continuous trait, adjusted for age and sex, were performed using PLINK. Single marker analysis showed that six SNPs in the Marshfield sample and one SNP in the Health ABC sample were associated with obesity (P < 0.05). SNP rs535812 revealed a stronger association with obesity in meta-analysis of these two samples (P = 0.0105). The T-A haplotype from rs878950 and rs9525149 revealed significant association with obesity in the Marshfield sample (P = 0.012). Moreover, nine SNPs showed associations with triglycerides in the Marshfield sample (P < 0.05) and the best signal was rs1927796 (P = 0.00858). In addition, rs7331762 showed a strong gene × gender interaction (P = 0.00956) for obesity while rs1927796 showed a strong gene × gender interaction (P = 0.000625) for triglycerides in the Marshfield sample. These findings contribute new insights into the pathogenesis of obesity and triglycerides and demonstrate the importance of gender differences in the aetiology.

Variants (such as rs9939609) in the fat mass- and obesity-associated (FTO) gene have been associated with obesity, type 2 diabetes, some cancers, and alcohol consumption. This study tested the associations of 167 single-nucleotide polymorphisms (SNPs) within FTO gene with alcohol dependence (AD) using two Caucasian samples: the Collaborative Study on the Genetics of Alcoholism (COGA) sample (660 AD cases and 400 controls) and the Study of Addiction: Genetics and Environment (SAGE) sample (623 cases and 1,016 controls). Logistic regression analysis of AD as a binary trait was performed using the PLINK software. For the SAGE sample, the top three SNPs showing associations with AD were rs8062891, rs1108086, and rs1420318 (p = 0.00088, 0.00086 and 0.00086, respectively). Two SNPs (rs12597786 and rs7204609) associated with AD in the SAGE sample (p = 0.017 and 0.034, respectively) were replicated in the COGA sample (p = 0.017 and 0.014, respectively). Through meta-analysis of two samples using PLINK, the top three SNPs associated with AD were rs8062891, rs12597786, and rs7204609 (p = 0.00064, 0.00076 and 0.0011, respectively). Haplotype analysis in the SAGE sample further supported the associations with AD in single-marker analysis. In addition, we found association of rs17817449 (which has a strong linkage disequilibrium with rs9939609) with AD in the SAGE sample (p = 0.00339). The findings provide evidence of joint intervention and prevention of AD and obesity.

HLA-DRA gene polymorphisms might play an important role in alcohol dependence (AD). We examined genetic associations of 29 single-nucleotide polymorphisms (SNPs) within the HLA-DRA gene with AD using two Caucasian samples - the Collaborative Study on the Genetics of Alcoholism (COGA) sample (660 AD cases and 400 controls) and the Study of Addiction: Genetics and Environment (SAGE) sample (623 cases and 1,016 controls). Logistic regression analysis using PLINK showed that 16 SNPs were associated with AD in the COGA sample and 13 SNPs were associated with AD in the SAGE sample (p < 0.05). The best novel signal was SNP rs2239803 associated with AD in both samples (p = 0.000817 for the COGA sample and p = 0.0026 for the SAGE sample, respectively) while one flanking SNP rs4935356 also showed strong association in both samples (p = 0.00219 and 0.0026 for the COGA and SAGE samples, respectively). Furthermore, these two SNPs revealed stronger associations in meta-analysis of these two samples (p = 8.97 × 10-6 and 2.02 × 10-5 for rs2239803 and rs4935356, respectively). In addition, the G-A haplotype from these two SNPs revealed a significant association with AD in both the COGA and SAGE samples (p = 0.0007 and 0.0019, respectively). These findings highlight the novel associations with HLA-DRA that may play an important role in the etiology of AD.

The heparan sulfate 6-O-sulfotransferase 3 (HS6ST3) gene is involved in heparan sulphate and heparin metabolism, and has been reported to be associated with diabetic retinopathy in type 2 diabetes. We hypothesized that HS6ST3 gene polymorphisms might play an important role in obesity and related phenotypes (such as triglycerides). We examined genetic associations of 117 single-nucleotide polymorphisms (SNPs) within the HS6ST3 gene with obesity and triglycerides using two Caucasian samples: the Marshfield sample (1442 obesity cases and 2122 controls), and the Health aging and body composition (Health ABC) sample (305 cases and 1336 controls). Logistic regression analysis of obesity as a binary trait and linear regression analysis of triglycerides as a continuous trait, adjusted for age and sex, were performed using PLINK. Single marker analysis showed that six SNPs in the Marshfield sample and one SNP in the Health ABC sample were associated with obesity (P < 0.05). SNP rs535812 revealed a stronger association with obesity in meta-analysis of these two samples (P = 0.0105). The T-A haplotype from rs878950 and rs9525149 revealed significant association with obesity in the Marshfield sample (P = 0.012). Moreover, nine SNPs showed associations with triglycerides in the Marshfield sample (P < 0.05) and the best signal was rs1927796 (P = 0.00858). In addition, rs7331762 showed a strong gene × gender interaction (P = 0.00956) for obesity while rs1927796 showed a strong gene × gender interaction (P = 0.000625) for triglycerides in the Marshfield sample. These findings contribute new insights into the pathogenesis of obesity and triglycerides and demonstrate the importance of gender differences in the aetiology.

Variants (such as rs9939609) in the fat mass- and obesity-associated (FTO) gene have been associated with obesity, type 2 diabetes, some cancers, and alcohol consumption. This study tested the associations of 167 single-nucleotide polymorphisms (SNPs) within FTO gene with alcohol dependence (AD) using two Caucasian samples: the Collaborative Study on the Genetics of Alcoholism (COGA) sample (660 AD cases and 400 controls) and the Study of Addiction: Genetics and Environment (SAGE) sample (623 cases and 1,016 controls). Logistic regression analysis of AD as a binary trait was performed using the PLINK software. For the SAGE sample, the top three SNPs showing associations with AD were rs8062891, rs1108086, and rs1420318 (p = 0.00088, 0.00086 and 0.00086, respectively). Two SNPs (rs12597786 and rs7204609) associated with AD in the SAGE sample (p = 0.017 and 0.034, respectively) were replicated in the COGA sample (p = 0.017 and 0.014, respectively). Through meta-analysis of two samples using PLINK, the top three SNPs associated with AD were rs8062891, rs12597786, and rs7204609 (p = 0.00064, 0.00076 and 0.0011, respectively). Haplotype analysis in the SAGE sample further supported the associations with AD in single-marker analysis. In addition, we found association of rs17817449 (which has a strong linkage disequilibrium with rs9939609) with AD in the SAGE sample (p = 0.00339). The findings provide evidence of joint intervention and prevention of AD and obesity.

HLA-DRA gene polymorphisms might play an important role in alcohol dependence (AD). We examined genetic associations of 29 single-nucleotide polymorphisms (SNPs) within the HLA-DRA gene with AD using two Caucasian samples - the Collaborative Study on the Genetics of Alcoholism (COGA) sample (660 AD cases and 400 controls) and the Study of Addiction: Genetics and Environment (SAGE) sample (623 cases and 1,016 controls). Logistic regression analysis using PLINK showed that 16 SNPs were associated with AD in the COGA sample and 13 SNPs were associated with AD in the SAGE sample (p < 0.05). The best novel signal was SNP rs2239803 associated with AD in both samples (p = 0.000817 for the COGA sample and p = 0.0026 for the SAGE sample, respectively) while one flanking SNP rs4935356 also showed strong association in both samples (p = 0.00219 and 0.0026 for the COGA and SAGE samples, respectively). Furthermore, these two SNPs revealed stronger associations in meta-analysis of these two samples (p = 8.97 × 10-6 and 2.02 × 10-5 for rs2239803 and rs4935356, respectively). In addition, the G-A haplotype from these two SNPs revealed a significant association with AD in both the COGA and SAGE samples (p = 0.0007 and 0.0019, respectively). These findings highlight the novel associations with HLA-DRA that may play an important role in the etiology of AD.