Browsing by Author "Akiyama, K."

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Association of genetic variants with non-alcoholic fatty liver disease in an urban Sri Lankan community
(Wiley-Blackwell, 2015) Kasturiratne, A.; Akiyama, K.; Niriella, M.A.; Takeuchi, F.; Isono, M.; Dassanayake, A.S.; de Silva, A.P.; Wickremasinghe, A.R.; Kato, N.; de Silva, H.J.
Genetic variants of NAFLD in an urban Sri Lankan community
(Wiley Blackwell Scientific Publications, 2013) Niriella, M.A.; Kasturiratne, A.; Akiyama, K.; Takeuchi, F.; Isono, M.; Dassanayake, A.S.; de Silva, A.P.; Wickremasinghe, A.R.; Kato, N.; de Silva, H.J.
OBJECTIVE: Recently, genome-wide association studies (GWAS) have successfully identified loci associated with susceptibility to non-alcoholic fatty liver disease (NAFLD) in populations of European descent. No large-scale genetic studies have been performed thus far in South Asian populations. Therefore, as part of a community-based cohort study in an urban adult population of Sri Lankans, we investigated associations of genetic variants with NAFLD, diagnosed on established ultrasound criteria, and its related phenotypes. METHODS: We selected 10 single nucleotide polymorphisms (SNPs), all previously reported to be associated with NAFLD in populations of European and/or South Asian ancestry, for a case-control replication study. They included loci derived from GWAS [PNPLA3 (rs738409), LYPLAL1 (rs12137855), GCKR (rs780094), PPP1R3B (rs4240624) and NCAN (rs2228603)] plus those from candidate gene studies [APOC3 (rs2854117 and rs2854116), ADIPOR2 (rs767870) and STAT3 (rs6503695 and rs9891119)]. Genotype data of 2988 participants were used for the analysis. RESULTS: A significant NAFLD association was observed for PNPLA3 (rs738409) [OR = 1.25, 95% CI 1.08–1.44, P = 0.003)]; rs738409 was also associated with a trend towards lower serum triglycerides APOC3 variants were significantly (P = 7.3–7.5 × 10–8) associated with higher triglycerides, but not with NAFLD (OR = 0.86). Apart from SNP–lipid associations previously reported at the GCKR, PPP1R3B and NCAN loci, there were no other prominent associations. CONCLUSION: Our data confirm that the PNPLA3 gene variant is significantly associated with NAFLD in the general Sri Lankan population but could not replicate previously reported disease associations at other loci, reinforcing the importance of further large-scale study on genetic variants in diverse populations to better understand the pathophysiology of NAFLD.
Systematic fine-mapping of association with BMI and type 2 diabetes at the FTO locus by integrating results from multiple ethnic groups
(Public Library of Science, 2014) Akiyama, K.; Takeuchi, F.; Isono, M.; Chackrewarthy, S.; Nguyen, Q.N.; Wen, W.; Yamamoto, K.; Katsuya, T.; Kasturiratne, A.; Pham, S.T.; Zheng, W.; Matsushita, Y.; Kishimoto, M.; Do, L.D.; Shu, X.O.; Wickremasinghe, A.R.; Kajio, H.; Kato, N.
BACKGROUND/OBJECTIVE: The 16q12.2 locus in the first intron of FTO has been robustly associated with body mass index (BMI) and type 2 diabetes in genome-wide association studies (GWAS). To improve the resolution of fine-scale mapping at FTO, we performed a systematic approach consisting of two parts. METHODS: The first part is to partition the associated variants into linkage disequilibrium (LD) clusters, followed by conditional and haplotype analyses. The second part is to filter the list of potential causal variants through trans-ethnic comparison. RESULTS: We first examined the LD relationship between FTO SNPs showing significant association with type 2 diabetes in Japanese GWAS and between those previously reported in European GWAS. We could partition all the assayed or imputed SNPs showing significant association in the target FTO region into 7 LD clusters. Assaying 9 selected SNPs in 4 Asian-descent populations--Japanese, Vietnamese, Sri Lankan and Chinese (n≤26,109 for BMI association and n≤24,079 for type 2 diabetes association), we identified a responsible haplotype tagged by a cluster of SNPs and successfully narrowed the list of potential causal variants to 25 SNPs, which are the smallest in number among the studies conducted to date for FTO. CONCLUSIONS: Our data support that the power to resolve the causal variants from those in strong LD increases consistently when three distant populations--Europeans, Asians and Africans--are included in the follow-up study. It has to be noted that this fine-mapping approach has the advantage of applicability to the existing GWAS data set in combination with direct genotyping of selected variants.
Trans-ancestry genome-wide association study identifies 12 genetic loci influencing blood pressure and implicates a role for DNA methylation
(Nature Publishing Company, 2015) Kato, N.; Loh, M.; Takeuchi, F.; Verweij, N.; Wang, X.; Zhang, W.; Kelly, T.N.; Saleheen, D.; Lehne, B.; Leach, I.M.; Drong, A.W.; Abbott, J.; Wahl, S.; Tan, S.T.; Scott, W.R.; Campanella, G.; Chadeau-Hyam, M.; Afzal, U.; Ahluwalia, T.S.; Bonder, M.J.; Chen, P.; Dehghan, A.; Edwards, T.L.; Esko, T.; Go, M.J.; Harris, S.E.; Hartiala, J.; Kasela, S.; Kasturiratne, A.; Khor, C.C.; Kleber, M.E.; Li, H.; Mok, Z.Y.; Nakatochi, M.; Sapari, N.S.; Saxena, R.; Stewart, A.F.; Stolk, L.; Tabara, Y.; Teh, A.L.; Wu, Y.; Wu, J.Y.; Zhang, Y.; Aits, I.; Da Silva Couto Alves, A.; Das, S.; Dorajoo, R.; Hopewell, J.C.; Kim, Y.K.; Koivula, R.W.; Luan, J.; Lyytikäinen, L.P.; Nguyen, Q.N.; Pereira, M.A.; Postmus, I.; Raitakari, O.T.; Bryan, M.S.; Scott, R.A.; Sorice, R.; Tragante, V.; Traglia, M.; White, J.; Yamamoto, K.; Zhang, Y.; Adair, L.S.; Ahmed, A.; Akiyama, K.; Asif, R.; Aung, T.; Barroso, I.; Bjonnes, A.; Braun, T.R.; Cai, H.; Chang, L.C.; Chen, C.H.; Cheng, C.Y.; Chong, Y.S.; Collins, R.; Courtney, R.; Davies, G.; Delgado, G.; Do, L.D.; Doevendans, P.A.; Gansevoort, R.T.; Gao, Y.T.; Grammer, T.B.; Grarup, N.; Grewal, J.; Gu, D.; Wander, G.S.; Hartikainen, A.L.; Hazen, S.L.; He, J.; Heng, C.K.; Hixson, J.E.; Hofman, A.; Hsu, C.; Huang, W.; Husemoen, L.L.; Hwang, J.Y.; Ichihara, S.; Igase, M.; Isono, M.; Justesen, J.M.; Katsuya, T.; Kibriya, M.G.; Kim, Y.J.; Kishimoto, M.; Koh, W.P.; Kohara, K.; Kumari, M.; Kwek, K.; Lee, N.R.; Lee, J.; Liao, J.; Lieb, W.; Liewald, D.C.; Matsubara, T.; Matsushita, Y.; Meitinger, T.; Mihailov, E.; Milani, L.; Mills, R.; Mononen, N.; Müller-Nurasyid, M.; Nabika, T.; Nakashima, E.; Ng, H.K.; Nikus, K.; Nutile, T.; Ohkubo, T.; Ohnaka, K.; Parish, S.; Paternoster, L.; Peng, H.; Peters, A.; Pham, S.T.; Pinidiyapathirage, M.J.; Rahman, M.; Rakugi, H.; Rolandsson, O.; Rozario, M.A.; Ruggiero, D.; Sala, C.F.; Sarju, R.; Shimokawa, K.; Snieder, H.; Sparso, T.; Spiering, W.; Starr, J.M.; Stott, D.J.; Stram, D.O.; Sugiyama, T.; Szymczak, S.; Tang, W.H.; Tong, L.; Trompet, S.; Turjanmaa, V.; Ueshima, H.; Uitterlinden, A.G.; Umemura, S.; Vaarasmaki, M.; van Dam, R.M.; van Gilst, W.H.; van Veldhuisen, D.J.; Viikari, J.S.; Waldenberger, M.; Wang, Y.; Wang, A.; Wilson, R.; Wong, T.Y.; Xiang, Y.B.; Yamaguchi, S.; Ye, X.; Young, R.D.; Young, T.L.; Yuan, J.M.; Zhou, X.; Asselbergs, F.W.; Ciullo, M.; Clarke, R.; Deloukas, P.; Franke, A.; Franks, P.W.; Franks, S.; Friedlander, Y.; Gross, M.D.; Guo, Z.; Hansen, T.; Jarvelin, M.R.; Jorgensen, T.; Jukema, J.W.; Kähönen, M.; Kajio, H.; Kivimaki, M.; Lee, J.Y.; Lehtimäki, T.; Linneberg, A.; Miki, T.; Pedersen, O.; Samani, N.J.; Sorensen, T.I.; Takayanagi, R.; Toniolo, D.; BIOS-consortium; CARDIo GRAMplusCD; LifeLines Cohort Study; InterAct Consortium; Ahsan, H.; Allayee, H.; Chen, Y.T.; Danesh, J.; Deary, I.J.; Franco, O.H.; Franke, L.; Heijman, B.T.; Holbrook, J.D.; Isaacs, A.; Kim, B.J.; Lin, X.; Liu, J.; März, W.; Metspalu, A.; Mohlke, K.L.; Sanghera, D.K.; Shu, X.O.; van Meurs, J.B.; Vithana, E.; Wickremasinghe, A.R.; Wijmenga, C.; Wolffenbuttel, B.H.; Yokota, M.; Zheng, W.; Zhu, D.; Vineis, P.; Kyrtopoulos, S.A.; Kleinjans, J.C.; McCarthy, M.I.; Soong, R.; Gieger, C.; Scott, J.; Teo, Y.Y.; He, J.; Elliott, P.; Tai, E.S.; van der Harst, P.; Kooner, J.S.; Chambers, J.C.
We carried out a trans-ancestry genome-wide association and replication study of blood pressurephenotypes among up to 320,251 individuals of East Asian, European and South Asian ancestry. We find genetic variants at 12 new loci to be associated with blood pressure (P = 3.9 × 10(-11) to 5.0 × 10(-21)). The sentinel blood pressure SNPs are enriched for association with DNAmethylation at multiple nearby CpG sites, suggesting that, at some of the loci identified, DNAmethylation may lie on the regulatory pathway linking sequence variation to blood pressure. The sentinel SNPs at the 12 new loci point to genes involved in vascular smooth muscle (IGFBP3, KCNK3, PDE3A and PRDM6) and renal (ARHGAP24, OSR1, SLC22A7 and TBX2) function. The new and known genetic variants predict increased left ventricular mass, circulating levels of NT-proBNP, and cardiovascular and all-cause mortality (P = 0.04 to 8.6 × 10(-6)). Our results provide new evidence for the role of DNA methylation in blood pressure regulation.