Browsing by Author "Zhu, Congcong"

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    APOE Promoter Polymorphism-219T/G is an Effect Modifier of the Influence of APOE ε4 on Alzheimer's Disease Risk in a Multiracial Sample
    (MDPI, 2019-08-16) Choi, Kyu Yeong; Lee, Jang Jae; Gunasekaran, Tamil Iniyan; Kang, Sarang; Lee, Wooje; Jeong, Jangho; Lim, Ho Jae; Zhang, Xiaoling; Zhu, Congcong; Won, So-Yoon; Choi, Yu Yong; Seo, Eun Hyun; Lee, Seok Cheol; Gim, Jungsoo; Chung, Ji Yeon; Chong, Ari; Byun, Min Soo; Seo, Sujin; Ko, Pan-Woo; Han, Ji-Won; McLean, Catriona; Farrell, John; Lunetta, Kathryn L.; Miyashita, Akinori; Hara, Norikazu; Won, Sungho; Choi, Seong-Min; Ha, Jung-Min; Jeong, Jee Hyang; Kuwano, Ryozo; Song, Min Kyung; An, Seong Soo A.; Lee, Young Min; Park, Kyung Won; Lee, Ho-Won; Choi, Seong Hye; Rhee, Sangmyung; Song, Woo Keun; Lee, Jung Sup; Mayeux, Richard; Haines, Jonathan L.; Pericak-Vance, Margaret A.; Choo, IL Han; Nho, Kwangsik; Kim, Ki-Woong; Lee, Dong Young; Kim, SangYun; Kim, Byeong C.; Kim, Hoowon; Jun, Gyungah R.; Schellenberg, Gerard D.; Ikeuchi, Takeshi; Farrer, Lindsay A.; Lee, Kun Ho; Radiology and Imaging Sciences, School of Medicine
    Variants in the APOE gene region may explain ethnic differences in the association of Alzheimer's disease (AD) with ε4. Ethnic differences in allele frequencies for three APOE region SNPs (single nucleotide polymorphisms) were identified and tested for association in 19,398 East Asians (EastA), including Koreans and Japanese, 15,836 European ancestry (EuroA) individuals, and 4985 African Americans, and with brain imaging measures of cortical atrophy in sub-samples of Koreans and EuroAs. Among ε4/ε4 individuals, AD risk increased substantially in a dose-dependent manner with the number of APOE promoter SNP rs405509 T alleles in EastAs (TT: OR (odds ratio) = 27.02, p = 8.80 × 10-94; GT: OR = 15.87, p = 2.62 × 10-9) and EuroAs (TT: OR = 18.13, p = 2.69 × 10-108; GT: OR = 12.63, p = 3.44 × 10-64), and rs405509-T homozygotes had a younger onset and more severe cortical atrophy than those with G-allele. Functional experiments using APOE promoter fragments demonstrated that TT lowered APOE expression in human brain and serum. The modifying effect of rs405509 genotype explained much of the ethnic variability in the AD/ε4 association, and increasing APOE expression might lower AD risk among ε4 homozygotes.
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    Genome-wide association study of phenotypes measuring progression from first cocaine or opioid use to dependence reveals novel risk genes
    (Open Exploration, 2021) Sherva, Richard; Zhu, Congcong; Wetherill, Leah; Edenberg, Howard J.; Johnson, Emma; Degenhardt, Louisa; Agrawal, Arpana; Martin, Nicholas G.; Nelson, Elliot; Kranzler, Henry R.; Gelernter, Joel; Farrer, Lindsay A.; Medical and Molecular Genetics, School of Medicine
    Aim: Substance use disorders (SUD) result in substantial morbidity and mortality worldwide. Opioids, and to a lesser extent cocaine, contribute to a large percentage of this health burden. Despite their high heritability, few genetic risk loci have been identified for either opioid or cocaine dependence (OD or CD, respectively). A genome-wide association study of OD and CD related phenotypes reflecting the time between first self-reported use of these substances and a first DSM-IV dependence diagnosis was conducted. Methods: Cox proportional hazards regression in a discovery sample of 6,188 African-Americans (AAs) and 6,835 European-Americans (EAs) participants in a genetic study of multiple substance dependence phenotypes were used to test for association between genetic variants and these outcomes. The top findings were tested for replication in two independent cohorts. Results: In the discovery sample, three independent regions containing variants associated with time to dependence at P < 5 x 10-8 were identified, one (rs61835088 = 1.03 x 10-8) for cocaine in the combined EA-AA meta-analysis in the gene FAM78B on chromosome 1, and two for opioids in the AA portion of the sample in intergenic regions of chromosomes 4 (rs4860439, P = 1.37 x 10-8) and 9 (rs7032521, P = 3.30 x 10-8). After meta-analysis with data from the replication cohorts, the signal at rs61835088 improved (HR = 0.87, P = 3.71 x 10-9 and an intergenic SNP on chromosome 21 (rs2825295, HR = 1.14, P = 2.57 x 10-8) that missed the significance threshold in the AA discovery sample became genome-wide significant (GWS) for CD. Conclusions: Although the two GWS variants are not in genes with obvious links to SUD biology and have modest effect sizes, they are statistically robust and show evidence for association in independent samples. These results may point to novel pathways contributing to disease progression and highlight the utility of related phenotypes to better understand the genetics of SUDs.