@article {5864, title = {Genetic determinants of the ankle-brachial index: a meta-analysis of a cardiovascular candidate gene 50K SNP panel in the candidate gene association resource (CARe) consortium.}, journal = {Atherosclerosis}, volume = {222}, year = {2012}, month = {2012 May}, pages = {138-47}, abstract = {

BACKGROUND: Candidate gene association studies for peripheral artery disease (PAD), including subclinical disease assessed with the ankle-brachial index (ABI), have been limited by the modest number of genes examined. We conducted a two stage meta-analysis of \~{}50,000 SNPs across \~{}2100 candidate genes to identify genetic variants for ABI.

METHODS AND RESULTS: We studied subjects of European ancestry from 8 studies (n=21,547, 55\% women, mean age 44-73 years) and African American ancestry from 5 studies (n=7267, 60\% women, mean age 41-73 years) involved in the candidate gene association resource (CARe) consortium. In each ethnic group, additive genetic models were used (with each additional copy of the minor allele corresponding to the given beta) to test each SNP for association with continuous ABI (excluding ABI>1.40) and PAD (defined as ABI<0.90) using linear or logistic regression with adjustment for known PAD risk factors and population stratification. We then conducted a fixed-effects inverse-variance weighted meta-analyses considering a p<2{\texttimes}10(-6) to denote statistical significance.

RESULTS: In the European ancestry discovery meta-analyses, rs2171209 in SYTL3 (β=-0.007, p=6.02{\texttimes}10(-7)) and rs290481 in TCF7L2 (β=-0.008, p=7.01{\texttimes}10(-7)) were significantly associated with ABI. None of the SNP associations for PAD were significant, though a SNP in CYP2B6 (p=4.99{\texttimes}10(-5)) was among the strongest associations. These 3 genes are linked to key PAD risk factors (lipoprotein(a), type 2 diabetes, and smoking behavior, respectively). We sought replication in 6 population-based and 3 clinical samples (n=15,440) for rs290481 and rs2171209. However, in the replication stage (rs2171209, p=0.75; rs290481, p=0.19) and in the combined discovery and replication analysis the SNP-ABI associations were no longer significant (rs2171209, p=1.14{\texttimes}10(-3); rs290481, p=8.88{\texttimes}10(-5)). In African Americans, none of the SNP associations for ABI or PAD achieved an experiment-wide level of significance.

CONCLUSIONS: Genetic determinants of ABI and PAD remain elusive. Follow-up of these preliminary findings may uncover important biology given the known gene-risk factor associations. New and more powerful approaches to PAD gene discovery are warranted.

}, keywords = {Adult, African Americans, Aged, Ankle Brachial Index, Aryl Hydrocarbon Hydroxylases, Cytochrome P-450 CYP2B6, European Continental Ancestry Group, Female, Humans, Male, Middle Aged, Oxidoreductases, N-Demethylating, Peripheral Arterial Disease, Polymorphism, Single Nucleotide, Risk Factors, Transcription Factor 7-Like 2 Protein}, issn = {1879-1484}, doi = {10.1016/j.atherosclerosis.2012.01.039}, author = {Wassel, Christina L and Lamina, Claudia and Nambi, Vijay and Coassin, Stefan and Mukamal, Kenneth J and Ganesh, Santhi K and Jacobs, David R and Franceschini, Nora and Papanicolaou, George J and Gibson, Quince and Yanek, Lisa R and van der Harst, Pim and Ferguson, Jane F and Crawford, Dana C and Waite, Lindsay L and Allison, Matthew A and Criqui, Michael H and McDermott, Mary M and Mehra, Reena and Cupples, L Adrienne and Hwang, Shih-Jen and Redline, Susan and Kaplan, Robert C and Heiss, Gerardo and Rotter, Jerome I and Boerwinkle, Eric and Taylor, Herman A and Eraso, Luis H and Haun, Margot and Li, Mingyao and Meisinger, Christa and O{\textquoteright}Connell, Jeffrey R and Shuldiner, Alan R and Tybj{\ae}rg-Hansen, Anne and Frikke-Schmidt, Ruth and Kollerits, Barbara and Rantner, Barbara and Dieplinger, Benjamin and Stadler, Marietta and Mueller, Thomas and Haltmayer, Meinhard and Klein-Weigel, Peter and Summerer, Monika and Wichmann, H-Erich and Asselbergs, Folkert W and Navis, Gerjan and Mateo Leach, Irene and Brown-Gentry, Kristin and Goodloe, Robert and Assimes, Themistocles L and Becker, Diane M and Cooke, John P and Absher, Devin M and Olin, Jeffrey W and Mitchell, Braxton D and Reilly, Muredach P and Mohler, Emile R and North, Kari E and Reiner, Alexander P and Kronenberg, Florian and Murabito, Joanne M} }