@article {1182, title = {Genome-wide association study identifies GPC5 as a novel genetic locus protective against sudden cardiac arrest.}, journal = {PLoS One}, volume = {5}, year = {2010}, month = {2010 Mar 25}, pages = {e9879}, abstract = {

BACKGROUND: Existing studies indicate a significant genetic component for sudden cardiac arrest (SCA) and genome-wide association studies (GWAS) provide an unbiased approach for identification of novel genes. We performed a GWAS to identify genetic determinants of SCA.

METHODOLOGY/PRINCIPAL FINDINGS: We used a case-control design within the ongoing Oregon Sudden Unexpected Death Study (Oregon-SUDS). Cases (n = 424) were SCAs with coronary artery disease (CAD) among residents of Portland, OR (2002-07, population approximately 1,000,000) and controls (n = 226) were residents with CAD, but no history of SCA. All subjects were of White-European ancestry and GWAS was performed using Affymetrix 500K/5.0 and 6.0 arrays. High signal markers were genotyped in SCA cases (n = 521) identified from the Atherosclerosis Risk in Communities Study (ARIC) and the Cardiovascular Health Study (CHS) (combined n = 19,611). No SNPs reached genome-wide significance (p<5x10(-8)). SNPs at 6 loci were prioritized for follow-up primarily based on significance of p<10(-4) and proximity to a known gene (CSMD2, GPR37L1, LIN9, B4GALNT3, GPC5, and ZNF592). The minor allele of GPC5 (GLYPICAN 5, rs3864180) was associated with a lower risk of SCA in Oregon-SUDS, an effect that was also observed in ARIC/CHS whites (p<0.05) and blacks (p<0.04). In a combined Cox proportional hazards model analysis that adjusted for race, the minor allele exhibited a hazard ratio of 0.85 (95\% CI 0.74 to 0.98; p<0.01).

CONCLUSIONS/SIGNIFICANCE: A novel genetic locus for SCA, GPC5, was identified from Oregon-SUDS and successfully validated in the ARIC and CHS cohorts. Three other members of the Glypican family have been previously implicated in human disease, including cardiac conditions. The mechanism of this specific association requires further study.

}, keywords = {Aged, Alleles, Case-Control Studies, Cohort Studies, Death, Sudden, Cardiac, Ethnic Groups, Female, Genetic Predisposition to Disease, Genome-Wide Association Study, Glypicans, Heart Diseases, Humans, Male, Middle Aged, Models, Genetic, Oligonucleotide Array Sequence Analysis, Oregon, Polymorphism, Single Nucleotide}, issn = {1932-6203}, doi = {10.1371/journal.pone.0009879}, author = {Arking, Dan E and Reinier, Kyndaron and Post, Wendy and Jui, Jonathan and Hilton, Gina and O{\textquoteright}Connor, Ashley and Prineas, Ronald J and Boerwinkle, Eric and Psaty, Bruce M and Tomaselli, Gordon F and Rea, Thomas and Sotoodehnia, Nona and Siscovick, David S and Burke, Gregory L and Marb{\'a}n, Eduardo and Spooner, Peter M and Chakravarti, Aravinda and Chugh, Sumeet S} } @article {1205, title = {Polymorphisms in the mitochondrial DNA control region and frailty in older adults.}, journal = {PLoS One}, volume = {5}, year = {2010}, month = {2010 Jun 10}, pages = {e11069}, abstract = {

BACKGROUND: Mitochondria contribute to the dynamics of cellular metabolism, the production of reactive oxygen species, and apoptotic pathways. Consequently, mitochondrial function has been hypothesized to influence functional decline and vulnerability to disease in later life. Mitochondrial genetic variation may contribute to altered susceptibility to the frailty syndrome in older adults.

METHODOLOGY/PRINCIPAL FINDINGS: To assess potential mitochondrial genetic contributions to the likelihood of frailty, mitochondrial DNA (mtDNA) variation was compared in frail and non-frail older adults. Associations of selected SNPs with a muscle strength phenotype were also explored. Participants were selected from the Cardiovascular Health Study (CHS), a population-based observational study (1989-1990, 1992-1993). At baseline, frailty was identified as the presence of three or more of five indicators (weakness, slowness, shrinking, low physical activity, and exhaustion). mtDNA variation was assessed in a pilot study, including 315 individuals selected as extremes of the frailty phenotype, using an oligonucleotide sequencing microarray based on the Revised Cambridge Reference Sequence. Three mtDNA SNPs were statistically significantly associated with frailty across all pilot participants or in sex-stratified comparisons: mt146, mt204, and mt228. In addition to pilot participants, 4,459 additional men and women with frailty classifications, and an overlapping subset of 4,453 individuals with grip strength measurements, were included in the study population genotyped at mt204 and mt228. In the study population, the mt204 C allele was associated with greater likelihood of frailty (adjusted odds ratio = 2.04, 95\% CI = 1.07-3.60, p = 0.020) and lower grip strength (adjusted coefficient = -2.04, 95\% CI = -3.33- -0.74, p = 0.002).

CONCLUSIONS: This study supports a role for mitochondrial genetic variation in the frailty syndrome and later life muscle strength, demonstrating the importance of the mitochondrial genome in complex geriatric phenotypes.

}, keywords = {Aged, Aged, 80 and over, DNA, Mitochondrial, Female, Frail Elderly, Genotype, Humans, Male, Polymorphism, Genetic}, issn = {1932-6203}, doi = {10.1371/journal.pone.0011069}, author = {Moore, Ann Z and Biggs, Mary L and Matteini, Amy and O{\textquoteright}Connor, Ashley and McGuire, Sarah and Beamer, Brock A and Fallin, M Danielle and Fried, Linda P and Walston, Jeremy and Chakravarti, Aravinda and Arking, Dan E} }