@article {1156, title = {Genome-wide association studies of MRI-defined brain infarcts: meta-analysis from the CHARGE Consortium.}, journal = {Stroke}, volume = {41}, year = {2010}, month = {2010 Feb}, pages = {210-7}, abstract = {

BACKGROUND AND PURPOSE: Previous studies examining genetic associations with MRI-defined brain infarct have yielded inconsistent findings. We investigated genetic variation underlying covert MRI infarct in persons without histories of transient ischemic attack or stroke. We performed meta-analysis of genome-wide association studies of white participants in 6 studies comprising the Cohorts for Heart and Aging Research in Genomic Epidemiology (CHARGE) consortium.

METHODS: Using 2.2 million genotyped and imputed single nucleotide polymorphisms, each study performed cross-sectional genome-wide association analysis of MRI infarct using age- and sex-adjusted logistic regression models. Study-specific findings were combined in an inverse-variance-weighted meta-analysis, including 9401 participants with mean age 69.7 (19.4\% of whom had >or=1 MRI infarct).

RESULTS: The most significant association was found with rs2208454 (minor allele frequency, 20\%), located in intron 3 of MACRO domain containing 2 gene and in the downstream region of fibronectin leucine-rich transmembrane protein 3 gene. Each copy of the minor allele was associated with lower risk of MRI infarcts (odds ratio, 0.76; 95\% confidence interval, 0.68-0.84; P=4.64x10(-7)). Highly suggestive associations (P<1.0x10(-5)) were also found for 22 other single nucleotide polymorphisms in linkage disequilibrium (r(2)>0.64) with rs2208454. The association with rs2208454 did not replicate in independent samples of 1822 white and 644 black participants, although 4 single nucleotide polymorphisms within 200 kb from rs2208454 were associated with MRI infarcts in the black population sample.

CONCLUSIONS: This first community-based, genome-wide association study on covert MRI infarcts uncovered novel associations. Although replication of the association with top single nucleotide polymorphisms failed, possibly because of insufficient power, results in the black population sample are encouraging, and further efforts at replication are needed.

}, keywords = {African Americans, Aged, Brain, Brain Infarction, Cohort Studies, DNA Mutational Analysis, Female, Gene Frequency, Genetic Markers, Genetic Predisposition to Disease, Genetic Testing, Genetic Variation, Genome-Wide Association Study, Humans, Linkage Disequilibrium, Magnetic Resonance Imaging, Male, Middle Aged, Polymorphism, Single Nucleotide, Prospective Studies}, issn = {1524-4628}, doi = {10.1161/STROKEAHA.109.569194}, author = {Debette, Stephanie and Bis, Joshua C and Fornage, Myriam and Schmidt, Helena and Ikram, M Arfan and Sigurdsson, Sigurdur and Heiss, Gerardo and Struchalin, Maksim and Smith, Albert V and van der Lugt, Aad and DeCarli, Charles and Lumley, Thomas and Knopman, David S and Enzinger, Christian and Eiriksdottir, Gudny and Koudstaal, Peter J and DeStefano, Anita L and Psaty, Bruce M and Dufouil, Carole and Catellier, Diane J and Fazekas, Franz and Aspelund, Thor and Aulchenko, Yurii S and Beiser, Alexa and Rotter, Jerome I and Tzourio, Christophe and Shibata, Dean K and Tscherner, Maria and Harris, Tamara B and Rivadeneira, Fernando and Atwood, Larry D and Rice, Kenneth and Gottesman, Rebecca F and van Buchem, Mark A and Uitterlinden, Andr{\'e} G and Kelly-Hayes, Margaret and Cushman, Mary and Zhu, Yicheng and Boerwinkle, Eric and Gudnason, Vilmundur and Hofman, Albert and Romero, Jose R and Lopez, Oscar and van Duijn, Cornelia M and Au, Rhoda and Heckbert, Susan R and Wolf, Philip A and Mosley, Thomas H and Seshadri, Sudha and Breteler, Monique M B and Schmidt, Reinhold and Launer, Lenore J and Longstreth, W T} } @article {1343, title = {Genetic variants of the NOTCH3 gene in the elderly and magnetic resonance imaging correlates of age-related cerebral small vessel disease.}, journal = {Brain}, volume = {134}, year = {2011}, month = {2011 Nov}, pages = {3384-97}, abstract = {

Cerebral small vessel disease-related brain lesions such as white matter lesions and lacunes are common findings of magnetic resonance imaging in the elderly. These lesions are thought to be major contributors to disability in old age, and risk factors that include age and hypertension have been established. The radiological, histopathologic and clinical phenotypes of age-related cerebral small vessel disease remarkably resemble autosomal dominant arteriopathy with subcortical infarcts and leucoencephalopathy, which is caused by mutations in NOTCH3. We hypothesized that genetic variations in NOTCH3 also play a role in age-related cerebral small vessel disease. We directly sequenced all 33 exons, the promoter and 3{\textquoteright}-untranslated region of NOTCH3 in 195 participants with either coalescent white matter lesions or lacunes and compared the results to 82 randomly selected participants with no focal changes on magnetic resonance images in the Austrian Stroke Prevention Study. We detected nine common and 33 rare single nucleotide polymorphisms, of which 20 were novel. All common single nucleotide polymorphisms were genotyped in the entire cohort (n = 888), and four of them, rs1043994, rs10404382, rs10423702 and rs1043997, were associated significantly with both the presence and progression of white matter lesions. The association was confined to hypertensives, a result which we replicated in the Cohorts for Heart and Ageing Research in Genomic Epidemiology Consortium on an independent sample of 4773 stroke-free hypertensive elderly individuals of European descent (P = 0.04). The 33 rare single nucleotide polymorphisms were scattered over the NOTCH3 gene with three being located in the promoter region, 24 in exons (18 non-synonymous), three in introns and three in the 3{\textquoteright}-untranslated region. None of the single nucleotide polymorphisms affected a cysteine residue. Sorting Intolerant From Tolerant, PolyPhen2 analyses and protein structure simulation consistently predicted six of the non-synonymous single nucleotide polymorphisms (H170R, P496L, V1183M, L1518M, D1823N and V1952M) to be functional, with four being exclusively or mainly detected in subjects with severe white matter lesions. In four individuals with rare non-synonymous single nucleotide polymorphisms, we noted anterior temporal lobe hyperintensity, hyperintensity in the external capsule, lacunar infarcts or subcortical lacunar lesions. None of the observed abnormalities were specific to cerebral autosomal dominant arteriopathy with subcortical infarcts and leucoencephalopathy. This is the first comprehensive study investigating (i) the frequency of NOTCH3 variations in community-dwelling elderly and (ii) their effect on cerebral small vessel disease related magnetic resonance imaging phenotypes. We show that the NOTCH3 gene is highly variable with both common and rare single nucleotide polymorphisms spreading across the gene, and that common variants at the NOTCH3 gene increase the risk of age-related white matter lesions in hypertensives. Additional investigations are required to explore the biological mechanisms underlying the observed association.

}, keywords = {Aged, Aged, 80 and over, Alleles, Brain, Cerebral Small Vessel Diseases, Exons, Female, Follow-Up Studies, Genetic Association Studies, Genotype, Humans, Hypertension, Magnetic Resonance Imaging, Male, Middle Aged, Phenotype, Promoter Regions, Genetic, Prospective Studies, Receptor, Notch3, Receptors, Notch}, issn = {1460-2156}, doi = {10.1093/brain/awr252}, author = {Schmidt, Helena and Zeginigg, Marion and Wiltgen, Marco and Freudenberger, Paul and Petrovic, Katja and Cavalieri, Margherita and Gider, Pierre and Enzinger, Christian and Fornage, Myriam and Debette, Stephanie and Rotter, Jerome I and Ikram, Mohammad A and Launer, Lenore J and Schmidt, Reinhold} } @article {1298, title = {Genome-wide association studies of cerebral white matter lesion burden: the CHARGE consortium.}, journal = {Ann Neurol}, volume = {69}, year = {2011}, month = {2011 Jun}, pages = {928-39}, abstract = {

OBJECTIVE: White matter hyperintensities (WMHs) detectable by magnetic resonance imaging are part of the spectrum of vascular injury associated with aging of the brain and are thought to reflect ischemic damage to the small deep cerebral vessels. WMHs are associated with an increased risk of cognitive and motor dysfunction, dementia, depression, and stroke. Despite a significant heritability, few genetic loci influencing WMH burden have been identified.

METHODS: We performed a meta-analysis of genome-wide association studies (GWASs) for WMH burden in 9,361 stroke-free individuals of European descent from 7 community-based cohorts. Significant findings were tested for replication in 3,024 individuals from 2 additional cohorts.

RESULTS: We identified 6 novel risk-associated single nucleotide polymorphisms (SNPs) in 1 locus on chromosome 17q25 encompassing 6 known genes including WBP2, TRIM65, TRIM47, MRPL38, FBF1, and ACOX1. The most significant association was for rs3744028 (p(discovery) = 4.0 {\texttimes} 10(-9) ; p(replication) = 1.3 {\texttimes} 10(-7) ; p(combined) = 4.0 {\texttimes} 10(-15) ). Other SNPs in this region also reaching genome-wide significance were rs9894383 (p = 5.3 {\texttimes} 10(-9) ), rs11869977 (p = 5.7 {\texttimes} 10(-9) ), rs936393 (p = 6.8 {\texttimes} 10(-9) ), rs3744017 (p = 7.3 {\texttimes} 10(-9) ), and rs1055129 (p = 4.1 {\texttimes} 10(-8) ). Variant alleles at these loci conferred a small increase in WMH burden (4-8\% of the overall mean WMH burden in the sample).

INTERPRETATION: This large GWAS of WMH burden in community-based cohorts of individuals of European descent identifies a novel locus on chromosome 17. Further characterization of this locus may provide novel insights into the pathogenesis of cerebral WMH.

}, keywords = {Aged, Aged, 80 and over, Cerebral Cortex, Chromosomes, Human, Pair 17, Cognition Disorders, Cohort Studies, European Continental Ancestry Group, Female, Gene Frequency, Genetic Predisposition to Disease, Genome-Wide Association Study, Genotype, Humans, Leukoencephalopathies, Magnetic Resonance Imaging, Male, Middle Aged, Movement Disorders, Nerve Fibers, Myelinated, Polymorphism, Single Nucleotide, Residence Characteristics, RNA, Messenger}, issn = {1531-8249}, doi = {10.1002/ana.22403}, author = {Fornage, Myriam and Debette, Stephanie and Bis, Joshua C and Schmidt, Helena and Ikram, M Arfan and Dufouil, Carole and Sigurdsson, Sigurdur and Lumley, Thomas and DeStefano, Anita L and Fazekas, Franz and Vrooman, Henri A and Shibata, Dean K and Maillard, Pauline and Zijdenbos, Alex and Smith, Albert V and Gudnason, Haukur and de Boer, Renske and Cushman, Mary and Mazoyer, Bernard and Heiss, Gerardo and Vernooij, Meike W and Enzinger, Christian and Glazer, Nicole L and Beiser, Alexa and Knopman, David S and Cavalieri, Margherita and Niessen, Wiro J and Harris, Tamara B and Petrovic, Katja and Lopez, Oscar L and Au, Rhoda and Lambert, Jean-Charles and Hofman, Albert and Gottesman, Rebecca F and Garcia, Melissa and Heckbert, Susan R and Atwood, Larry D and Catellier, Diane J and Uitterlinden, Andr{\'e} G and Yang, Qiong and Smith, Nicholas L and Aspelund, Thor and Romero, Jose R and Rice, Kenneth and Taylor, Kent D and Nalls, Michael A and Rotter, Jerome I and Sharrett, Richey and van Duijn, Cornelia M and Amouyel, Philippe and Wolf, Philip A and Gudnason, Vilmundur and van der Lugt, Aad and Boerwinkle, Eric and Psaty, Bruce M and Seshadri, Sudha and Tzourio, Christophe and Breteler, Monique M B and Mosley, Thomas H and Schmidt, Reinhold and Longstreth, W T and DeCarli, Charles and Launer, Lenore J} }