Browsing by Author "Nuytemans, Karen"

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    A locus at 19q13.31 significantly reduces the ApoE ε4 risk for Alzheimer's Disease in African Ancestry
    (Public Library of Science, 2022-07-05) Rajabli, Farid; Beecham, Gary W.; Hendrie, Hugh C.; Baiyewu, Olusegun; Ogunniyi, Adesola; Gao, Sujuan; Kushch, Nicholas A.; Lipkin-Vasquez, Marina; Hamilton-Nelson, Kara L.; Young, Juan I.; Dykxhoorn, Derek M.; Nuytemans, Karen; Kunkle, Brian W.; Wang, Liyong; Jin, Fulai; Liu, Xiaoxiao; Feliciano-Astacio, Briseida E.; Alzheimer’s Disease Sequencing Project; Alzheimer’s Disease Genetic Consortium; Schellenberg, Gerard D.; Dalgard, Clifton L.; Griswold, Anthony J.; Byrd, Goldie S.; Reitz, Christiane; Cuccaro, Michael L.; Haines, Jonathan L.; Pericak-Vance, Margaret A.; Vance, Jeffery M.; Psychiatry, School of Medicine
    African descent populations have a lower Alzheimer disease risk from ApoE ε4 compared to other populations. Ancestry analysis showed that the difference in risk between African and European populations lies in the ancestral genomic background surrounding the ApoE locus (local ancestry). Identifying the mechanism(s) of this protection could lead to greater insight into the etiology of Alzheimer disease and more personalized therapeutic intervention. Our objective is to follow up the local ancestry finding and identify the genetic variants that drive this risk difference and result in a lower risk for developing Alzheimer disease in African ancestry populations. We performed association analyses using a logistic regression model with the ApoE ε4 allele as an interaction term and adjusted for genome-wide ancestry, age, and sex. Discovery analysis included imputed SNP data of 1,850 Alzheimer disease and 4,331 cognitively intact African American individuals. We performed replication analyses on 63 whole genome sequenced Alzheimer disease and 648 cognitively intact Ibadan individuals. Additionally, we reproduced results using whole-genome sequencing of 273 Alzheimer disease and 275 cognitively intact admixed Puerto Rican individuals. A further comparison was done with SNP imputation from an additional 8,463 Alzheimer disease and 11,365 cognitively intact non-Hispanic White individuals. We identified a significant interaction between the ApoE ε4 allele and the SNP rs10423769_A allele, (β = -0.54,SE = 0.12,p-value = 7.50x10-6) in the discovery data set, and replicated this finding in Ibadan (β = -1.32,SE = 0.52,p-value = 1.15x10-2) and Puerto Rican (β = -1.27,SE = 0.64,p-value = 4.91x10-2) individuals. The non-Hispanic Whites analyses showed an interaction trending in the "protective" direction but failing to pass a 0.05 significance threshold (β = -1.51,SE = 0.84,p-value = 7.26x10-2). The presence of the rs10423769_A allele reduces the odds ratio for Alzheimer disease risk from 7.2 for ApoE ε4/ε4 carriers lacking the A allele to 2.1 for ApoE ε4/ε4 carriers with at least one A allele. This locus is located approximately 2 mB upstream of the ApoE locus, in a large cluster of pregnancy specific beta-1 glycoproteins on chromosome 19 and lies within a long noncoding RNA, ENSG00000282943. This study identified a new African-ancestry specific locus that reduces the risk effect of ApoE ε4 for developing Alzheimer disease. The mechanism of the interaction with ApoEε4 is not known but suggests a novel mechanism for reducing the risk for ε4 carriers opening the possibility for potential ancestry-specific therapeutic intervention.
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    Absence of C9ORF72 expanded or intermediate repeats in autopsy-confirmed Parkinson's disease
    (Wiley, 2014-05) Nuytemans, Karen; Inchausti, Vanessa; Beecham, Gary W.; Wang, Liyong; Dickson, Dennis W.; Trojanowski, John Q.; Lee, Virginia M.-Y.; Mash, Deborah C.; Frosch, Matthew P.; Foroud, Tatiana M.; Honig, Lawrence S.; Montine, Thomas J.; Dawson, Ted M.; Martin, Eden R.; Scott, William K.; Vance, Jeffery M.; Medical & Molecular Genetics, School of Medicine
    BACKGROUND: We have reported that intermediate repeat lengths of the C9ORF72 repeat are a risk factor for Parkinson's disease (PD) in a clinically diagnosed data set. Because 10% to 25% of clinically diagnosed PD have different diagnoses upon autopsy, we hypothesized that this may reflect phenotypic heterogeneity or concomitant pathology of other neurodegenerative disorders. METHODS: We screened 488 autopsy-confirmed PD cases for expansion haplotype tag rs3849942T. In 196 identified haplotype carriers, the C9ORF72 repeat was genotyped using the repeat-primed polymerase chain reaction assay. RESULTS: No larger (intermediate or expanded) repeats were found in these autopsy-confirmed PD samples. This absence of larger repeats is significantly different from the frequency in clinically diagnosed datasets (P = 0.002). CONCLUSIONS: Our results suggest that expanded or intermediate C9ORF72 repeats in clinically diagnosed PD or parkinsonism might be an indication of heterogeneity in clinically diagnosed PD cases. Further studies are needed to elucidate the potential contribution of the C9ORF72 repeat to autopsy-confirmed PD.
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    Genomewide Association Studies of LRRK2 Modifiers of Parkinson's Disease
    (Wiley, 2021-07) Lai, Dongbing; Alipanahi, Babak; Fontanillas, Pierre; Schwantes, Tae-Hwi; Aasly, Jan; Alcalay, Roy N.; Beecham, Gary W.; Berg, Daniela; Bressman, Susan; Brice, Alexis; Brockman, Kathrin; Clark, Lorraine; Cookson, Mark; Das, Sayantan; Van Deerlin, Vivianna; Follett, Jordan; Farrer, Matthew J.; Trinh, Joanne; Gasser, Thomas; Goldwurm, Stefano; Gustavsson, Emil; Klein, Christine; Lang, Anthony E.; Langston, J. William; Latourelle, Jeanne; Lynch, Timothy; Marder, Karen; Marras, Connie; Martin, Eden R.; McLean, Cory Y.; Mejia-Santana, Helen; Molho, Eric; Myers, Richard H.; Nuytemans, Karen; Ozelius, Laurie; Payami, Haydeh; Raymond, Deborah; Rogaeva, Ekaterina; Rogers, Michael P.; Ross, Owen A.; Samii, Ali; Saunders-Pullman, Rachel; Schüle, Birgitt; Schulte, Claudia; Scott, William K.; Tanner, Caroline; Tolosa, Eduardo; Tomkins, James E.; Vilas, Dolores; Trojanowski, John Q.; Uitti, Ryan; Vance, Jeffery M.; Visanji, Naomi P.; Wszolek, Zbigniew K.; Zabetian, Cyrus P.; Mirelman, Anat; Giladi, Nir; Urtreger, Avi Orr; Cannon, Paul; Fiske, Brian; Foroud, Tatiana; Medical and Molecular Genetics, School of Medicine
    Objective: The aim of this study was to search for genes/variants that modify the effect of LRRK2 mutations in terms of penetrance and age-at-onset of Parkinson's disease. Methods: We performed the first genomewide association study of penetrance and age-at-onset of Parkinson's disease in LRRK2 mutation carriers (776 cases and 1,103 non-cases at their last evaluation). Cox proportional hazard models and linear mixed models were used to identify modifiers of penetrance and age-at-onset of LRRK2 mutations, respectively. We also investigated whether a polygenic risk score derived from a published genomewide association study of Parkinson's disease was able to explain variability in penetrance and age-at-onset in LRRK2 mutation carriers. Results: A variant located in the intronic region of CORO1C on chromosome 12 (rs77395454; p value = 2.5E-08, beta = 1.27, SE = 0.23, risk allele: C) met genomewide significance for the penetrance model. Co-immunoprecipitation analyses of LRRK2 and CORO1C supported an interaction between these 2 proteins. A region on chromosome 3, within a previously reported linkage peak for Parkinson's disease susceptibility, showed suggestive associations in both models (penetrance top variant: p value = 1.1E-07; age-at-onset top variant: p value = 9.3E-07). A polygenic risk score derived from publicly available Parkinson's disease summary statistics was a significant predictor of penetrance, but not of age-at-onset. Interpretation: This study suggests that variants within or near CORO1C may modify the penetrance of LRRK2 mutations. In addition, common Parkinson's disease associated variants collectively increase the penetrance of LRRK2 mutations. ANN NEUROL 2021;90:82-94.
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    Identification of TMEM230 mutations in familial Parkinson's disease
    (Nature Research, 2016-07) Deng, Han-Xiang; Shi, Yong; Yang, Yi; Ahmeti, Kreshnik B.; Miller, Nimrod; Huang, Cao; Cheng, Lijun; Zhai, Hong; Deng, Sheng; Nuytemans, Karen; Corbett, Nicola J.; Kim, Myung Jong; Deng, Hao; Tang, Baisha; Yang, Ziquang; Xu, Yanming; Chen, Piao; Huang, Bo; Gao, Xiao-Ping; Song, Zhi; Liu, Zhenhua; Fecto, Faisal; Siddique, Nailah; Foroud, Tatiana; Jankovic, Joseph; Ghetti, Bernardino; Nicholson, Daniel A.; Krainc, Dimitri; Melen, Onur; Vance, Jeffery M.; Pericak-Vance, Margaret A.; Ma, Yong-Chao; Rajput, Ali H.; Siddique, Teepu; Medical and Molecular Genetics, School of Medicine
    Parkinson's disease is the second most common neurodegenerative disorder without effective treatment. It is generally sporadic with unknown etiology. However, genetic studies of rare familial forms have led to the identification of mutations in several genes, which are linked to typical Parkinson's disease or parkinsonian disorders. The pathogenesis of Parkinson's disease remains largely elusive. Here we report a locus for autosomal dominant, clinically typical and Lewy body-confirmed Parkinson's disease on the short arm of chromosome 20 (20pter-p12) and identify TMEM230 as the disease-causing gene. We show that TMEM230 encodes a transmembrane protein of secretory/recycling vesicles, including synaptic vesicles in neurons. Disease-linked TMEM230 mutants impair synaptic vesicle trafficking. Our data provide genetic evidence that a mutant transmembrane protein of synaptic vesicles in neurons is etiologically linked to Parkinson's disease, with implications for understanding the pathogenic mechanism of Parkinson's disease and for developing rational therapies.