Browsing by Author "Tanner, Caroline"

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    Dopamine transporter imaging predicts clinically-defined α-synucleinopathy in REM sleep behavior disorder
    (Wiley, 2021) Chahine, Lana M.; Brumm, Michael C.; Caspell-Garcia, Chelsea; Oertel, Wolfgang; Mollenhauer, Brit; Amara, Amy; Fernandez-Arcos, Ana; Tolosa, Eduardo; Simonet, Cristina; Hogl, Birgit; Videnovic, Aleksandar; Hutten, Samantha J.; Tanner, Caroline; Weintraub, Daniel; Burghardt, Elliot; Coffey, Christopher; Cho, Hyunkeun R.; Kieburtz, Karl; Poston, Kathleen L.; Merchant, Kalpana; Galasko, Douglas; Foroud, Tatiana; Siderowf, Andrew; Marek, Kenneth; Simuni, Tanya; Iranzo, Alex; Medical and Molecular Genetics, School of Medicine
    Introduction: Individuals with idiopathic rapid eye movement sleep behavior disorder (iRBD) are at high risk for a clinical diagnosis of an α-synucleinopathy (aSN). They could serve as a key population for disease-modifying trials. Abnormal dopamine transporter (DAT) imaging is a strong candidate biomarker for risk of aSN diagnosis in iRBD. Our primary objective was to identify a quantitative measure of DAT imaging that predicts diagnosis of clinically-defined aSN in iRBD. Methods: The sample included individuals with iRBD, early Parkinson's Disease (PD), and healthy controls (HC) enrolled in the Parkinson Progression Marker Initiative, a longitudinal, observational, international, multicenter study. The iRBD cohort was enriched with individuals with abnormal DAT binding at baseline. Motor and nonmotor measures were compared across groups. DAT specific binding ratios (SBR) were used to calculate the percent of expected DAT binding for age and sex using normative data from HCs. Receiver operative characteristic analyses identified a baseline DAT binding cutoff that distinguishes iRBD participants diagnosed with an aSN in follow-up versus those not diagnosed. Results: The sample included 38 with iRBD, 205 with PD, and 92 HC who underwent DAT-SPECT at baseline. Over 4.7 years of mean follow-up, 14 (36.84%) with iRBD were clinically diagnosed with aSN. Risk of aSN diagnosis was significantly elevated among those with baseline putamen SBR ≤ 48% of that expected for age and sex, relative to those above this cutoff (hazard ratio = 17.8 [95%CI: 3.79-83.3], P = 0.0003). Conclusion: We demonstrate the utility of DAT SBR to identify individuals with iRBD with increased short-term risk of an aSN diagnosis.
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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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    Longitudinal clinical and biomarker characteristics of non-manifesting LRRK2 G2019S carriers in the PPMI cohort
    (Springer, 2022-10-22) Simuni, Tanya; Merchant, Kalpana; Brumm, Michael C.; Cho, Hyunkeun; Caspell-Garcia, Chelsea; Coffey, Christopher S.; Chahine, Lana M.; Alcalay, Roy N.; Nudelman, Kelly; Foroud, Tatiana; Mollenhauer, Brit; Siderowf, Andrew; Tanner, Caroline; Iwaki, Hirotaka; Sherer, Todd; Marek, Kenneth; Parkinson’s Progression Marker Initiative Authors; Medical and Molecular Genetics, School of Medicine
    We examined 2-year longitudinal change in clinical features and biomarkers in LRRK2 non-manifesting carriers (NMCs) versus healthy controls (HCs) enrolled in the Parkinson’s Progression Markers Initiative (PPMI). We analyzed 2-year longitudinal data from 176 LRRK2 G2019S NMCs and 185 HCs. All participants were assessed annually with comprehensive motor and non-motor scales, dopamine transporter (DAT) imaging, and biofluid biomarkers. The latter included cerebrospinal fluid (CSF) Abeta, total tau and phospho-tau; serum urate and neurofilament light chain (NfL); and urine bis(monoacylglycerol) phosphate (BMP). At baseline, LRRK2 G2019S NMCs had a mean (SD) age of 62 (7.7) years and were 56% female. 13% had DAT deficit (defined as <65% of age/sex-expected lowest putamen SBR) and 11% had hyposmia (defined as ≤15th percentile for age and sex). Only 5 of 176 LRRK2 NMCs developed PD during follow-up. Although NMCs scored significantly worse on numerous clinical scales at baseline than HCs, there was no longitudinal change in any clinical measures over 2 years or in DAT binding. There were no longitudinal differences in CSF and serum biomarkers between NMCs and HCs. Urinary BMP was significantly elevated in NMCs at all time points but did not change longitudinally. Neither baseline biofluid biomarkers nor the presence of DAT deficit correlated with 2-year change in clinical outcomes. We observed no significant 2-year longitudinal change in clinical or biomarker measures in LRRK2 G2019S NMCs in this large, well-characterized cohort even in the participants with baseline DAT deficit. These findings highlight the essential need for further enrichment biomarker discovery in addition to DAT deficit and longer follow-up to enable the selection of NMCs at the highest risk for conversion to enable future prevention clinical trials.