Browsing by Subject "Heterozygote"

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Brain volumetric deficits in MAPT mutation carriers: a multisite study
    (Wiley, 2021) Chu, Stephanie A.; Flagan, Taru M.; Staffaroni, Adam M.; Jiskoot, Lize C.; Deng, Jersey; Spina, Salvatore; Zhang, Liwen; Sturm, Virginia E.; Yokoyama, Jennifer S.; Seeley, William W.; Papma, Janne M.; Geschwind, Dan H.; Rosen, Howard J.; Boeve, Bradley F.; Boxer, Adam L.; Heuer, Hilary W.; Forsberg, Leah K.; Brushaber, Danielle E.; Grossman, Murray; Coppola, Giovanni; Dickerson, Bradford C.; Bordelon, Yvette M.; Faber, Kelley; Feldman, Howard H.; Fields, Julie A.; Fong, Jamie C.; Foroud, Tatiana; Gavrilova, Ralitza H.; Ghoshal, Nupur; Graff-Radford, Neill R.; Hsiung, Ging-Yuek Robin; Huey, Edward D.; Irwin, David J.; Kantarci, Kejal; Kaufer, Daniel I.; Karydas, Anna M.; Knopman, David S.; Kornak, John; Kramer, Joel H.; Kukull, Walter A.; Lapid, Maria I.; Litvan, Irene; Mackenzie, Ian R. A.; Mendez, Mario F.; Miller, Bruce L.; Onyike, Chiadi U.; Pantelyat, Alexander Y.; Rademakers, Rosa; Ramos, Eliana Marisa; Roberson, Erik D.; Tartaglia, Maria Carmela; Tatton, Nadine A.; Toga, Arthur W.; Vetor, Ashley; Weintraub, Sandra; Wong, Bonnie; Wszolek, Zbigniew K.; ARTFL/LEFFTDS Consortium; Van Swieten, John C.; Lee, Suzee E.; Medical and Molecular Genetics, School of Medicine
    Objective: MAPT mutations typically cause behavioral variant frontotemporal dementia with or without parkinsonism. Previous studies have shown that symptomatic MAPT mutation carriers have frontotemporal atrophy, yet studies have shown mixed results as to whether presymptomatic carriers have low gray matter volumes. To elucidate whether presymptomatic carriers have lower structural brain volumes within regions atrophied during the symptomatic phase, we studied a large cohort of MAPT mutation carriers using a voxelwise approach. Methods: We studied 22 symptomatic carriers (age 54.7 ± 9.1, 13 female) and 43 presymptomatic carriers (age 39.2 ± 10.4, 21 female). Symptomatic carriers' clinical syndromes included: behavioral variant frontotemporal dementia (18), an amnestic dementia syndrome (2), Parkinson's disease (1), and mild cognitive impairment (1). We performed voxel-based morphometry on T1 images and assessed brain volumetrics by clinical subgroup, age, and mutation subtype. Results: Symptomatic carriers showed gray matter atrophy in bilateral frontotemporal cortex, insula, and striatum, and white matter atrophy in bilateral corpus callosum and uncinate fasciculus. Approximately 20% of presymptomatic carriers had low gray matter volumes in bilateral hippocampus, amygdala, and lateral temporal cortex. Within these regions, low gray matter volumes emerged in a subset of presymptomatic carriers as early as their thirties. Low white matter volumes arose infrequently among presymptomatic carriers. Interpretation: A subset of presymptomatic MAPT mutation carriers showed low volumes in mesial temporal lobe, the region ubiquitously atrophied in all symptomatic carriers. With each decade of age, an increasing percentage of presymptomatic carriers showed low mesial temporal volume, suggestive of early neurodegeneration.
  • Thumbnail Image
    Item
    Proteomics of brain, CSF, and plasma identifies molecular signatures for distinguishing sporadic and genetic Alzheimer's disease
    (American Association for the Advancement of Science, 2023) Sung, Yun Ju; Yang, Chengran; Norton, Joanne; Johnson, Matt; Fagan, Anne; Bateman, Randall J.; Perrin, Richard J.; Morris, John C.; Farlow, Martin R.; Chhatwal, Jasmeer P.; Schofield, Peter R.; Chui, Helena; Wang, Fengxian; Novotny, Brenna; Eteleeb, Abdallah; Karch, Celeste; Schindler, Suzanne E.; Rhinn, Herve; Johnson, Erik C. B.; Oh, Hamilton Se-Hwee; Rutledge, Jarod Evert; Dammer, Eric B.; Seyfried, Nicholas T.; Wyss-Coray, Tony; Harari, Oscar; Cruchaga, Carlos; Neurology, School of Medicine
    Proteomic studies for Alzheimer's disease (AD) are instrumental in identifying AD pathways but often focus on single tissues and sporadic AD cases. Here, we present a proteomic study analyzing 1305 proteins in brain tissue, cerebrospinal fluid (CSF), and plasma from patients with sporadic AD, TREM2 risk variant carriers, patients with autosomal dominant AD (ADAD), and healthy individuals. We identified 8 brain, 40 CSF, and 9 plasma proteins that were altered in individuals with sporadic AD, and we replicated these findings in several external datasets. We identified a proteomic signature that differentiated TREM2 variant carriers from both individuals with sporadic AD and healthy individuals. The proteins associated with sporadic AD were also altered in patients with ADAD, but with a greater effect size. Brain-derived proteins associated with ADAD were also replicated in additional CSF samples. Enrichment analyses highlighted several pathways, including those implicated in AD (calcineurin and Apo E), Parkinson's disease (α-synuclein and LRRK2), and innate immune responses (SHC1, ERK-1, and SPP1). Our findings suggest that combined proteomics across brain tissue, CSF, and plasma can be used to identify markers for sporadic and genetically defined AD.