Non-carrier Family Members Research Articles

Connectome-based predictive modeling of brain pathology and cognition in Autosomal Dominant Alzheimer's Disease.

Autosomal Dominant Alzheimer's Disease (ADAD) through genetic mutations can result in near complete expression of the disease. Tracking AD pathology development in an ADAD cohort of Presenilin-1 (PSEN1) E280A carriers' mutation has allowed us to observe incipient tau tangles accumulation as early as 6 years prior to symptom onset. Resting-state functional Magnetic Resonance Imaging (fMRI) and Positron-Emission Tomography (PET) scans were acquired in a group of PSEN1 carriers (n=32) and non-carrier family members (n=35). We applied Connectome-based Predictive Modeling (CPM) to examine the relationship between the participant's functional connectome and their respective tau/amyloid-β levels and cognitive scores (word list recall). CPM models strongly predicted tau concentrations and cognitive scores within the carrier group. The connectivity patterns between the temporal cortex, default mode network, and other memory networks were the most informative of tau burden. These results indicate that resting-state fMRI methods can complement PET methods in early detection and monitoring of disease progression in ADAD.

The ENG/VEGFα Pathway Is Likely Affected by a Nonsense Variant of Endoglin (ENG)/CD105, Causing Hereditary Hemorrhagic Telangiectasia Type 1 (HHT1) in a Chinese Family.

Hereditary hemorrhagic telangiectasia (HHT), also called Rendu-Osler syndrome, is a group of rare genetic diseases characterized by autosomal dominance, multisystemic vascular dysplasia, and age-related penetrance. This includes arteriovenous malformations (AVMs) in the skin, brain, lung, liver, and mucous membranes. The correlations between the phenotype and genotype for HHT are not clear. An HHT Chinese pedigree was recruited. Whole exome sequencing (WES) analysis, Sanger verification, and co-segregation were conducted. Western blotting was performed for monitoring ENG/VEGFα signaling. As a result, a nonsense, heterozygous variant for ENG/CD105: c.G1169A:p. Trp390Ter of the proband with hereditary hemorrhagic telangiectasia type 1 (HHT1) was identified, which co-segregated with the disease in the M666 pedigree. Western blotting found that, compared with the normal levels associated with non-carrier family members, the ENG protein levels in the proband showed approximately a one-half decrease (47.4% decrease), while levels of the VEGFα protein, in the proband, showed approximately a one-quarter decrease (25.6% decrease), implying that ENG haploinsufficiency, displayed in the carrier of this variant, may affect VEGFα expression downregulation. Pearson and Spearman correlation analyses further supported TGFβ/ENG/VEGFα signaling, implying ENG regulation in the blood vessels. Thus, next-generation sequencing including WES should provide an accurate strategy for gene diagnosis, therapy, genetic counseling, and clinical management for rare genetic diseases including that in HHT1 patients.

Diagnostic accuracy of research criteria for prodromal frontotemporal dementia

BackgroundThe Genetic Frontotemporal Initiative Staging Group has proposed clinical criteria for the diagnosis of prodromal frontotemporal dementia (FTD), termed mild cognitive and/or behavioral and/or motor impairment (MCBMI). The objective of the study was to validate the proposed research criteria for MCBMI-FTD in a cohort of genetically confirmed FTD cases against healthy controls.MethodsA total of 398 participants were enrolled, 117 of whom were carriers of an FTD pathogenic variant with mild clinical symptoms, while 281 were non-carrier family members (healthy controls (HC)). A subgroup of patients underwent blood neurofilament light (NfL) levels and anterior cingulate atrophy assessment.ResultsThe core clinical criteria correctly classified MCBMI vs HC with an AUC of 0.79 (p < 0.001), while the addition of either blood NfL or anterior cingulate atrophy significantly increased the AUC to 0.84 and 0.82, respectively (p < 0.001). The addition of both markers further increased the AUC to 0.90 (p < 0.001).ConclusionsThe proposed MCBMI criteria showed very good classification accuracy for identifying the prodromal stage of FTD.

The MAPP Room Memory Test: Examining Contextual Memory Using a Novel Computerized Test in Cognitively-Unimpaired Individuals with Autosomal Dominant Alzheimer's Disease.

Contextual memory, the ability to remember spatial or temporal features related to an event, is affected in Alzheimer's disease (AD). There is a shortfall of tests that measure contextual memory. To evaluate visuospatial contextual memory, we developed a computerized cognitive test, the MAPP Room Memory Test, which requires participants to identify in which visual scene target items were previously presented. We hypothesized that cognitively-unimpaired carriers of an autosomal dominant AD mutation (Presenilin-1 E280A, n=15) would perform more poorly on this test than non-carrier family members (n=31). Compared to non-carriers, the carriers had significantly worse delayed room recognition. The results indicate that the MAPP Room Memory Test may be sensitive to subtle cognitive changes associated with risk of AD. Future studies with larger samples using the MAPP Room Memory Test and biomarkers are needed to examine whether this test may also be sensitive to the earliest pathological changes in preclinical AD.

33 Associations Between Long-Term Forgetting and Slow Wave Activity in Autosomal-Dominant Alzheimer’s Disease: Findings from the Colombia-Boston (COLBOS) Biomarker Study

Objective:Sleep contributes to memory retention and recall. Alzheimer’s disease (AD) patients experience decreased slow wave activity (SWA) during sleep. This decrease in SWA is associated with impaired memory consolidation (Lee et al., 2020). Long-term forgetting (LTF) over days or weeks has been linked to memory consolidation deficits and has been suggested as an early marker of AD that could be useful for identifying at-risk individuals for preclinical AD trials (Weston et al., 2018). Here, we examined associations between LTF and SWA in a sample of Presenilin-1 (PSEN1) E280A mutation carriers with autosomal dominant Alzheimer’s disease and non-carrier family members. Carriers of this mutation usually develop dementia in their forties (Fuller et al., 2019).Participants and Methods:Fourteen cognitively unimpaired PSEN1-E280A mutation carriers and sixteen age-matched non-carriers (mean age: 34.2 years) from the Colombia-Boston (COLBOS) biomarker study were included. Participants completed an overnight polysomnogram (PSG) and memory testing (NEUROPSI Word List) at 3-time points: 1) the night before PSG: immediate recall (Day1-ImmRecall) and a 20-minute delayed recall (Day1-DelayedRecall), 2) recall the following day (Day2-recall), and 3) recall one week later (Day7-recall). SWA was measured as the ratio 0. 6-1Hz/0.6-4Hz in frontopolar and frontotemporal regions and was calculated for sleep stages N2+N3 (slow wave sleep) based on an automated staging algorithm. Each participant’s LTF was calculated as the percent retention between Day 1 immediate recall and Day 7 recall (Butler, 2009). Mann-Whitney U tests were used to compare differences in recall, SWA, and LTF between groups. Spearman’s correlation was used to examine the associations between memory recall at different time points and SWA, as well as between LTF and SWA.Results:On Day 1, carriers had lower performance in immediate recall (p=0.02), compared to non-carriers, but there were no group differences in the 20-minute delayed recall. Carriers also recalled fewer words on Day 2 (p=0.03) and Day 7 (p=0.009) and had greater LTF (p=0.03). There were no group differences in SWA. In our overall sample, worse performance on word list delayed recall on Day 1, Day 2, and Day 7 was associated with less SWA across both frontotemporal (Day1: p=0.04, Day2: p=0.02, Day7: p=0.02) and frontopolar (all Ps&lt;0.01) regions. In carriers, only worse performance on Day 1 delayed recall was associated with lower SWA in the frontopolar region (r= 0.535; p=0.049). Memory recall on other days was not associated with SWA in any brain regions. Additionally, greater LTF was associated with less SWA across both frontopolar (r= 0.507; p=0.005) and frontotemporal regions (r= 0.463 p= 0.01).Conclusions:Preliminary findings suggest that long-term forgetting is associated with less slow- wave activity in preclinical autosomal dominant Alzheimer’s disease. These results also suggest that SWA may be related to pre-sleep learning and subsequent overnight memory consolidation processes. LTF testing may be useful in selecting individuals for preclinical AD trials. Future research on the impact of slow wave activity on LTF may be useful in identifying ways to enhance short- and long-term memory consolidation in individuals at greater risk for dementia.

26 Religious Stress Coping, Memory, and Markers of Brain Pathology in Individuals with Autosomal Dominant Alzheimer’s Disease from the Colombia-Boston Biomarker Study

Objective:High levels of stress may increase risk for Alzheimer’s disease (AD) dementia. Religious coping practices to deal with stress (i.e., prayer, having faith, attending religious services) may reduce risk of dementia. Studying religious stress coping in cognitively unimpaired individuals with autosomal-dominant AD (ADAD), who will develop dementia later in life, may inform us about the role of religious coping in modifying the clinical trajectory from preclinical to clinical stages of the disease. We examined religious stress coping in cognitively unimpaired mutation carriers from the world’s largest ADAD kindred and its relation to markers of brain pathology and memory.Participants and Methods:16 cognitively unimpaired Presenilin-1 E280A mutation carriers and 19 age and education-matched noncarrier family members from the Colombia-Boston (COLBOS) Biomarker Study were included. A subsample (n=26; 13 cognitively unimpaired carriers) underwent amyloid and tau PET imaging. Participants completed the Coping Strategies Questionnaire (CAE) that includes a subscale used to assess religious stress coping, where a higher score indicates more coping, and underwent memory testing using the Free and Cued Selective Reminding Test (FCSRT). The Geriatric Depression Scale (GDS) was used to assess depression. Mann-Whitney U tests were used to examine group differences in religious stress coping, brain pathology (i.e., cortical amyloid-beta, entorhinal and precuneus tau), memory, and depression. Nonparametric correlations were used to examine associations among religious stress coping, age, education, depression, memory, and pathology.Results:Carriers had poorer FCSRT immediate free recall than noncarriers (U=84.5, p=.024). There was no difference between groups in CAE religious stress coping, other FCSRT memory scores, nor GDS score (all p&gt;.05). Compared to non-carriers, carriers had more cortical amyloid (U=152.0, p&lt;.001) and more precuneus tau (U=123.0, p=.05). In carriers, religious stress coping was positively associated with education (r=.57, p=.022), FCSRT immediate free recall (a=.75, p&lt;.001), FCSRT cued recall (a=.50, p=.047), and FCSRT delayed recall (r=.52, p=.038). After controlling for education, religious stress coping remained positively associated with FCSRT immediate free recall (r=.65, p=.009), but not other FCSRT memory scores (all p&gt;.05). Religious stress coping was not associated with age or GDS score regardless of controlling for education (all p&gt;.05). In carriers, religious stress coping was negatively associated with entorhinal tau (r=-.73, p=.005) and precuneus tau burden (r=-.58, p=.037). The association between religious stress coping and entorhinal tau remained significant after controlling for education (r=-.67, p=.016), but not precuneus tau (p&gt;.05). Religious stress coping was not associated with cortical amyloid regardless of controlling for education in carriers (all p&gt;.05). None of the associations with brain pathology or memory were significant in the non-carrier group.Conclusions:Religious stress coping was associated with better memory performance and a low AD pathology burden in individuals at genetic risk for developing AD dementia. Future studies with independent and larger samples should further examine religious stress coping strategies and their associations with other AD-related biomarkers, as well as with other risk and protective factors to better understand their role at the preclinical and prodromal stages of Alzheimer’s disease.

4 Association Between Plasma Neurofilament Light Chain (NfL) and Non-Verbal Abstract Reasoning in a Colombian Cohort with Autosomal Dominant Alzheimer’s Disease

Objective:Neurofilament light chain (NfL), a plasma-based biomarker for neurodegeneration, is a promising marker for early Alzheimer disease (AD) detection in individuals at increased risk. We previously reported that Presenilin1 (PSEN1) E280A carriers have increased levels of plasma NfL relative to non-carrier family members twenty years before the onset of clinical symptoms. Abstract reasoning is one of the first cognitive abilities to deteriorate in AD. Here, we examined whether levels of plasma NfL were associated with non-verbal abstract reasoning performance in non-demented PSEN1-E280A carriers and non-carriers.Participants and Methods:A total of 798 members of the Colombian kindred with the PSEN1 E280A mutation (462 cognitively-unimpaired and 336 non-carriers; mean age= 34.02 (10.53), mean education= 8.23(4.60), 57% females and 43% males) were included in the study. Participants completed the Raven’s Progressive Matrices (RPM), Mini Mental State Examination (MMSE), and underwent blood sampling. Plasma NfL concentrations were measured with a single molecule array (Simoa) method. Mann-Whitney U test and education-adjusted Spearman partial correlation were used to examine group differences and associations between abstract reasoning performance and NfL levels.Results:Non-carriers were older (p&lt;.001) and had higher levels of education than carriers (p=.025). Compared to non-carriers, carriers had higher levels of NfL (p=.014), lower performance on the MMSE (p&lt;.001) and on the RPM (p=.001). In the whole sample, performance on the RPM was significantly associated with age (r= -.144, p&lt;.001), and MMSE score (r=.198, p&lt;.001). In carriers only, performance on the RPM was negatively associated with NfL levels (r=-.121, p=.009). This association was not significant in non-carriers.Conclusions:Our findings support the hypothesis that plasma NfL levels may be indicators of disease progression and early cognitive dysfunction in autosomal dominant AD. Future work with NfL, abstract reasoning and memory with larger samples across the preclinical/prodromal spectrum will allow a more comprehensive examination of these associations.

52 Memory Learning Curve and in vivo Brain Pathology in Non-Demented Individuals with Autosomal Dominant Alzheimer’s Disease: Findings from the Colombia-Boston Biomarker Study

Objective:Associative memory is impacted early in Alzheimer’s disease (AD). Poorer performance on associative memory tests has been related to greater amyloid and regional tau burden in preclinical AD. Our group previously examined the association of brain pathology and performance on the Free and Cued Selective Reminding Test (FCSRT) in Autosomal Dominant Alzheimer’s Disease (ADAD), finding that associative memory summary scores distinguished non-demented mutation carriers from non-carriers several years before clinical onset of cognitive impairment. In the current study, we examined whether FCSRT learning slopes were associated with brain pathology in a sample of ADAD carriers and non-carriers.Participants and Methods:There were 119 participants including 57 non-demented carriers of the Colombian kindred with the Presenilin1 E280A mutation and 62 non-carrier family members (mean age= 36.3, 60% female). Participants were administered the Mini-Mental State Examination (MMSE), a measure of global cognitive status, and the FCSRT, which consists of three trials in which participants are asked to freely recall the same list of 16 items. It is a well-established measure known to be sensitive to early changes in AD. A subsample of 69 participants (32 carriers and 37 non-carriers) underwent positron emission tomography (PET) to measure in vivo cortical amyloid-beta (Pittsburgh compound B, PiB), and regional tau (Flortaucipir, FTP) burden in entorhinal and precuneus regions, which are among the earliest sites of tau accumulation in this ADAD population. Mann Whitney U tests, Spearman correlations, and chi-square tests were used to examine group differences and relations among variables of interest. Learning slope was calculated by subtracting the number of items freely recalled in FCSRT Trial 1 from the number of items freely recalled in Trial 3.Results:Compared to non-carriers, carriers had greater cortical amyloid-ß and regional tau burden, lower MMSE scores (mean [SD]: carriers= 27.5 [2.7]; non-carriers= 28.8 [1.0]), and lower scores on total immediate/ delayed free/ cued recall scores on the FCSRT (all p&lt;.01). The groups did not differ on age, sex, or education level (all p&gt; 0.05). In the whole sample and in carriers only, we found that higher MMSE scores were associated with higher learning slope, meaning faster learning (whole group p= 0.25, p= 0.006; carriers p= 0.30, p=0.029). In the whole sample, we found that lower learning slope was associated with higher levels of amyloid (p=-.34, p=.006) and tau in the left, right, and bilateral precuneus region (p=-.43, p&lt;.001; p=-.46, p&lt;.001; p=-.45, p&lt;.001). In carriers only, lower learning slope was associated with higher tau burden in the left, right, and bilateral precuneus specifically (p=-.43, p=.017; p=-.48, p=.008; p=-.46, p=.010, respectively). No significant associations were found in non-carriers.Conclusions:These findings suggest that learning curves on an associative memory test may be sensitive to preclinical pathological changes in AD, specifically within the precuneus, a brain region known to be involved in cue reactivity, episodic memory retrieval, and mental imagery strategies. Future studies with larger samples are warranted to further examine associations between the FCSRT learning curves and regional tau accumulation in individuals with ADAD.

Depressive symptoms and hippocampal volume in autosomal dominant Alzheimer's disease.

Depressive symptoms are among early behavioral changes in Alzheimer's disease (AD); however, the relationship between neurodegeneration and depressive symptoms remains inconclusive. To better understand this relationship in preclinical AD, we examined hippocampal volume and depressive symptoms in cognitively unimpaired carriers of the presenilin-1 (PSEN1) E280A mutation for autosomal dominant AD. A total of 27 PSEN1 mutation carriers and 26 non-carrier family members were included. Linear regression was used to test the relationship between hippocampal volume and 15-item Geriatric Depression Scale. Carriers and non-carriers did not differ in depressive symptoms or hippocampal volume. Within carriers, lower hippocampal volume was associated with greater depressive symptoms, which remained significant after adjusting for age and cognition. This relationship was not significant in non-carriers. Hippocampal neurodegeneration may underlie depressive symptoms in preclinical autosomal dominant AD. These findings provide support for the utility of targeting depressive symptoms in AD prevention. We compared unimpaired autosomal dominant Alzheimer's disease (AD) mutation carriers and non-carriers. Carriers and non-carriers did not differ in severity of depressive symptoms. In carriers, hippocampal volume was inversely associated with depressive symptoms. Depressive symptoms may be a useful target in AD prevention.

Neuropsychological Characterization of Autosomal Recessive Intellectual Developmental Disorder 59 Associated with IMPA1 (MRT59).

Biallelic loss of function of IMPA1 causes autosomal recessive intellectual developmental disorder 59 (MRT59, OMIM #617323). MRT59 has been reported to present with significant intellectual disability and disruptive behavior, but little is known about the neurocognitive pattern of those patients. Thus, the aims of this study were: (1) to assess the cognitive profile of these patients, and (2) to evaluate their functional dependence levels. Eighteen adults, aged 37 to 89 years, participated in this study: nine MRT59 patients, five heterozygous carriers and four non-carrier family members. All of them were from a consanguineous family living in Northeast Brazil. All IMPA1 patients had the (c.489_493dupGGGCT) pathogenic variant in homozygosis. For cognitive assessment, the WASI battery was applied in nine MRT59 patients and compared to heterozygous carriers and non-carrier family members. Functional dependence was evaluated using the functional independence measure (FIM). Patients showed moderate to severe intellectual disability and severe functional disabilities. Heterozygous carriers did not differ from non-carriers. MRT59 patients should be followed up by health professionals in an interdisciplinary way to understand their cognitive disabilities and functional needs properly.

Associations of category fluency clustering performance with in vivo brain pathology in autosomal dominant Alzheimer's disease.

Alzheimer's disease (AD) is known to impact semantic access, which is frequently evaluated using the Category Fluency (Animals) test. Recent studies have suggested that in addition to overall category fluency scores (total number of words produced over time), poor clustering could signal AD-related cognitive difficulties. In this study, we examined the association between category fluency clustering performance (i.e., stating words sequentially that are all contained within a subcategory, such as domestic animals) and brain pathology in individuals with autosomal dominant Alzheimer's disease (ADAD). A total of 29 non-demented carriers of the Presenilin1 E280A ADAD mutation and 32 noncarrier family members completed the category fluency test (Animals) and the Mini-Mental State Examination (MMSE). The participants also underwent positron emission tomography (PET) scans to evaluate in vivo amyloid-beta in the neocortex and tau in medial temporal lobe regions. Differences between carriers and noncarriers on cognitive tests were assessed with Mann-Whitney tests; associations between cognitive test performance and brain pathology were assessed with Spearman correlations. Animal fluency scores did not differ between carriers and noncarriers. Carriers, however, showed a stronger association between animal fluency clustering and in vivo AD brain pathology (neocortical amyloid and entorhinal tau) relative to noncarriers. This study indicates that using category fluency clustering, but not total score, is related to AD pathophysiology in the preclinical and early stages of the disease.

Plasma inflammation for predicting phenotypic conversion and clinical progression of autosomal dominant frontotemporal lobar degeneration

BackgroundMeasuring systemic inflammatory markers may improve clinical prognosis and help identify targetable pathways for treatment in patients with autosomal dominant forms of frontotemporal lobar degeneration (FTLD).MethodsWe measured plasma concentrations of...

Memory for Semantically Related Objects Differentiates Cognitively Unimpaired Autosomal Dominant Mutation Carriers from Non-Carrier Family Members.

Early cognitive changes due to Alzheimer's disease (AD) include difficulties in semantic access and working memory. Using a computerized cognitive test developed by our group, called the Memory for Semantically Related Objects test (MESERO), we evaluated if cognitively unimpaired carriers of an autosomal dominant AD (ADAD) mutation performed worse on this test than non-carrier family members. 35 cognitively unimpaired ADAD mutation carriers and 26 non-carrier family members from a Colombian ADAD cohort took the MESERO on a laptop computer. Cognitively unimpaired ADAD carriers had significantly worse MESERO total scores than non-carrier family members, driven by worse performance in semantically-related object sets; group performances did not differ on semantically unrelated object sets. Findings suggest that MESERO performance may be sensitive to subtle cognitive changes associated with AD. Future MESERO research should examine performances between healthy older adults and people at risk for sporadic AD.

Plasma p-tau217 predicts in vivo brain pathology and cognition in autosomal dominant Alzheimer's disease.

Plasma-measured tau phosphorylated at threonine 217 (p-tau217) is a potential non-invasive biomarker of Alzheimer's disease (AD). We investigated whether plasma p-tau217 predicts subsequent cognition and positron emission tomography (PET) markers of pathology in autosomal dominant AD. We analyzed baseline levels of plasma p-tau217 and its associations with amyloid PET, tau PET, and word list delayed recall measured 7.61 years later in non-demented age- and education-matched presenilin-1 E280A carriers (n=24) and non-carrier (n=20) family members. Carriers had higher plasma p-tau217 levels than non-carriers. Baseline plasma p-tau217 was associated with subsequent amyloid and tau PET pathology levels and cognitive function. Our findings suggest that plasma p-tau217 predicts subsequent brain pathological burden and memory performance in presenilin-1 E280A carriers. These results provide support for plasma p-tau217 as a minimally invasive diagnostic and prognostic biomarker for AD, with potential utility in clinical practice and trials. Non-demented presenilin-1 E280A carriers have higher plasma tau phosphorylated at threonine 217 (p-tau217) than do age-matched non-carriers. Higher baseline p-tau217 is associated with greater future amyloid positron emission tomography (PET) pathology burden. Higher baseline p-tau217 is associated with greater future tau PET pathology burden. Higher baseline p-tau217 is associated with worse future memory performance.

Olfactory Function and Markers of Brain Pathology in Non-Demented Individuals with Autosomal Dominant Alzheimer's Disease.

Olfactory dysfunction is one of the earliest signs of Alzheimer's disease (AD), highlighting its potential use as a biomarker for early detection. It has also been linked to progression from mild cognitive impairment (MCI) to dementia. To study olfactory function and its associations with markers of AD brain pathology in non-demented mutation carriers of an autosomal dominant AD (ADAD) mutation and non-carrier family members. We analyzed cross-sectional data from 16 non-demented carriers of the Presenilin1 E280A ADAD mutation (mean age [SD]: 40.1 [5.3], and 19 non-carrier family members (mean age [SD]: 36.0 [5.5]) from Colombia, who completed olfactory and cognitive testing and underwent amyloid and tau positron emission tomography (PET) imaging. Worse olfactory identification performance was associated with greater age in mutation carriers (r = -0.52 p = 0.037). In carriers, worse olfactory identification performance was related to worse MMSE scores (r = 0.55, p = 0.024) and CERAD delayed recall (r = 0.63, p = 0.007) and greater cortical amyloid-β (r = -0.53, p = 0.042) and tau pathology burden (entorhinal: r = -0.59, p = 0.016; inferior temporal: r = -0.52, p = 0.038). Worse performance on olfactory identification tasks was associated with greater age, a proxy for disease progression in this genetically vulnerable ADAD cohort. In addition, this is the first study to report olfactory dysfunction in ADAD mutation carriers with diagnosis of MCI and its correlation with abnormal accumulation of tau pathology in the entorhinal region. Taken together, our findings suggest that olfactory dysfunction has promise as an early marker of brain pathology and future risk for dementia.

Generation of human induced pluripotent stem cell (iPSC) lines derived from five patients carrying the pathogenic phospholamban-R14del (PLN-R14del) variant and three non-carrier family members

The R14del pathogenic variant in the phospholamban (PLN) gene (PLN-R14del), has been identified in families with hereditary cardiomyopathy, including dilated and arrhythmogenic cardiomyopathies. Here we have generated human iPSC lines from five PLN-R14del carriers and three non-carrier family members. Peripheral blood mononuclear cells (PBMC) were obtained from the eight individuals and reprogrammed using Sendai viral vector system carrying the Yamanaka factors. All eight lines show typical iPSC morphology, normal karyotype, high expression of pluripotency markers, and possess the ability to differentiate into all three germ layers. These lines represent valuable resources for studying the pathophysiological mechanisms of PLN-R14del associated cardiomyopathy.

Stem cell models of primary tauopathies reveal defects in synaptic function.

Primary tauopathies are characterized neuropathologically by inclusions containing abnormal forms of the microtubule-associated protein tau (MAPT) and clinically by diverse neuropsychiatric, cognitive, and motor impairments. Autosomal dominant mutations in the MAPT gene cause heterogeneous forms of frontotemporal lobar degeneration with tauopathy (FTLD-Tau). Common and rare variants in the MAPT gene increase the risk for sporadic FTLD-Tau, including progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD). We generated a collection of fibroblasts from 140 MAPT mutation/risk variant carriers, PSP, CBD, and cognitively normal controls; 31 induced pluripotent stem cell (iPSC) lines from MAPT mutation carriers, non-carrier family members, and autopsy-confirmed PSP patients; 33 genome engineered iPSCs that were corrected or mutagenized; and forebrain neural progenitor cells (NPCs). To begin to identify the genes and pathways that are dysregulated in primary tauopathies, we performed transcriptomic analyses in induced pluripotent stem cell (iPSC)-derived neurons carrying MAPT p.R406W and CRISPR/Cas9-corrected isogenic controls. We found that the expression of the MAPT p.R406W mutation was sufficient to create a significantly different transcriptomic profile compared with that of the isogeneic controls and to cause the differential expression of 328 genes. Sixty-one of these genes were also differentially expressed between MAPT p.R406W carriers and control brains. Twelve of these genes are also differentially expressed between PSP and control brains. Together, these genes are enriched for pathways involved in GABA-mediated signaling and synaptic function, which may contribute to the pathogenesis of FTLD-tau and other primary tauopathies. Here, we present a resource of fibroblasts, iPSCs, and NPCs with comprehensive clinical histories that can be accessed by the scientific community for disease modeling and development of novel therapeutics for tauopathies.

Characterizing Sleep Problems in 16p11.2 Deletion and Duplication.

Studies of 16p11.2 copy number variants (CNVs) provide an avenue to identify mechanisms of impairment and develop targeted treatments for individuals with neurodevelopmental disorders. 16p11.2 deletion and duplication phenotypes are currently being ascertained; however, sleep disturbances are minimally described. In this study, we examine sleep disturbance in a well-characterized national sample of 16p11.2 CNVs, the Simons Foundation Autism Research Initiative (SFARI) database of youth and adults (n = 692). Factor analyses and multilevel models of derived sleep questionnaires for youth (n = 345) and adults (n = 347) indicate that 16p11.2 carriers show elevated sleep disturbance relative to community controls. Non-carrier family members also show elevated sleep disturbance. However, sleep duration does not differ between carriers and controls. Further studies of sleep in 16p11.2 are needed.

Cortical Frontoparietal Network Dysfunction in CHMP2B-Frontotemporal Dementia.

A rare cause of inherited frontotemporal dementia (FTD) is a mutation in the CHMP2B gene on chromosome 3 leading to the autosomal dominantly inherited FTD (CHMP2B-FTD). Since CHMP2B-FTD is clinically well-characterized, and patients show a distinct pattern of executive dysfunction, the condition offers possible insight in the early electroencephalographic (EEG) changes in the cortical networks. Specifically, EEG microstate analysis parses the EEG signals into topographies believed to represent discrete network activations. We investigated the EEG dynamics in patients with symptomatic CHMP2B-FTD (n = 5) as well as pre-symptomatic mutation carriers (n = 5) compared to non-carrier family members (n = 6). The data was parsed into four archetypal microstates and global power was calculated. A trend was found for lower occurrence in microstate D in CHMP2B-FTD (p-value = 0.177, F-value = 2.036). Patients with recent symptom onset (<1 year) showed an increased duration of microstate D, whereas patients who had been symptomatic for longer periods (>2 years) showed decreased duration. Patients with CHMP2B-FTD present with executive dysfunction, and microstate D has previously been shown to be associated with the fronto-parietal network. The biphasic pattern may represent the pathophysiological changes in brain dynamics during neurodegeneration, which may apply to other neurodegenerative diseases.

Subjective Cognitive Decline and its Relation to Verbal Memory and Sex in Cognitively Unimpaired Individuals from a Colombian Cohort with Autosomal-Dominant Alzheimer's Disease.

Subjective Cognitive Decline (SCD) may be an early indicator of risk for Alzheimer's disease (AD). Findings regarding sex differences in SCD are inconsistent. Studying sex differences in SCD within cognitively unimpaired individuals with autosomal-dominant AD (ADAD), who will develop dementia, may inform sex-related SCD variations in preclinical AD. We examined sex differences in SCD within cognitively unimpaired mutation carriers from the world's largest ADAD kindred and sex differences in the relationship between SCD and memory performance. We included 310 cognitively unimpaired Presenilin-1 (PSEN-1) E280A mutation carriers (51% females) and 1998 noncarrier family members (56% females) in the study. Subjects and their study partners completed SCD questionnaires and the CERAD word list delayed recall test. ANCOVAs were conducted to examine group differences in SCD, sex, and memory performance. In carriers, partial correlations were used to examine associations between SCD and memory performance covarying for education. Females in both groups had greater self-reported and study partner-reported SCD than males (all p < 0.001). In female mutation carriers, greater self-reported (p = 0.02) and study partner-reported SCD (p < 0.001) were associated with worse verbal memory. In male mutation carriers, greater self-reported (p = 0.03), but not study partner-reported SCD (p = 0.11) was associated with worse verbal memory. Study partner-reported SCD may be a stronger indicator of memory decline in females versus males in individuals at risk for developing dementia. Future studies with independent samples and preclinical trials should consider sex differences when recruiting based on SCD criteria.