Genome-wide analyses reveal a potential role for the MAPT, MOBP, and APOE loci in sporadic frontotemporal dementia.

Frontotemporal dementia (FTD) is the second most common cause of early-onset dementia after Alzheimer disease (AD). Efforts in the field mainly focus on familial forms of disease (fFTDs), while studies of the genetic etiology of sporadic FTD (sFTD) have been less common. In the current work, we analyzed 4,685 sFTD cases and 15,308 controls looking for common genetic determinants for sFTD. We found a cluster of variants at the MAPT (rs199443; p = 2.5 × 10-12, OR = 1.27) and APOE (rs6857; p = 1.31 × 10-12, OR = 1.27) loci and a candidate locus on chromosome 3 (rs1009966; p = 2.41 × 10-8, OR = 1.16) in the intergenic region between RPSA and MOBP, contributing to increased risk for sFTD through effects on expression and/or splicing in brain cortex of functionally relevant in-cis genes at the MAPT and RPSA-MOBP loci. The association with the MAPT (H1c clade) and RPSA-MOBP loci may suggest common genetic pleiotropy across FTD and progressive supranuclear palsy (PSP) (MAPT and RPSA-MOBP loci) and across FTD, AD, Parkinson disease (PD), and cortico-basal degeneration (CBD) (MAPT locus). Our data also suggest population specificity of the risk signals, with MAPT and APOE loci associations mainly driven by Central/Nordic and Mediterranean Europeans, respectively. This study lays the foundations for future work aimed at further characterizing population-specific features of potential FTD-discriminant APOE haplotype(s) and the functional involvement and contribution of the MAPT H1c haplotype and RPSA-MOBP loci to pathogenesis of sporadic forms of FTD in brain cortex.

Age-dependent effect of susceptibility factors on the risk of intracerebral haemorrhage: Multicenter Study on Cerebral Hemorrhage in Italy (MUCH-Italy).

OBJECTIVE: To investigate the age-dependent impact of traditional stroke risk factors on the occurrence of intracerebral haemorrhage (ICH). METHODS: We performed a case-control analysis, comparing consecutive patients with ICH with age-matched and sex-matched stroke-free controls, enrolled in the setting of the Multicenter Study on Cerebral Hemorrhage in Italy (MUCH-Italy) between 2002 and 2014 by multivariable logistic regression model within subgroups stratified by age quartiles (Q1-Q4). RESULTS: We analysed 3492 patients and 3492 controls. The impact of untreated hypertension on the risk of ICH was higher in the lower than in the upper age quartile (OR 11.64, 95% CI 7.68 to 17.63 in Q1 vs OR 6.05, 95% CI 3.09 to 11.85 in Q4 with intermediate ORs in Q2 and Q3), while the opposite trend was observed for untreated hypercholesterolaemia (OR 0.63, 95% CI 0.45 to 0.97 in Q1 vs OR 0.36, 95% CI 0.26 to 0.56 in Q4 with intermediate ORs in Q2 and Q3). The effect of untreated diabetes and excessive alcohol intake was detected only in the older age group (OR 3.63, 95% CI 1.22 to 10.73, and OR 1.69, 95% CI 1.13 to 2.51, respectively). CONCLUSIONS: Our findings provide evidence of age-dependent differences in the effects of susceptibility factors on the risk of ICH.

Brain Connectivity and Information-Flow Breakdown Revealed by a Minimum Spanning Tree-Based Analysis of MRI Data in Behavioral Variant Frontotemporal Dementia.

Brain functional disruption and cognitive shortfalls as consequences of neurodegeneration are among the most investigated aspects in current clinical research. Traditionally, specific anatomical and behavioral traits have been associated with neurodegeneration, thus directly translatable in clinical terms. However, these qualitative traits, do not account for the extensive information flow breakdown within the functional brain network that deeply affect cognitive skills. Behavioural variant Frontotemporal Dementia (bvFTD) is a neurodegenerative disorder characterized by behavioral and executive functions disturbances. Deviations from the physiological cognitive functioning can be accurately inferred and modeled from functional connectivity alterations. Although the need for unbiased metrics is still an open issue in imaging studies, the graph-theory approach applied to neuroimaging techniques is becoming popular in the study of brain dysfunction. In this work, we assessed the global connectivity and topological alterations among brain regions in bvFTD patients using a minimum spanning tree (MST) based analysis of resting state functional MRI (rs-fMRI) data. Whilst several graph theoretical methods require arbitrary criteria (including the choice of network construction thresholds and weight normalization methods), MST is an unambiguous modeling solution, ensuring accuracy, robustness, and reproducibility. MST networks of 116 regions of interest (ROIs) were built on wavelet correlation matrices, extracted from 41 bvFTD patients and 39 healthy controls (HC). We observed a global fragmentation of the functional network backbone with severe disruption of information-flow highways. Frontotemporal areas were less compact, more isolated, and concentrated in less integrated structures, respect to healthy subjects. Our results reflected such complex breakdown of the frontal and temporal areas at both intra-regional and long-range connections. Our findings highlighted that MST, in conjunction with rs-fMRI data, was an effective method for quantifying and detecting functional brain network impairments, leading to characteristic bvFTD cognitive, social, and executive functions disorders.