Cognitive decline in amyotrophic lateral sclerosis: Neuropathological substrate and genetic determinants.

Cognitive impairment and behavioral changes in amyotrophic lateral sclerosis (ALS) are now recognized as part of the disease. Whether it is solely related to the extent of TDP-43 pathology is currently unclear. We aim to evaluate the influence of age, genetics, neuropathological features, and concomitant pathologies on cognitive impairment in ALS patients.

Assessing circular RNAs in Alzheimer's disease and frontotemporal lobar degeneration.

A circular-transcriptome-wide study has recently linked differential expression of circular RNAs (circRNAs) in brain tissue with Alzheimer's disease (AD). We aimed at replicating the major findings in an independent series of sporadic and familial AD. We also included cases with frontotemporal lobar degeneration (FTLD), comprising brain specimens with TDP-43 aggregates (FTLD-TDP43) and samples that presented Tau accumulation (FTLD-Tau).

Genetic architecture of neurodegenerative dementias.

Molecular genetics has been an invaluable tool to help understand the molecular basis of neurodegenerative dementias. In this review, we provide an overview of the genetic architecture underlying some of the most prevalent causes of dementia, including Alzheimer's dementia, frontotemporal lobar degeneration, Lewy body dementia, and prion diseases. We also discuss the complexity of the human genome and how the novel technologies have revolutionized and accelerated the way we screen the variety of our DNA.

FAHN/SPG35: a narrow phenotypic spectrum across disease classifications.

The endoplasmic reticulum enzyme fatty acid 2-hydroxylase (FA2H) plays a major role in the formation of 2-hydroxy glycosphingolipids, main components of myelin. FA2H deficiency in mice leads to severe central demyelination and axon loss. In humans it has been associated with phenotypes from the neurodegeneration with brain iron accumulation (fatty acid hydroxylase-associated neurodegeneration, FAHN), hereditary spastic paraplegia (HSP type SPG35) and leukodystrophy (leukodystrophy with spasticity and dystonia) spectrum.

Systematic Screening of Ubiquitin/p62 Aggregates in Cerebellar Cortex Expands the Neuropathological Phenotype of the C9orf72 Expansion Mutation.

The neuropathological hallmark of the C9orf72 intronic hexanucleotide expansion in frontotemporal lobar degeneration (FTLD) and amyotrophic lateral sclerosis (ALS) is the presence of small ubiquitin/p62-positive and transactive response DNA binding protein 43 kDa (TDP-43)-negative cytoplasmic inclusions in several brain areas. The identification of this histopathological signature is highly predictive of an underlying mutation. In this study, we screened 1800 cases of the Barcelona IDIBAPS Brain Bank, independently of the clinical and final neuropathological diagnosis of the brain donor, for the presence of ubiquitin/p62-positive inclusions in the cerebellum (UPPI).

Distinct Clinical Features and Outcomes in Motor Neuron Disease Associated with Behavioural Variant Frontotemporal Dementia.

Aim: To determine the motor phenotype and outcome in a clinically ascertained group of patients with motor neuron disease (MND) and frontotemporal dementia (FTD).

Methods: This is an observational retrospective clinical study of patients fulfilling the clinical criteria for MND-FTD. A contemporary series of patients with amyotrophic lateral sclerosis (ALS) without dementia were included for comparison.

Analysis of known amyotrophic lateral sclerosis and frontotemporal dementia genes reveals a substantial genetic burden in patients manifesting both diseases not carrying the expansion mutation.

Unlabelled: Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) are part of a clinical, pathological and genetic continuum.

Objectives: The purpose of the present study was to assess the mutation burden that is present in patients with concurrent ALS and FTD (ALS/FTD) not carrying the chromosome 9 open reading frame 72 () hexanucleotide repeat expansion, the most important genetic cause in both diseases.

Methods: From an initial group of 973 patients with ALS, we retrospectively selected those patients fulfilling diagnostic criteria of concomitant ALS and FTD lacking the repeat expansion mutation in .

Exome sequencing in a consanguineous family clinically diagnosed with early-onset Alzheimer's disease identifies a homozygous CTSF mutation.

We have previously reported the whole genome genotyping analysis of 2 consanguineous siblings clinically diagnosed with early onset Alzheimer's disease (AD). In this analysis, we identified several large regions of homozygosity shared between both affected siblings, which we suggested could be candidate loci for a recessive genetic lesion underlying the early onset AD in these cases. We have now performed exome sequencing in one of these siblings and identified the potential cause of disease: the CTSF c.

Assessing the role of TUBA4A gene in frontotemporal degeneration.

The tubulin alpha 4a (TUBA4A) gene has been recently associated with amyotrophic lateral sclerosis. Interestingly, some of the mutation carriers were also diagnosed with frontotemporal degeneration (FTD) or mild cognitive impairment. With the aim to investigate the role of TUBA4A in FTD, we screened TUBA4A in a series of 814 FTD patients from Spain.