Plasma Neurodegenerative Biomarkers in Cognitively Preserved Nonagenarians.

Plasma biomarkers represent promising tools for the screening and diagnosis of patients with neurodegenerative conditions. However, it is crucial to account for the effects of aging on biomarker profiles, especially in the oldest segments of the population. Additionally, biomarkers in this sample can offer in vivo insights into the physiological mechanisms underlying brain aging while concomitantly supporting cognitive preservation.

Gene Variants in AD Patients and Their Relationship to CSF Protein Levels.

ADAM10 is the main α-secretase acting in the non-amyloidogenic processing of APP. We hypothesized that certain rare variants could increase the risk for AD by conferring the age-related downregulation of α-secretase. The gene was sequenced in 103 AD cases (82% familial) and 96 cognitively preserved nonagenarians.

De Novo PS1 Mutation (Pro436Gln) in a Very Early-Onset Posterior Variant of Alzheimer's Disease Associated with Spasticity: A Case Report.

We report a patient with sporadic Alzheimer's disease with onset in his twenties found to carry the de novo Pro436Gln mutation in the presenilin 1 gene (PS1). Clinical phenotype featured a posterior cortical syndrome with severe visual agnosia and mild limb spasticity with brisk reflexes. Brain MRI and FDG-PET scans revealed severe parieto-occipital atrophy/hypometabolism.

α-Secretase nonsense mutation (ADAM10 Tyr167*) in familial Alzheimer's disease.

Background: The disintegrin metalloproteinase 10 (ADAM10) is the main α-secretase acting in the non-amyloidogenic processing of APP. Some ADAM10 gene variants have been associated with higher susceptibility to develop late-onset AD, though clear clinical-genetic correlates remain elusive.

Methods: Clinical-genetic and biomarker study of a first family with early- and late-onset AD associated with a nonsense ADAM10 mutation (p.

Presence of tau astrogliopathy in frontotemporal dementia caused by a novel Grn nonsense (Trp2*) mutation.

Frontotemporal lobar degeneration caused by GRN mutations is mainly associated with a TDP-43 type A proteinopathy. We present a family with autosomal dominant frontotemporal lobar degeneration caused by a novel GRN nonsense mutation (c.5G>A: p.

Diversity of Cognitive Phenotypes Associated with C9ORF72 Hexanucleotide Expansion.

For diagnostic purposes, we screened for the C9ORF72 mutation in a) 162 FTLD cases, and b) 145 cases with other diagnoses but with some frontotemporal features or manifestations previously reported in C9 carriers. Ten cases (onset 50 to 75 years) harbored the expansion: seven had FTLD syndromes (4.3% of total, 11% of familial cases), and three (2%) had a different diagnosis.

C9ORF72 hexanucleotide expansions of 20-22 repeats are associated with frontotemporal deterioration.

Objective: Expansions of more than 30 hexanucleotide repetitions in the C9ORF72 gene are a common cause of frontotemporal dementia (FTD) or amyotrophic lateral sclerosis (ALS). However, the range of 20-30 repetitions is rarely found and still has unclear significance. A screening of our cohort of cases with FTD (n = 109) revealed 4 mutation carriers (>30 repetitions) but also 5 probands with 20-22 confirmed repetitions.

Cerebrospinal fluid markers in dementia with lewy bodies compared with Alzheimer disease.

Background: Most patients with dementia with Lewy bodies (DLB) exhibit diffuse plaque-only pathology with rare neocortical neurofibrillary tangles (NFTs), as opposed to the widespread cortical neurofibrillary-tau involvement in Alzheimer disease (AD). Another pathological difference is the astrocytic and microglial inflammatory responses, including release of interleukins (ILs), around the neuritic plaques and NFTs in AD brains that are absent or much lower in DLB. We analyzed cerebrospinal fluid (CSF) markers that reflect the pathological differences between AD and DLB.