Young-onset Alzheimer Research Articles

Prevalence of Neuropsychiatric Symptoms in Young-Onset Compared to Late-Onset Alzheimer’s Disease – Part 1: Findings of the Two-Year Longitudinal NeedYD-Study

Background/Aims: Knowledge about neuropsychiatric symptoms in young-onset Alzheimer’s disease (YO-AD) is scarce, but essential to establish a prognosis and plan care for YO-AD patients. The aim of this study is to assess frequency parameters of neuropsychiatric symptoms in YO-AD over 2 years and investigate whether there are differences compared with late-onset Alzheimer’s disease (LO-AD). Methods: 98 YO-AD and 123 LO-AD patients and caregivers from two prospective cohort studies were included and assessed every 6 months for 2 years, using the Neuropsychiatric Inventory to evaluate neuropsychiatric symptoms. Results: Over the course of 2 years, the incidence, prevalence and persistence of neuropsychiatric symptoms were in general lower in YO-AD than in LO-AD, specifically for delusions, agitation, depression, anxiety, apathy, irritability and aberrant motor behavior. Frequency of individual symptoms showed large variability in both groups. Within the group of YO-AD patients, apathy was the most prevalent symptom. Conclusion: Neuropsychiatric symptoms, notably apathy, should be paid appropriate attention to in the diagnosis and treatment of YO-AD patients. Further research is needed to gain insight into the mechanisms underlying the differences in neuropsychiatric symptoms between YO-AD and LO-AD.

Genetic testing in familial and young-onset Alzheimer's disease: mutation spectrum in a Serbian cohort

Alzheimer's disease (AD) is the most common form of dementia. To date, more than 200 mutations in three genes have been identified as cause of early-onset autosomal dominant inherited AD. The aim of this study was to characterize the mutation spectrum and describe genotype-phenotype correlations in Serbian patients with positive family history of AD or/and early-onset AD. We performed a genetic screening for mutations in the coding regions of Presenilins 1 and 2 (PSEN1 and PSEN2), as well as exons 16 and 17 of the Amyloid Precursor Protein gene (APP) in a total of 47 patients from Serbia with a clinical diagnosis of familial and/or early-onset AD (mean age at onset of 60.3 years; range 32–77). We found one novel mutation in PSEN1, one novel variant in PSEN2, and three previously described variants, one in each of the analyzed genes. Interestingly, we identified one patient harboring two heterozygous mutations: one in APP (p.L723P) and one in PSEN1 (p.R108Q).

A genome-wide study reveals rare CNVs exclusive to extreme phenotypes of Alzheimer disease

Studying rare extreme forms of Alzheimer disease (AD) may prove to be a useful strategy in identifying new genes involved in monogenic determinism of AD. Amyloid precursor protein (APP), PSEN1, and PSEN2 mutations account for only 85% of autosomal dominant early-onset AD (ADEOAD) families. We hypothesised that rare copy number variants (CNVs) could be involved in ADEOAD families without mutations in known genes, as well as in rare sporadic young-onset AD cases. Using high-resolution array comparative genomic hybridisation, we assessed the presence of rare CNVs in 21 unrelated ADEOAD cases, having no alteration on known genes, and 12 sporadic AD cases, with an age of onset younger than 55 years. The analysis revealed the presence of 7 singleton CNVs (4 in ADEOAD and 3 in sporadic cases) absent in 1078 controls and 912 late-onset AD cases. Strikingly, 4 out of 7 rearrangements target genes (KLK6, SLC30A3, MEOX2, and FPR2) encoding proteins that are tightly related to amyloid-β peptide metabolism or signalling. Although these variants are individually rare and restricted to particular subgroups of patients, these findings support the causal role, in human pathology, of a set of genes coding for molecules suspected for a long time to modify Aβ metabolism or signalling, and for which animal or cellular models have already been developed.

Heading disorientation in young-onset Alzheimer's disease patients

Heading disorientation in young-onset Alzheimer's disease patients

Awareness, assessment and education: An early-stage program to support caregivers of individuals with younger-onset Alzheimer's disease

Awareness, assessment and education: An early-stage program to support caregivers of individuals with younger-onset Alzheimer's disease

Mosaicism for Trisomy 21 in a Patient With Young-Onset Dementia

To describe a case of young-onset Alzheimer disease (AD) due to mosaicism for trisomy 21. Case report of a single patient. Tertiary referral dementia clinic. A 55-year-old man with a mild degree of developmental delay but no previous diagnosis of Down syndrome and only minimal physical manifestations of Down syndrome presented with gradually progressive cognitive impairment consistent with probable AD. Fluorescent in situ hybridization analysis of interphase chromosomes revealed trisomy 21 in 10% of peripheral lymphocytes. As mosaicism for trisomy 21 can present with no or minimal manifestations of Down syndrome, it may be underdiagnosed as a cause of early-onset AD. Occult mosaicism for trisomy 21 may explain in part the previously described association between family history of Down syndrome and risk of AD. Screening for mosaicism with fluorescent in situ hybridization is indicated in selected patients with mild developmental delay and those with AD of young onset.

P-031: Medial orbitofrontal cortex hyperperfusion in young onset Alzheimer’s disease

P-031: Medial orbitofrontal cortex hyperperfusion in young onset Alzheimer’s disease

P36.4 Differences in EEG synchronisation likelihood measurements between young and old onset Alzheimer’s disease

P36.4 Differences in EEG synchronisation likelihood measurements between young and old onset Alzheimer’s disease

P2-099: Biopsy-proven young-onset Alzheimer’s disease with parkinsonism

P2-099: Biopsy-proven young-onset Alzheimer’s disease with parkinsonism

Performance on MMSE sub-items and education level in presenilin-1 mutation carriers without dementia

Spanish-language screening tests that are sensitive to the early cognitive changes of Alzheimer's disease (AD) are needed. Persons known to be at 50% risk for young-onset AD due to presenilin-1 (PSEN1) mutations provide the opportunity to assess which measures on the Mini-mental State Examination (MMSE) are most sensitive to these early changes. We performed genetic and Spanish-language cognitive testing on 50 Mexican persons without dementia at risk for inheriting PSEN1 mutations. We then compared the performance on sub-items of the MMSE between PSEN1 mutation carriers (MCs) and non-carriers (NCs) using t-tests and Fisher's exact tests. Exploratory multiple logistic regression analyses were also performed. Twenty-nine persons were MCs and 21 NCs. NCs tended to achieve higher levels of education (p = 0.039) than did MCs. MCs tended to perform more poorly when spelling "MUNDO" backwards and on Orientation, particularly regarding the date. In multiple regression analyses the ability of backwards spelling to predict PSEN1 mutation status was reduced when education was included as an independent variable. Subjects in the earliest stage of PSEN1-related AD showed deficits on orientation to date and in divided attention when spelling backwards. It is unclear if educational level should be considered an associated feature or a con-founding variable in this population although it should be taken into account when considering performance on the MMSE task of divided attention. The relative lack of deficits on delayed recall of three words probably represents the insensitivity of this measure in early AD. This study supports the utility of autosomal dominant AD as a model of the more common sporadic form of the disorder.