Comprehensive genetic screening of early-onset dementia patients in an Austrian cohort-suggesting new disease-contributing genes.

Early-onset dementia (EOD), with symptom onset before age 65, has a strong genetic burden. Due to genetic and clinical overlaps between different types of dementia, whole-exome sequencing (WES) has emerged as an appropriate screening method for diagnostic testing and novel gene-finding approaches. We performed WES and C9orf72 repeat testing in 60 well-defined Austrian EOD patients. Seven patients (12%) carried likely disease-causing variants in monogenic genes, PSEN1, MAPT, APP, and GRN. Five patients (8%) were APOE4 homozygote carriers. Definite and possible risk variants were detected in the genes TREM2, SORL1, ABCA7 and TBK1. In an explorative approach, we cross-checked rare gene variants in our cohort with a curated neurodegeneration candidate gene list and identified DCTN1, MAPK8IP3, LRRK2, VPS13C and BACE1 as promising candidate genes. Conclusively, 12 cases (20%) carried variants relevant to patient counseling, comparable to previously reported studies, and can thus be considered genetically resolved. Reduced penetrance, oligogenic inheritance and not yet identified high-risk genes might explain the high number of unresolved cases. To address this issue, we provide complete genetic and phenotypic information (uploaded to the European Genome-phenome Archive), enabling other researchers to cross-check variants. Thereby, we hope to increase the chance of independently finding the same gene/variant-hit in other well-defined EOD patient cohorts, thus confirming new genetic risk variants or variant combinations.

Demographics, Symptoms, Psychotropic Use, and Caregiver Distress in Patients With Early vs Late Onset Dementia.

BACKGROUND: Understanding experiences and challenges faced by persons living with Early-Onset Dementia (EOD) compared to individuals diagnosed with Late-Onset Dementia (LOD) is important for the development of targeted interventions. OBJECTIVE: Describe differences in sociodemographic, neuropsychiatric behavioral symptoms, caregiver characteristics, and psychotropic use. DESIGN, SETTING, PARTICIPANTS: Cross-sectional, retrospective study including 908 UCLA Alzheimer's Dementia Care Program participants (177 with EOD and 731 with LOD). MEASUREMENTS: Onset of dementia was determined using age at program enrollment, with EOD defined as age <65 years and LOD defined as age >80 years. Sociodemographic and clinical characteristics were measured once at enrollment. Behavioral symptoms were measured using the Neuropsychiatric Inventory Questionnaire (NPI-Q) severity score and caregiver distress was measured using the NPI-Q distress score. Medications included antipsychotic, antidepressant, benzodiazepines and other hypnotics, antiepileptics, and dementia medications. RESULTS: EOD compared to LOD participants were more likely men, college graduates, married, live alone, and have fewer comorbidities. EOD caregivers were more often spouses (56% vs 26%, p <0.01), whereas LOD caregivers were more often children (57% vs 10%, p <0.01). EOD was associated with lower odds of being above the median (worse) NPI-Q severity (adjusted odds ratio [aOR], 0.58; 95% CI 0.35-0.96) and NPI-Q distress scores (aOR, 0.53; 95% CI 0.31-0.88). Psychotropic use did not differ between groups though symptoms were greater for LOD compared to EOD. CONCLUSION: Persons with EOD compared to LOD had sociodemographic differences, less health conditions, and fewer neuropsychiatric symptoms. Future policies could prioritize counseling for EOD patients and families, along with programs to support spousal caregivers of persons with EOD.

Post-diagnostic support for persons with young-onset dementia - a retrospective analysis based on data from the Swedish dementia registry SveDem.

BACKGROUND: Approximately 3.9 million persons worldwide have young-onset dementia. Symptoms related to young-onset dementia present distinct challenges related to finances, employment, and family. To provide tailored support, it is important to gain knowledge about the formal support available for persons with young-onset dementia. Therefore, this paper aims to describe formal support for persons with young-onset dementia in Sweden and the factors influencing this support. METHODS: This retrospective study used data on persons under 65 years of age (n = 284) from The Swedish Registry for Cognitive/Dementia Disorders (SveDem) between 2021 and 2022. SveDem was established to monitor the quality of dementia care in Sweden. Characteristics of participants were obtained, including age, sex, dementia diagnosis, MMSE, medications, accommodation, and care setting. Descriptive statistics and logistic regression were used to test for associations between participant characteristics and post-diagnostic support. RESULTS: Information and educational support were usually offered to the person with young-onset dementia (90.1%) and their family (78.9%). Approximately half of the sample were offered contact with a dementia nurse (49.3%), counsellor (51.4%), or needs assessor (47.9%). A minority (28.5%) were offered cognitive aids. Six regression models were conducted based on participant characteristics to predict the likelihood that persons were offered support. Support was not predicted by age, sex, children at home, accommodation, or medications. Lower MMSE scores (p < .05) and home help (p < .05) were significantly associated with offer of a needs assessor. Living together was a significant predictor (p < .01) for information and educational support offered to the family. Care setting significantly predicted (p < .01) an offer of information and educational support for the person and family members, as well as contact with a counsellor. CONCLUSION: This study indicates potential formal support shortages for persons with young-onset dementia in some areas of dementia care. Despite equal support across most characteristics, disparities based on care setting highlight the importance of specialised dementia care. Pre-diagnostic support is minimal, indicating challenges for persons with young-onset dementia to access these services before diagnosis. While our study has identified areas in need of improvement, we recommend further research to understand the changing support needs of those with young-onset dementia.

Living with young-onset dementia in the family - a mixed method study.

Background: Studies on disease-related obstructions experienced in everyday life of younger people with dementia (YOD ≤ 65 years) and their families are encouraged.Aim: To explore how the family carers experience six predefined topics that influence the everyday life and needs of persons with YOD.Method: A quantitative and a qualitative study including family carers of persons with young-onset Alzheimer's dementia (AD) and frontotemporal dementia (FTD). Seventy-four informants responded to the Camberwell Assessment of Needs in the Elderly (CANE) and individual interviews were conducted with 13 informants.Results: Family carers of persons with YOD reported few unmet needs in the CANE assessment. Needs related to behavior and close relationships were reported significantly more frequent (p < 0.1) in persons with FTD than in persons with AD. From the qualitative data, six main themes were emphasized: daily activities turned upside down, involuntary loss of previous social network, losing close relationship, but maintaining a friendship with the spouse, unpredictable behavior adds burdens to a changing life, health and life risks, and economic insecurity for future life and caring costs.Conclusion: Whilst family carers quantitatively reported unmet needs, the individual interviews reported several major difficulties in everyday life.

Early-onset dementia and risk of hip fracture and major osteoporotic fractures.

INTRODUCTION: There is limited knowledge about early-onset dementia (EOD) on fracture risk. METHODS: Individuals ages 50 to 64 were identified from the National Database of Health Insurance Claims and Specific Health Checkups of Japan (2012 to 2019). The association between EOD and fractures and the association between cholinesterase inhibitors for EOD and fractures were evaluated using logistic regression analyses. RESULTS: We identified 13,614 EOD patients and 9,144,560 cognitively healthy individuals. The analysis revealed that EOD was associated with an increased risk of hip fractures (adjusted odds ratio, 95% confidence interval: 8.79, 7.37-10.48), vertebral fractures (1.73, 1.48-2.01), and major osteoporotic fractures (2.05, 1.83-2.30) over 3 years. The use of cholinesterase inhibitors was significantly associated with a reduction in hip fractures among EOD patients (0.28, 0.11-0.69). DISCUSSION: EOD patients have a higher risk of osteoporotic fractures than cognitively healthy individuals. The use of cholinesterase inhibitors may reduce the risk of hip fracture among EOD patients. HIGHLIGHTS: It is unknown whether early-onset dementia (EOD) increases the risk of fractures. We identified 13,614 individuals with EOD using a nationwide administrative database. Patients with EOD have a higher risk of hip, vertebral, and major osteoporotic fractures. The use of cholinesterase inhibitors may reduce hip fracture among patients with EOD.

Choriocapillaris reduction accurately discriminates against early-onset Alzheimer's disease.

INTRODUCTION: This study addresses the urgent need for non-invasive early-onset Alzheimer's disease (EOAD) prediction. Using optical coherence tomography angiography (OCTA), we present a choriocapillaris model sensitive to EOAD, correlating with serum biomarkers. METHODS: Eighty-four EOAD patients and 73 controls were assigned to swept-source OCTA (SS-OCTA) or the spectral domain OCTA (SD-OCTA) cohorts. Our hypothesis on choriocapillaris predictive potential in EOAD was tested and validated in these two cohorts. RESULTS: Both cohorts revealed diminished choriocapillaris signals, demonstrating the highest discriminatory capability (area under the receiver operating characteristic curve: SS-OCTA 0.913, SD-OCTA 0.991; P < 0.001). A sparser SS-OCTA choriocapillaris correlated with increased serum amyloid beta (Aß)42, Aß42/40, and phosphorylated tau (p-tau)181 levels (all P < 0.05). Apolipoprotein E status did not affect choriocapillaris measurement. DISCUSSION: The choriocapillaris, observed in both cohorts, proves sensitive to EOAD diagnosis, and correlates with serum Aß and p-tau181 levels, suggesting its potential as a diagnostic tool for identifying and tracking microvascular changes in EOAD. HIGHLIGHTS: Optical coherence tomography angiography may be applied for non-invasive screening of Alzheimer's disease (AD). Choriocapillaris demonstrates high sensitivity and specificity for early-onset AD diagnosis. Microvascular dynamics abnormalities are associated with AD.

Associations of inner retinal layers with risk of incident dementia: An individual participant data analysis of four prospective cohort studies.

INTRODUCTION: Our main objective was to investigate whether retinal neurodegeneration, estimated from lower thickness of inner retinal layers, was associated with incident all-cause dementia and Alzheimer's disease (AD). METHODS: We performed an individual participant data meta-analysis using unpublished data from four prospective cohort studies with a total of 69,955 participants (n = 1087 cases of incident all-cause dementia; n = 520 cases incident AD; follow-up time median [interquartile range] 11.3 [8.8-11.5] years). RESULTS: General baseline characteristics of the study population were mean (standard deviation) age, 58.1 (8.8) years; 47% women. After adjustment, lower baseline macular retinal nerve fiber layer thickness was significantly associated with a 10% and 11% higher incidence of all-cause dementia and AD, respectively. Lower baseline macular ganglion cell-inner plexiform layer thickness was not significantly associated with these outcomes. DISCUSSION: These findings suggest that retinal neurodegeneration precedes the onset of clinical dementia. Retinal imaging tools may be informative biomarkers for the study of the early pathophysiology of dementia.

Brain Sagging Dementia.

PURPOSE OF REVIEW: Brain sagging dementia (BSD) is a rare but devastating form of early-onset dementia characterized by intracranial hypotension and behavioral changes resembling behavioral variant frontotemporal dementia. This review aims to provide a comprehensive overview of BSD, highlighting its pathomechanism, diagnostic tools, and available treatment options. RECENT FINDINGS: BSD exhibits a complex clinical manifestation with insidious onset and gradual progression of behavioral disinhibition, apathy, inertia, and speech alterations. Additionally, patients may exhibit brainstem and cerebellar signs such as hypersomnolence and gait disturbance. Although headaches are common, they may not always demonstrate typical orthostatic features. Recent radiological advances have improved the detection of CSF leaks, enabling targeted treatment and favorable outcomes. Understanding the pathomechanism and available diagnostic tools for BSD is crucial for a systematic approach to timely diagnosis and treatment of this reversible form of early-onset dementia, as patients often endure a complex and lengthy clinical course.

Survival in Huntington's disease and other young-onset dementias.

OBJECTIVES: To compare survival and risk factors associated with mortality in common young-onset dementias (YOD) including Huntington's disease. METHODS: This retrospective cohort study included inpatients from an Australian specialist neuropsychiatry service, over 20 years. Dementia diagnoses were based on consensus criteria and Huntington's disease (HD) was confirmed genetically. Mortality and cause of death were determined using linkage to the Australian Institute of Health and Welfare National Death Index. RESULTS: There were 386 individuals with YOD included. The dementia types included frontotemporal dementia (FTD) (24.5%), HD (21.2%) and Alzheimer's disease (AD) (20.5%). 63% (n = 243) individuals had died. The longest median survival was for those who had HD, 18.8 years from symptom onset and with a reduced mortality risk compared to AD and FTD (hazard ratio 0.5). Overall, people with YOD had significantly increased mortality, of 5-8 times, compared to the general population. Females with a YOD had higher standardised mortality ratio compared to males (9.3 vs. 4.9) overall. The most frequent cause of death in those with HD was reported as HD, with other causes of death in the other YOD-subtypes related to dementia and mental/behavioural disorders. DISCUSSION: This is the first Australian study to investigate survival and risk factors of mortality in people with YOD. YOD has a significant risk of death compared to the general population. Our findings provide useful clinical information for people affected by YOD as well as future planning and service provision.

Clinical characteristics of early-onset versus late-onset Alzheimer's disease: a systematic review and meta-analysis.

OBJECTIVES: A number of studies have compared Alzheimer's disease (AD), the commonest form of dementia, based on their age of onset, i.e. before the age of 65 years (early-onset AD, EO-AD) to those developing after 65 years of age (late-onset AD, LO-AD), but the differences are not clear. We performed a systematic review and meta-analysis to compare clinical characteristics between EO-AD and LO-AD. DESIGN, MEASUREMENTS, AND PARTICIPANTS: Medline, Embase, PsycINFO, and CINAHL databases were systematically searched for studies comparing time to diagnosis, cognitive scores, annual cognitive decline, activities of daily living (ADLs), neuropsychiatric symptoms (NPS), quality of life (QoL), and survival time for EO-AD and LO-AD patients. RESULTS: Forty-two studies were included (EO-AD participants n = 5,544; LO-AD participants n = 16,042). An inverse variance method with random effects models was used to calculate overall effect estimates for each outcome. People with EO-AD had significantly poorer baseline cognitive performance and faster cognitive decline but longer survival times than people with LO-AD. There was no evidence that EO-AD patients differ from people with LO-AD in terms of symptom onset to diagnosis time, ADLs, and NPS. There were insufficient data to estimate overall effects of differences in QoL in EO-AD compared to LO-AD. CONCLUSIONS: Our findings suggest that EO-AD differs from LO-AD in baseline cognition, cognitive decline, and survival time but otherwise has similar clinical characteristics to LO-AD. Larger studies using standardized questionnaires focusing on the clinical presentations are needed to better understand the impact of age of onset in AD.

A thematic analysis of psychotic symptoms in young-onset dementia.

OBJECTIVES: Exploration of the themes and content of psychotic symptoms in young-onset dementia (YOD) is limited to case analysis. The primary objective of this study was to determine the themes of psychotic symptoms in individuals diagnosed with YOD. DESIGN: Comprehensive retrospective file review of discharge summaries. SETTING: Neuropsychiatry, a specialist mental health service located at the Royal Melbourne Hospital, Australia. PARTICIPANTS: Inpatients at Neuropsychiatry admitted between 2018 and 2020 (inclusive). MEASUREMENTS: Data extracted included descriptions and prevalence of psychotic symptoms as well as general demographic and clinical data. Data analysis was conducted using a thematic approach. RESULTS: Twenty-three inpatients had a diagnosis of YOD with psychotic symptoms. Themes were identified in the domains of delusions (six themes), auditory hallucinations (five themes), and visual hallucinations (two themes). Strong recurring themes across the modalities of hallucinations and delusions were beliefs and experiences relating to paranoia, suspicion, harm, and abuse. Themes did not clearly intersect across the modalities of hallucinations and delusions. A degree of thematic heterogeneity existed within individuals, and individuals experienced delusions or hallucinations of multiple themes. The themes of the psychotic symptoms did not clearly relate to diagnostic category, nor to time from diagnosis. CONCLUSION: This study is the first thematic analysis of psychotic symptoms in YOD and provides further understanding of patient phenomenology and experiences of psychosis in YOD.

A systematic review of the prevalence of depression, anxiety, and apathy in frontotemporal dementia, atypical and young-onset Alzheimer's disease, and inherited dementia.

OBJECTIVES: Depression, anxiety, and apathy are the most commonly reported neuropsychiatric symptoms (NPS) in Alzheimer's disease (AD). Understanding their prevalence in rarer dementias such as frontotemporal dementia (FTD), primary progressive aphasia (PPA), posterior cortical atrophy (PCA), young-onset AD (YOAD), and inherited dementias has implications for both clinical practice and research. In this study, we aimed to examine the current state of knowledge of the prevalence of these three NPS in less prevalent dementias. DESIGN: We conducted a systematic review based on searches of EMBASE, PsycINFO, and PubMed up to September 2019. RESULTS: 47 articles meeting inclusion criteria were identified. Depression, anxiety, and apathy were commonly reported across the phenotypes studied but their prevalence showed large variation between studies. Apathy showed the highest reported frequency in FTD (50-100% across studies), behavioral variant frontotemporal dementia (bvFTD) (73-100%), and YOAD (44-100%). Anxiety was frequently reported in FTD (0-100%) and bvFTD (19-63%). Depression showed the highest prevalence in FTD (7-69%) and YOAD (11-55%). Among the three variants of PPA, sv-PPA is the one most investigated (seven articles). Three or fewer articles were identified examining NPS in the remaining PPA variants, PCA, familial AD, and familial FTD. Inconsistency in the tools used to measure symptoms and small sample sizes were common methodological limitations. CONCLUSIONS: Future studies should consider the inclusion of larger sample sizes (e.g. through multicenter collaborations) and the use of harmonized protocols that include the combination of caregiver and patient-derived measures and symptom-specific questionnaires. More research is needed on the phenotype-specific barriers and facilitators for people living with dementia to successfully engage in self-reports of NPS.

Establishing and sustaining high-quality services for people with young onset dementia: the perspective of senior service providers and commissioners.

OBJECTIVES: We aimed to understand the facilitators to developing and sustaining high-quality services for people with young onset dementia (YOD) and their families/supporters. DESIGN: This qualitative study used semi-structured interviews with commissioners and service managers, analyzed using inductive thematic analysis. SETTING: A purposive sample of providers was selected from diverse areas and contrasting YOD services. PARTICIPANTS: Eighteen senior staff from YOD services and two dementia service commissioners took part. MEASUREMENTS: For commissioners, key interview topics were experiences of commissioning YOD services, perceived facilitators or barriers, and how future guidance should be structured for ease of use. For service providers, key topics explored experiences of delivering YOD services; what was achievable or challenging; how the service was funded; how it linked with broader provision for YOD in the area; and how guidance should be structured. RESULTS: Recorded interviews lasted 30-40 minutes. Seven key facilitators to the development and sustaining of YOD services were identified: having knowledgeable, committed local champions; involvement of people living with YOD and family supporters; initial delivery within existing resources; partnership working within and between sectors; having a reflective, supportive organizational culture; gathering evidence of impact; and having wider support and guidance. CONCLUSIONS: Improvements in provision for those with YOD and their families need to be built on understanding of service-level and interpersonal influences as well as on understanding of YOD itself. Our findings highlight a set of facilitators which need to be in place to establish and sustain high-quality YOD services that fit the local context.

Developments in understanding early onset Alzheimer's disease.

On September 25 and 26, 2021, the Alzheimer's Association hosted the first meeting focused on people with early-onset Alzheimer's disease (EOAD)-sometimes referred to as younger onset Alzheimer's disease (AD). Though a diagnosis of AD can be devastating at any age, those with a younger onset-defined as symptoms developing prior to 65 years of age-face unique challenges. EOAD occurs when people are in the prime of their lives, often with multiple responsibilities including careers, community activities, and raising children and caring for older family members. These challenges warrant special consideration and study, yet people with EOAD are often excluded from AD research because of their atypical age of onset. To help fill this gap, we designed and launched the Longitudinal Early-Onset Alzheimer's Disease Study (LEADS) to enroll and follow 500 people with EOAD from > 15 sites in the United States, which the National Institute on Aging funded in 2018. The September 2021 meeting was designed to inform people with EOAD and their family members and caregivers about the latest research on the biology of EOAD, treatments in the pipeline, practical considerations about legal and financial arrangements for families, and the support networks available to them. More than 217 registrants attended.

Baseline neuropsychiatric symptoms and psychotropic medication use midway through data collection of the Longitudinal Early-Onset Alzheimer's Disease Study (LEADS) cohort.

INTRODUCTION: We examined neuropsychiatric symptoms (NPS) and psychotropic medication use in a large sample of individuals with early-onset Alzheimer's disease (EOAD; onset 40-64 years) at the midway point of data collection for the Longitudinal Early-onset Alzheimer's Disease Study (LEADS). METHODS: Baseline NPS (Neuropsychiatric Inventory - Questionnaire; Geriatric Depression Scale) and psychotropic medication use from 282 participants enrolled in LEADS were compared across diagnostic groups - amyloid-positive EOAD (n = 212) and amyloid negative early-onset non-Alzheimer's disease (EOnonAD; n = 70). RESULTS: Affective behaviors were the most common NPS in EOAD at similar frequencies to EOnonAD. Tension and impulse control behaviors were more common in EOnonAD. A minority of participants were using psychotropic medications, and use was higher in EOnonAD. DISCUSSION: Overall NPS burden and psychotropic medication use were higher in EOnonAD than EOAD participants. Future research will investigate moderators and etiological drivers of NPS, and NPS differences in EOAD versus late-onset AD.

Concussion and Chronic Traumatic Encephalopathy Deaths: Coroners' Inquests as a Catalyst for Public Health Reforms.

Deaths of participants in sport from the effects of concussive injuries and from chronic traumatic encephalopathy (CTE) raise confronting social issues and challenges for tort law. An uncertainty that often needs to be addressed in such cases is proof of the causes of the former athlete's symptomatology, especially when they may be multifactorial, some or all of which were not directly related to sport. Accounts from the person prior to their death and from family members can be vital sources of such information. Coroners' analyses of evidence in concussion-related deaths constitute an important opportunity for perspectives which can form a sound empirical basis for changes to sporting practices, rules and administration. This editorial reviews a series of biographical and autobiographical accounts of sportspersons with concussion and CTE. It also identifies a corpus of coronial decisions from England, New Zealand, Canada and Australia which have addressed the risks posed to athletes from concussive injuries. It highlights recommendations made by coroners in relation to management of concussion in sport and argues that there is considerable scope for further valuable recommendations based upon their investigations during inquests.

Initial symptoms of early-onset dementia in Japan: nationwide survey.

AIM: The aim of this study was to investigate initial symptoms of early-onset dementia (EOD) for each dementia subtype. METHOD: We conducted a nationwide, population-based EOD prevalence study in Japan. Data were collected through service providers for people with EOD. Initial symptoms were assessed in six domains: loss of memory, difficulty in word generation, irritability, loss of motivation, increased mistakes in the workplace or domestically, and unusual behaviours or attitudes other than those listed. RESULTS: Participants were 770 people with EOD. Characteristic initial symptoms were observed for each EOD subtype. Loss of memory was more common in early-onset Alzheimer's disease (75.7%, P < 0.001), difficulty in word generation was more common in early-onset vascular dementia (41.3%, P < 0.001), and loss of motivation, increased mistakes in the workplace or domestically, and unusual behaviours or attitudes other than those listed were more common in early-onset frontotemporal dementia (34.9%, P < 0.001; 49.4%, P < 0.001; 34.9%, P < 0.001, respectively). In addition, we observed gender differences whereby loss of memory was more common among women and irritability was more common among men. More than half of the participants were employed at symptom onset, and 57.2% of those who were employed at the onset had initial symptoms of increased mistakes in the workplace or domestically. CONCLUSION: This report reveals differences in the frequency of initial symptoms by EOD subtype. The results contribute to increasing public awareness of the initial symptoms of EOD, which will facilitate early diagnosis and social support.

C9orf72 repeat length might influence clinical sub-phenotypes in dementia patients.

BACKGROUND: C9orf72 repeat expansions have been observed in a wide variety of neurodegenerative disorders. The cut-off between normal and pathogenic alleles is not well established as repeat sizing methods are often semi-quantitative. However, intermediate alleles might influence disease prevalence and phenotype, as seen for other repeat expansion disorders. We aimed to further delineate the prevalence of small, intermediate and expanded C9orf72 alleles and elucidate their potential influence on the disease phenotype. METHODS: DNA derived from patients (n = 1804) and healthy individuals (n = 643) was obtained from multiple collectives in Austria. Genotyping was performed using a two-step PCR assay followed by Southern blotting. RESULTS: 3.4% of clinically diagnosed frontotemporal dementia (FTD; n = 5/147) cases and 0.8% of clinically diagnosed Alzheimer's disease (AD; n = 5/602) cases were carriers of a pathological C9orf72 repeat expansion. A significantly earlier disease onset was detected in expansion carriers compared to non-carriers in the FTD and AD cohorts (median 50 years, range 39-64 vs. median 64 years, range 36-92, p = 0.018 and median 63 years, range 54-71 vs. median 74 years, range 45-92, p = 0.006, respectively). C9orf72 intermediate alleles were significantly associated with cerebellar symptoms (p = 0.0004) and sensory deficits in the dementia cohort (p = 0.01). CONCLUSIONS: C9orf72 repeat expansion carriers showed earlier disease onset compared to non-carriers with clinical diagnosis of FTD and AD. Furthermore, C9orf72 intermediate repeats might modify the phenotypic expression in dementia.

Clinical impact of whole-genome sequencing in patients with early-onset dementia.

BACKGROUND: In the clinical setting, identification of the genetic cause in patients with early-onset dementia (EOD) is challenging due to multiple types of genetic tests required to arrive at a diagnosis. Whole-genome sequencing (WGS) has the potential to serve as a single diagnostic platform, due to its superior ability to detect common, rare and structural genetic variation. METHODS: WGS analysis was performed in 50 patients with EOD. Point mutations, small insertions/deletions, as well as structural variants (SVs) and short tandem repeats (STRs), were analysed. An Alzheimer's disease (AD)-related polygenic risk score (PRS) was calculated in patients with AD. RESULTS: Clinical genetic diagnosis was achieved in 7 of 50 (14%) of the patients, with a further 8 patients (16%) found to have established risk factors which may have contributed to their EOD. Two pathogenic variants were identified through SV analysis. No expanded STRs were found in this study cohort, but a blinded analysis with a positive control identified a C9orf72 expansion accurately. Approximately 37% (7 of 19) of patients with AD had a PRS equivalent to >90th percentile risk. DISCUSSION: WGS acts as a single genetic test to identify different types of clinically relevant genetic variations in patients with EOD. WGS, if used as a first-line clinical diagnostic test, has the potential to increase the diagnostic yield and reduce time to diagnosis for EOD.

Carer burden and psychological distress in young-onset dementia: An Australian perspective.

OBJECTIVES: Carer burden in dementia is associated with poor outcomes, including early nursing home placement for people with dementia and psychological distress for their carers. Carers of people with young-onset dementia (YOD) are particularly vulnerable to carer burden. Yet they are often overlooked by clinicians as dementia services are generally designed for older people. We sought to estimate the rate of burden and psychological distress in carers of YOD at a state-wide tertiary service based in Australia. METHODS: We conducted a cross-sectional study examining 71 dyads from a Neuropsychiatry service. We collected patient demographic and clinical data including the Neuropsychiatry Unit Cognitive Assessment tool (NUCOG) and Mini-Mental State Examination (MMSE). Carer data, such as demographics and psychological distress, were obtained using Depression Anxiety Stress Scale 21 (DASS-21). Carer burden was rated using the Zarit Burden Inventory-short version (ZBI). RESULTS: Higher carer burden, measured using ZBI, was associated with longer duration of dementia and greater severity of overall cognitive impairment. Carers who felt burdened reported higher levels of stress, depression, and anxiety measured using DASS-21. Multiple linear regression analysis found carer burden was independently predicted by duration of dementia, total cognition score and carers experiencing psychological stress. DISCUSSION: We found that patient variables of dementia duration and cognitive impairment and carer variable of carer stress to be associated with carer burden. Poor executive function was associated with carer stress. Early identification and management of carer burden and psychological distress is important for outcomes. Ideally, this should be provided by a specialist YOD service.