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1.
Article in English | MEDLINE | ID: mdl-36204161

ABSTRACT

Introduction: Observable dementia symptoms are hardly studied in people with severe/profound intellectual (and multiple) disabilities (SPI(M)D). Insight in symptomatology is needed for timely signaling/diagnosis. This study aimed to identify practice-based observations of dementia symptoms in this population. Methods: Care professionals and family members were invited to complete a survey about symptoms. Quantitatively analyzed survey data were further deepened through semi-structured interviews with care professionals having vast experience in signaling/diagnosing dementia in this population. Symptoms were categorized using a symptom matrix. Results: Survey respondents and interviewees frequently observed a decline in activities of daily living (ADL) functioning and behavioral and psychological changes, like increased irritability, anxiety, apathy and decreased eating/drinking behavior. Cognitive symptoms were particularly recognized in persons with verbal communication and/or walking skills. To lesser extent motor changes and medical comorbidities were reported. Conclusion: Increased insight in dementia symptoms contributes to developing a dedicated screening instrument for dementia in people with SPI(M)D.

2.
Res Dev Disabil ; 129: 104302, 2022 Oct.
Article in English | MEDLINE | ID: mdl-35853354

ABSTRACT

BACKGROUND: In daily practice, sleep apnea is underdiagnosed in people with Down syndrome. The WatchPAT can detect sleep apnea in a less invasive way. AIM: This study aimed to evaluate the feasibility of the WatchPAT to detect sleep apnea in individuals with Down syndrome. METHODS AND PROCEDURES: Thirty-one participants with Down syndrome (aged 18+) were included. Sleep apnea was detected with the WatchPAT and compared to results of the STOP-Bang Questionnaire (current practice). Experiences of participants, caregivers and clinicians were studied using a combination of quantitative and qualitative methods. OUTCOMES AND RESULTS: Among the 68% of participants who accepted the WatchPAT, sleep apnea was detected in 95% of participants. Younger participants and participants with mild/moderate intellectual disabilities were more likely to accept the device. STOP-Bang did not detect most cases of sleep apnea. For the degree of sleep apnea, interrater reliability was substantial (k = 0.71) to almost perfect (k = 0.91). Considering experiences, caregivers and clinicians were predominantly positive about the WatchPAT. CONCLUSIONS: Our study showed that the WatchPAT is a promising device to detect sleep apnea in people with Down syndrome. Compared to polysomnography, detection with this device is less invasive and less burdensome for people with Down syndrome. Furthermore, the WatchPAT is a relatively accessible solution to implement in care institutions.


Subject(s)
Down Syndrome , Sleep Apnea Syndromes , Sleep Apnea, Obstructive , Adult , Feasibility Studies , Humans , Reproducibility of Results , Sleep Apnea Syndromes/diagnosis , Sleep Apnea, Obstructive/diagnosis , Sleep Apnea, Obstructive/epidemiology , Surveys and Questionnaires
3.
J Appl Res Intellect Disabil ; 35(1): 24-45, 2022 Jan.
Article in English | MEDLINE | ID: mdl-34219327

ABSTRACT

BACKGROUND: Dementia is increasingly prevalent in people with severe/profound intellectual disabilities. However, early detection and diagnosis of dementia is complex in this population. This study aimed to identify observable dementia symptoms in adults with severe/profound intellectual disabilities in available literature. METHOD: A systematic literature search was conducted in PubMed, PsycINFO and Web of Science with an exhaustive search string using a combination of search terms for severe/profound intellectual disabilities and dementia/ageing. RESULTS: Eleven studies met inclusion criteria. Cognitive decline, behavioural and psychological alterations, decline in activities of daily living as well as neurological and physical changes were found. CONCLUSIONS: Only a very limited number of studies reported symptoms ascribed to dementia in adults with severe/profound intellectual disabilities. Given the complexity of signalling and diagnosing dementia, dedicated studies are required to unravel the natural history of dementia in this population.


Subject(s)
Dementia , Intellectual Disability , Activities of Daily Living , Humans , Intellectual Disability/diagnosis , Intellectual Disability/epidemiology
4.
Mol Syndromol ; 12(4): 202-218, 2021 Jul.
Article in English | MEDLINE | ID: mdl-34421499

ABSTRACT

Research focused on Down syndrome has increased in the last several years to advance understanding of the consequences of trisomy 21 (T21) on molecular and cellular processes and, ultimately, on individuals with Down syndrome. The Trisomy 21 Research Society (T21RS) is the premier scientific organization for researchers and clinicians studying Down syndrome. The Third International Conference of T21RS, held June 6-9, 2019, in Barcelona, Spain, brought together 429 scientists, families, and industry representatives to share the latest discoveries on underlying cellular and molecular mechanisms of T21, define cognitive and behavioral challenges and better understand comorbidities associated with Down syndrome, including Alzheimer's disease and leukemia. Presentation of cutting-edge results in neuroscience, neurology, model systems, psychology, cancer, biomarkers and molecular and phar-ma-cological therapeutic approaches demonstrate the compelling interest and continuing advancement in all aspects of understanding and ameliorating conditions associated with T21.

5.
J Appl Res Intellect Disabil ; 34(6): 1602-1617, 2021 Nov.
Article in English | MEDLINE | ID: mdl-34212466

ABSTRACT

BACKGROUND: Differentiating dementia from baseline level of functioning is difficult among people with severe/profound intellectual (and multiple) disabilities. Moreover, studies on observable dementia symptoms are scarce. This study examined (a) the relevance of dementia diagnosis, (b) observable symptoms and (c) training/information needs. METHODS: Four explorative focus groups were held with care professionals and family members who have experience with people with severe/profound intellectual (and multiple) disabilities (≥40 years) and decline/dementia. RESULTS: Thematic analysis showed that participants wanted to know about a dementia diagnosis for a better understanding and to be able to make informed choices (question 1). Using a categorisation matrix, cognitive and behavioural changes were shown to be most prominent (question 2). Participants indicated that they needed enhanced training, more knowledge development and translation, and supportive organisational choices/policies (question 3). CONCLUSIONS: Timely identifying/diagnosing dementia allows for a timely response to changing needs. This requires a better understanding of symptoms.


Subject(s)
Dementia , Disabled Persons , Intellectual Disability , Dementia/diagnosis , Family , Focus Groups , Humans , Intellectual Disability/diagnosis
7.
J Alzheimers Dis ; 81(4): 1505-1527, 2021.
Article in English | MEDLINE | ID: mdl-33967040

ABSTRACT

BACKGROUND: People with Down syndrome (DS) are at high risk to develop Alzheimer's disease dementia (AD). Behavioral and psychological symptoms of dementia (BPSD) are common and may also serve as early signals for dementia. However, comprehensive evaluation scales for BPSD, adapted to DS, are lacking. Therefore, we previously developed the BPSD-DS scale to identify behavioral changes between the last six months and pre-existing life-long characteristic behavior. OBJECTIVE: To optimize and further study the scale (discriminative ability and reliability) in a large representative DS study population. METHODS: Optimization was based on item irrelevance and clinical experiences obtained in the initial study. Using the shortened and refined BPSD-DS II, informant interviews were conducted to evaluate 524 individuals with DS grouped according to dementia status: no dementia (DS, N = 292), questionable dementia (DS + Q, N = 119), and clinically diagnosed dementia (DS + AD, N = 113). RESULTS: Comparing item change scores between groups revealed prominent changes in frequency and severity for anxious, sleep-related, irritable, restless/stereotypic, apathetic, depressive, and eating/drinking behavior. For most items, the proportion of individuals displaying an increased frequency was highest in DS + AD, intermediate in DS + Q, and lowest in DS. For various items within sections about anxious, sleep-related, irritable, apathetic, and depressive behaviors, the proportion of individuals showing an increased frequency was already substantial in DS + Q, suggesting that these changes may serve as early signals of AD in DS. Reliability data were promising. CONCLUSION: The optimized scale yields largely similar results as obtained with the initial version. Systematically evaluating BPSD in DS may increase understanding of changes among caregivers and (timely) adaptation of care/treatment.


Subject(s)
Dementia/diagnosis , Down Syndrome/complications , Adult , Aged , Anxiety/psychology , Dementia/complications , Dementia/psychology , Down Syndrome/psychology , Female , Humans , Irritable Mood/physiology , Male , Middle Aged , Reproducibility of Results , Symptom Assessment
8.
Mol Syndromol ; 9(6): 279-286, 2019 Jan.
Article in English | MEDLINE | ID: mdl-30800043

ABSTRACT

In the last decade, a number of important research advances in different fields have allowed Down syndrome (DS) research to flourish, creating a time of both unparalleled opportunity and considerable challenge. Building a scientific framework that distills mechanisms involved in the developmental intellectual disability of DS as well as the early-onset component of Alzheimer disease and the several other comorbidities associated with the condition is a challenge that scientists are now tackling using novel technologies and multidisciplinary approaches. The Trisomy 21 Research Society (T21RS) was founded in 2014 to address these evolving needs and challenges. In June of 2017, the T21RS held its 2nd International Conference in Chicago, USA. With more than 200 scientists, advocates, people with DS, and family members in attendance, the meeting served as a forum for the discussion of the latest research and clinical advances as well as the most compelling needs of people with DS and their families.

9.
Tijdschr Gerontol Geriatr ; 49(5): 187-205, 2018 Oct.
Article in Dutch | MEDLINE | ID: mdl-30238286

ABSTRACT

Behavioral and psychological symptoms of dementia (BPSD) have not been comprehensively studied in people with Down syndrome, despite their high risk on dementia. A novel evaluation scale was developed to identify the nature, frequency and severity of behavioral changes (83 behavioral items in 12 clinically defined sections). Central aim was to identify items that change in relation to the dementia status. Structured interviews were conducted with informants of people with Down syndrome without dementia (DS, N = 149), with questionable dementia (DS + TD, N = 65) and with diagnosed dementia (DS + AD, N = 67). Group comparisons showed a pronounced increase in frequency and severity of items about anxiety, sleep disturbances, agitation & stereotypical behavior, aggression, apathy, depressive symptoms, and, eating/drinking behavior. The proportion of individuals presenting an increase was highest in the DS + AD group and lowest in the DS group. Interestingly, among DS + TD individuals, a substantial proportion already presented increased anxiety, sleep disturbances, apathy and depressive symptoms, suggesting that these changes may be early alarm signals of dementia. The scale may contribute to a better understanding of the changes, adapting daily care/support, and providing suitable therapies to people with Down syndrome. The scale needs to be optimized based on the results and experiences. The applicability, reliability and validity require further study.


Subject(s)
Dementia/diagnosis , Down Syndrome/psychology , Problem Behavior/psychology , Aged , Anxiety/diagnosis , Anxiety/etiology , Apathy , Case-Control Studies , Depression/diagnosis , Depression/etiology , Diagnosis, Differential , Female , Humans , Male , Psychopathology
10.
Alzheimers Dement (Amst) ; 10: 99-111, 2018.
Article in English | MEDLINE | ID: mdl-29780859

ABSTRACT

INTRODUCTION: People with Down syndrome (DS) are at high risk for Alzheimer's disease (AD). Defects in monoamine neurotransmitter systems are implicated in DS and AD but have not been comprehensively studied in DS. METHODS: Noradrenaline, adrenaline, and their metabolite 3-methoxy-4-hydroxyphenylglycol (MHPG); dopamine and its metabolites 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid; and serotonin and its metabolite 5-hydroxyindoleacetic acid were quantified in 15 brain regions of DS without AD (DS, n = 4), DS with AD (DS+AD, n = 17), early-onset AD (EOAD, n = 11) patients, and healthy non-DS controls (n = 10) in the general population. Moreover, monoaminergic concentrations were determined in cerebrospinal fluid (CSF)/plasma samples of DS (n = 37/149), DS with prodromal AD (DS+pAD, n = 13/36), and DS+AD (n = 18/40). RESULTS: In brain, noradrenergic and serotonergic compounds were overall reduced in DS+AD versus EOAD, while the dopaminergic system showed a bidirectional change. For DS versus non-DS controls, significantly decreased MHPG levels were noted in various brain regions, though to a lesser extent than for DS+AD versus EOAD. Apart from DOPAC, CSF/plasma concentrations were not altered between groups. DISCUSSION: Monoamine neurotransmitters and metabolites were evidently impacted in DS, DS+AD, and EOAD. DS and DS+AD presented a remarkably similar monoaminergic profile, possibly related to early deposition of amyloid pathology in DS. To confirm whether monoaminergic alterations are indeed due to early amyloid ß accumulation, future avenues include positron emission tomography studies of monoaminergic neurotransmission in relation to amyloid deposition, as well as relating monoaminergic concentrations to CSF/plasma levels of amyloid ß and tau within individuals.

11.
J Alzheimers Dis ; 63(2): 797-819, 2018.
Article in English | MEDLINE | ID: mdl-29689719

ABSTRACT

People with Down syndrome (DS) are prone to develop Alzheimer's disease (AD). Behavioral and psychological symptoms of dementia (BPSD) are core features, but have not been comprehensively evaluated in DS. In a European multidisciplinary study, the novel Behavioral and Psychological Symptoms of Dementia in Down Syndrome (BPSD-DS) scale was developed to identify frequency and severity of behavioral changes taking account of life-long characteristic behavior. 83 behavioral items in 12 clinically defined sections were evaluated. The central aim was to identify items that change in relation to the dementia status, and thus may differentiate between diagnostic groups. Structured interviews were conducted with informants of persons with DS without dementia (DS, n = 149), with questionable dementia (DS+Q, n = 65), and with diagnosed dementia (DS+AD, n = 67). First exploratory data suggest promising interrater, test-retest, and internal consistency reliability measures. Concerning item relevance, group comparisons revealed pronounced increases in frequency and severity in items of anxiety, sleep disturbances, agitation & stereotypical behavior, aggression, apathy, depressive symptoms, and eating/drinking behavior. The proportion of individuals presenting an increase was highest in DS+AD, intermediate in DS+Q, and lowest in DS. Interestingly, among DS+Q individuals, a substantial proportion already presented increased anxiety, sleep disturbances, apathy, and depressive symptoms, suggesting that these changes occur early in the course of AD. Future efforts should optimize the scale based on current results and clinical experiences, and further study applicability, reliability, and validity. Future application of the scale in daily care may aid caregivers to understand changes, and contribute to timely interventions and adaptation of caregiving.


Subject(s)
Dementia/diagnosis , Down Syndrome/diagnosis , Adult , Aged , Behavioral Symptoms , Cross-Sectional Studies , Dementia/psychology , Down Syndrome/psychology , Female , Humans , Interviews as Topic , Male , Middle Aged , Neuropsychological Tests , Observer Variation , Reproducibility of Results , Severity of Illness Index
12.
Sci Rep ; 8(1): 2859, 2018 02 12.
Article in English | MEDLINE | ID: mdl-29434250

ABSTRACT

Inhibition of DYRK1A kinase, produced by chromosome 21 and consequently overproduced in trisomy 21 subjects, has been suggested as a therapeutic approach to treating the cognitive deficiencies observed in Down syndrome (DS). We now report the synthesis and potent DYRK1A inhibitory activities of fluoro derivatives of 3,5-di(polyhydroxyaryl)-7-azaindoles (F-DANDYs). One of these compounds (3-(4-fluorophenyl)-5-(3,4-dihydroxyphenyl)-1H-pyrrolo[2,3-b]pyridine, 5a) was selected for in vivo studies of cognitive rescuing effects in a standard mouse model of DS (Ts65Dn line). Using the Morris water maze task, Ts65Dn mice treated i.p. with 20 mg/kg of 5a performed significantly better than Ts65Dn mice treated with placebo, confirming the promnesiant effect of 5a in the trisomic mice. Overall, these results demonstrate for the first time that selective and competitive inhibition of DYRK1A kinase by the F-DANDY derivative 5a may provide a viable treatment strategy for combating the memory and learning deficiencies encountered in DS.


Subject(s)
Down Syndrome/psychology , Maze Learning/drug effects , Protein Serine-Threonine Kinases/antagonists & inhibitors , Protein-Tyrosine Kinases/antagonists & inhibitors , Pyridines/administration & dosage , Animals , Cognition/drug effects , Disease Models, Animal , Down Syndrome/enzymology , Humans , Injections, Intraperitoneal , Learning Disabilities/drug therapy , Memory Disorders/drug therapy , Mice , Molecular Structure , Protein Kinase Inhibitors/administration & dosage , Protein Kinase Inhibitors/chemistry , Protein Kinase Inhibitors/pharmacology , Pyridines/chemistry , Pyridines/pharmacology , Dyrk Kinases
13.
Neurobiol Dis ; 105: 235-244, 2017 Sep.
Article in English | MEDLINE | ID: mdl-28624415

ABSTRACT

Altered concentrations of monoamine neurotransmitters and metabolites have been repeatedly found in people with Down syndrome (DS, trisomy 21). Because of the limited availability of human post-mortem tissue, DS mouse models are of great interest to study these changes and the underlying neurobiological mechanisms. Although previous studies have shown the potential of Ts65Dn mice - the most widely used mouse model of DS - to model noradrenergic changes, a comprehensive monoaminergic characterization in multiple brain regions has not been performed so far. Here, we used RP-HPLC with electrochemical detection to quantify (nor)adrenergic (NA, adrenaline and MHPG), dopaminergic (DA, HVA and DOPAC), and serotonergic compounds (tryptophan, 5-HT and 5-HIAA) in ten regionally dissected brain regions of Ts65Dn mice, as well as in Dp1Tyb mice - a novel DS mouse model. Comparing young adult aneuploid mice (2.5-5.5months) with their euploid WT littermates did not reveal generalized monoaminergic dysregulation, indicating that the genetic overload in these mice barely affected the absolute concentrations at this age. Moreover, we studied the effect of aging in Ts65Dn mice: comparing aged animals (12-13months) with their younger counterparts revealed a large number of significant changes. In general, the (nor)adrenergic system appeared to be reduced, while serotonergic compounds were increased with aging. Dopaminergic alterations were less consistent. These overall patterns appeared to be relatively similar for Ts65Dn and WT mice, though more observed changes were regarded significant for WT mice. Similar human post-mortem studies are necessary to validate the monoaminergic construct validity of the Ts65Dn and Dp1Typ mouse models.


Subject(s)
Aging , Aneuploidy , Biogenic Monoamines/metabolism , Brain/metabolism , Down Syndrome/pathology , Animals , Chromatography, High Pressure Liquid , Disease Models, Animal , Down Syndrome/genetics , Electrochemical Techniques , Male , Mice , Mice, Inbred C57BL , Neurotransmitter Agents/metabolism , Statistics, Nonparametric
14.
Article in English | MEDLINE | ID: mdl-28413821

ABSTRACT

Down syndrome (DS), present in nearly six million people, is associated with an extremely high risk to develop Alzheimer's disease (AD). Amyloid-ß and tau pathology are omnipresent from age 40 years onward, but clinical symptoms do not appear in all DS individuals. Dementia diagnostics is complex in this population, illustrating the great need for predictive biomarkers. Although blood biomarkers have not yet proven useful, cerebrospinal fluid (CSF) biomarkers (low amyloid-ß42, high t-tau, and high p-tau) effectively contribute to AD diagnoses in the general population and are increasingly used in clinical practice. Surprisingly, CSF biomarkers have been barely evaluated in DS. Breaking the taboo on CSF analyses would finally allow for the elucidation of its utility in (differential) diagnoses and staging of disease severity. A sensitive and specific biomarker profile for AD in DS would be of paramount importance to daily care, adaptive caregiving, and specific therapeutic interventions.

15.
Curr Alzheimer Res ; 13(10): 1145-64, 2016.
Article in English | MEDLINE | ID: mdl-27137218

ABSTRACT

Neuropsychiatric symptoms (NPS) are an integral part of the dementia syndrome and were therefore recently included in the core diagnostic criteria of dementia. The near universal prevalence of NPS in Alzheimer's disease (AD), combined with their disabling effects on patients and caregivers, is contrasted by the fact that few effective and safe treatments exist, which is in part to be attributed to our incomplete understanding of the neurobiology of NPS. In this review, we describe the pathological alterations typical for AD, including spreading and evolution of burden, effect on the molecular and cellular integrity, functional consequences and atrophy of NPS-relevant brain regions and circuits in correlation with specific NPS assessments. It is thereby clearly established that NPS are fundamental expressions of the underlying neurodegenerative brain disease and not simply reflect the patients' secondary response to their illness. Neuropathological studies, moreover, include a majority of end-stage patient samples, which may not correctly represent the pathophysiological environment responsible for particular NPS that may already be present in an early stage, or even prior to AD diagnosis. The burdensome nature and high prevalence of NPS, in combination with the absence of effective and safe pharmacotherapies, provide a strong incentive to continue neuropathological and neurochemical, as well as imaging and other relevant approaches to further improve our apprehension of the neurobiology of NPS.


Subject(s)
Alzheimer Disease/complications , Alzheimer Disease/pathology , Behavioral Symptoms/etiology , Brain/pathology , Cognition Disorders/etiology , Behavioral Symptoms/pathology , Brain/metabolism , Caregivers/psychology , Cognition Disorders/pathology , Encephalitis/etiology , Humans
16.
Cortex ; 73: 36-61, 2015 Dec.
Article in English | MEDLINE | ID: mdl-26343344

ABSTRACT

Behavioural and Psychological Symptoms of Dementia (BPSD) are a core symptom of dementia and are associated with suffering, earlier institutionalization and accelerated cognitive decline for patients and increased caregiver burden. Despite the extremely high risk for Down syndrome (DS) individuals to develop dementia due to Alzheimer's disease (AD), BPSD have not been comprehensively assessed in the DS population. Due to the great variety of DS cohorts, diagnostic methodologies, sub-optimal scales, covariates and outcome measures, it is questionable whether BPSD have always been accurately assessed. However, accurate recognition of BPSD may increase awareness and understanding of these behavioural aberrations, thus enabling adaptive caregiving and, importantly, allowing for therapeutic interventions. Particular BPSD can be observed (long) before the clinical dementia diagnosis and could therefore serve as early indicators of those at risk, and provide a new, non-invasive way to monitor, or at least give an indication of, the complex progression to dementia in DS. Therefore, this review summarizes and evaluates the rather limited knowledge on BPSD in DS and highlights its importance and potential for daily clinical practice.


Subject(s)
Alzheimer Disease/diagnosis , Alzheimer Disease/psychology , Behavioral Symptoms/psychology , Cognition Disorders/psychology , Down Syndrome/psychology , Alzheimer Disease/complications , Animals , Disease Progression , Down Syndrome/complications , Down Syndrome/diagnosis , Humans , Neuropsychological Tests
17.
J Alzheimers Dis ; 45(3): 733-43, 2015.
Article in English | MEDLINE | ID: mdl-25613101

ABSTRACT

BACKGROUND: The majority of people with Down syndrome (DS) develop dementia due to Alzheimer's disease (AD). Neuropathological features are characterized by an accumulation of amyloid-ß (Aß) deposits and the presence of an activated immune response. Neutrophil Gelatinase-Associated Lipocalin (NGAL) is a newly identified (neuro)inflammatory constituent in AD. OBJECTIVE: This study examines NGAL as an inflammatory marker in DS and its associations with plasma Aß peptides according to the follow-up clinical diagnosis of dementia. METHODS: Baseline serum NGAL and plasma Aß40, Aß42, Aß(n40), and Aß(n42) were quantified in 204 people with DS. The diagnosis of dementia in DS was established by follow-up clinical assessments. The following study groups were characterized: DS with AD at baseline (n = 67), DS without AD (n = 53), and non-demented DS individuals that converted to AD (n = 84). Serum NGAL was analyzed in 55 elderly non-DS, non-demented people. RESULTS: Serum NGAL levels were significantly increased in DS subjects compared to non-DS people. Serum NGAL levels were not associated with clinical dementia symptoms in DS. However, NGAL was positively associated with Aß42 and Aß(n42) in demented DS individuals and with Aß40 and Aß(n40) in the non-demented DS group. NGAL was negatively associated with Aß42/Aß40 and Aß(n42)/Aß(n40) ratios in converted DS subjects. These associations persisted for Aß(n40), Aß42/Aß40, and Aß(n42)/Aß(n40) after adjusting for demographics measures, apolipoprotein E ε4 allele, platelets, and anti-inflammatory medication. CONCLUSION: Serum NGAL levels are increased in DS and associated with distinct species of Aß depending on the progression of dementia as diagnosed by baseline and follow-up clinical assessments.


Subject(s)
Amyloid beta-Peptides/blood , Dementia , Down Syndrome/complications , Lipocalins/blood , Proto-Oncogene Proteins/blood , Acute-Phase Proteins , Aged , Aged, 80 and over , Analysis of Variance , Dementia/blood , Dementia/diagnosis , Dementia/etiology , Female , Humans , Lipocalin-2 , Longitudinal Studies , Male , Middle Aged , Psychiatric Status Rating Scales
18.
J Alzheimers Dis ; 43(3): 871-91, 2015.
Article in English | MEDLINE | ID: mdl-25125467

ABSTRACT

BACKGROUND: Down syndrome (DS) is the most prevalent genetic cause of intellectual disability. Early-onset Alzheimer's disease (AD) frequently develops in DS and is characterized by progressive memory loss and behavioral and psychological signs and symptoms of dementia (BPSD). Predicting and monitoring the progression of AD in DS is necessary to enable adaptive caretaking. OBJECTIVE: Reliable blood biomarkers that aid the prediction of AD are necessary, since cerebrospinal fluid sampling is rather burdensome, particularly for people with DS. Here, we investigate serum levels of eight biogenic amines and their metabolites in relation to dementia staging and probable BPSD items. METHODS: Using RP-HPLC with electrochemical detection, (nor)adrenergic (NA/A and MHPG), serotonergic (5-HT and 5-HIAA), and dopaminergic (DA, HVA, and DOPAC) compounds were quantified in the serum of DS subjects with established AD at baseline (n = 51), DS subjects without AD (n = 50), non-demented DS individuals that converted to AD over time (n = 50), and, finally, healthy non-DS controls (n = 22). RESULTS: Serum MHPG levels were significantly lower in demented and converted DS subjects (p < 0.0001) compared to non-demented DS individuals and healthy controls. Those subjects with MHPG levels below median had a more than tenfold increased risk of developing dementia. Furthermore, significant correlations were observed between monoaminergic serum values and various probable BPSD items within each DS group. CONCLUSION: Decreased serum MHPG levels show great potential as biomarker to monitor and predict conversion to AD in DS. Moreover, significant monoaminergic alterations related to probable BPSD items, suggesting that monoaminergic dysregulation is an underlying biological mechanism, and demonstrating the need to develop a validated rating scale for BPSD in DS.


Subject(s)
Alzheimer Disease/diagnosis , Amyloid beta-Peptides/blood , Down Syndrome/blood , Methoxyhydroxyphenylglycol/blood , Peptide Fragments/blood , Alzheimer Disease/blood , Biomarkers/blood , Disease Progression , Dopamine/blood , Female , Humans , Male , Middle Aged , Norepinephrine/blood
19.
Neurosci Biobehav Rev ; 45: 72-84, 2014 Sep.
Article in English | MEDLINE | ID: mdl-24858130

ABSTRACT

Down syndrome (DS) is the most common genetic intellectual disability, caused by the triplication of the human chromosome 21 (HSA21). Although this would theoretically lead to a 1.5 fold increase in gene transcription, transcript levels of many genes significantly deviate. Surprisingly, the underlying cause of this gene expression variation has been largely neglected so far. Epigenetic mechanisms, including DNA methylation and post-translational histone modifications, regulate gene expression and as such might play a crucial role in the development of the cognitive deficits in DS. Various overexpressed HSA21 proteins affect epigenetic mechanisms and DS individuals are thus likely to present epigenetic aberrations. Importantly, epigenetic marks are reversible, offering a huge therapeutic potential to alleviate or cure certain genetic deficits. Current epigenetic therapies are already used for cancer and epilepsy, and might provide novel possibilities for cognition-enhancing treatment in DS as well. To that end, this review discusses the still limited knowledge on epigenetics in DS and describes the potential of epigenetic therapies to reverse dysregulated gene expression.


Subject(s)
Cognition Disorders/physiopathology , Down Syndrome/physiopathology , Epigenesis, Genetic , Memory Disorders/physiopathology , Alzheimer Disease/genetics , Alzheimer Disease/physiopathology , Animals , Cognition Disorders/drug therapy , Cognition Disorders/genetics , Down Syndrome/drug therapy , Down Syndrome/genetics , Epigenesis, Genetic/drug effects , Humans , Memory Disorders/drug therapy , Memory Disorders/genetics
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