Improving Memory and Cognition in Individuals with Down Syndrome

Health in Down syndrome: creating a conceptual model

BACKGROUND

Down syndrome (DS) has a unique medical and psychological profile that could impact how health is defined on three dimensions: physical, social and mental well-being.

METHODS

In 2021, we presented our proposed conceptual model to three expert panels, four focus groups of parents of individuals with DS age 0-21 years and four focus groups of individuals with DS age 13-21 years through videoconferencing technology. Participants gave feedback and discussed the concept of health in DS.

RESULTS

Feedback from participants resulted in iterative refinement of our model, retaining the three dimensions of health, and modifying constructs within those dimensions. Experts and parents agreed that individuals with DS have unique health concerns that necessitate the creation and validation of a syndrome-specific health model. We present key themes that we identified and a final conceptual model of health for individuals with DS.

CONCLUSION

Health in DS is a multi-dimensional, multi-construct model focused on relevant constructs of causal and effect indicators. This conceptual model can be used in future research to develop a syndrome-specific measure of health status.

Indicators of health in Down syndrome: A virtual focus group study with patients and their parents

BACKGROUND

Down syndrome has a unique medical and psychological profile. To date, few studies have asked individuals with Down syndrome about their views of health.

METHODS

Eight focus groups of 20 parents and 8 individuals with Down syndrome, were conducted virtually via videoconferencing to obtain participants' views of health indicators. Focus group moderators employed some modifications for individuals with Down syndrome, including simplified language and use of graphics. Transcripts were coded using a hybrid inductive/deductive framework and thematically analysed using the Framework Method.

RESULTS

We describe lessons learned in conducting virtual focus groups of individuals with Down syndrome and their parents. Individuals with Down syndrome could describe their views of health indicators and identified many of the same topics as their parents. Both groups discussed physical, mental, and social health components. However, people with Down syndrome gave a more restricted range of examples, but with different nuances than parents.

CONCLUSION

Partcipants discussed physical, social, and mental well-being components of health in Down syndrome. Interviewing individuals with Down syndrome in virtual focus groups with appropriate modifications added important self-report health information.

Tiny Toes to Tau Tangles: Down's Syndrome and Its Association With Alzheimer's Disease

Down’s syndrome (DS) is a common genetic condition caused by the trisomy of chromosome 21, which leads to the development of many multisystemic complications, early-onset Alzheimer’s disease (AD) being one of its most common complications. In this article, we have performed an intensive literature review that established a strong relationship between AD and DS. These two conditions are clubbed pathologically, clinically, and diagnostically to understand the association between AD and DS. This article focuses on understanding the impact of AD on a DS patient on both clinical and pathological levels and exploring some advanced treatment modalities. It has also emphasized the importance of early screening and diagnosis for AD in this group of patients to prevent AD development. Regular monitoring, early diagnosis, and a proper treatment plan can slow the AD occurrence in DS patients.

Parent Attitudes Toward Enhancing Cognition and Clinical Research Trials in Down Syndrome: A Mixed Methods Study

OBJECTIVE

As understanding of the neurobiological basis of cognitive impairment in Down syndrome (DS) advances and new pharmaceutical interventions targeting neurodevelopment become available, an in-depth understanding of the family perspective is essential to inform research efforts. A mixed methods study was conducted with parents of individuals with DS to learn about attitudes toward pharmacological interventions to enhance cognition, participation in clinical research trials in DS, and the relationship between child/family-specific factors and parent attitudes.

METHOD

Parents completed an online survey (N = 37) assessing family/child sociodemographic factors and to capture thoughts on cognitive enhancement and participation in clinical drug trials. A subset of interested parents participated in a follow-up phone interview (N = 21) or focus group (N = 3; 1 FG). Double-blind thematic analysis was used to analyze qualitative data.

RESULTS

Parents' attitudes toward improving cognition, reversing intellectual disability, and participation in clinical trials correlated with each other and were informed by specific parent and child factors (e.g., child attention-deficit hyperactivity disorder/behavioral diagnosis and parent education). Qualitative themes included advantages, disadvantages, and ethical implications of enhancing cognition. In addition, themes emerged regarding the need to understand the mechanism and potential side effects of experimental drugs, logistical factors relating to willingness to participate in clinical trials, and the evolution of parents' attitudes over time.

CONCLUSION

The findings highlight the complexity of issues and implications of clinical trials for enhancing cognition in DS. Child-specific factors, logistical and safety considerations, and personal belief systems all inform parent attitudes and decision making. The findings reflect the importance of incorporating parent perspectives and values in research direction and design.

Piloting the use of global health measures in a Down syndrome clinic

PURPOSE

People with Down syndrome (DS) have a unique medical profile which may impact views of health. We aimed to explore the use of global health measures in DS.

METHODS

Prospective survey in the Mass General Hospital Down Syndrome Program (MGH DSP) from December 2018 to July 2019 with Patient Reported Outcomes Measurement Information System (PROMIS)® instruments of global health. Analyses included use of scoring manuals, descriptive statistics and dependent samples t test.

RESULTS

Seventeen adolescents, 48 adults with DS and 88 caregivers returned surveys; 137 were complete. Incomplete responses and notes showed limitations of the instruments in this population. Global health T-scores did not differ from the available comparative standardized scores to these measures from PROMIS® reference population (p > 0.05).

CONCLUSIONS

In the MGH DSP, pilot global health instruments were completed by some adults with DS and caregivers, with some limitations and scores similar to the PROMIS® reference population.

The Role of HSA21 Encoded Mirna in Down Syndrome Pathophysiology:Opportunities in miRNA-Targeted Pharmacotherapy and Diagnosis of the Down Syndrome

Trisomy 21 is the most prevalent aneuploidy disorder among live-born children worldwide. Itresults from the presence of an extra copy of chromosome 21 which leads to a wide spectrum ofpathophysiological abnormalities and intellectual disabilities. Nevertheless human chromosome21 (HSA21) possess protein non-coding regions where HAS-21 derived-microRNA genes aretranscribed from. In turn, these HSA21-derived miRNAs curb protein translation of severalgenes which are essential to meet memory and cognitive abilities. From the genetics andmolecular biology standpoints, dissecting the mechanistic relationship between DS pathology/symptoms and five chromosome 21-encoded miRNAs including miR-99a, let-7c, miR-125b-2,miR-155 and miR-802 seems pivotal for unraveling novel therapeutic targets. Recently,several studies have successfully carried out small molecule inhibition of miRNAs function,maturation, and biogenesis. One might assume in the case of DS trisomy, the pharmacologicalinhibition of these five overexpressed miRNAs might open new avenues for amelioration of theDS symptoms and complications. In this review, we primarily elucidated the role of HSA21-encoded miRNAs in the DS pathology which in turn introduced and addressed importanttherapeutic targets. Moreover, we reviewed relevant pharmaceutical efforts that based theirgoals on inhibition of these pathological miRNAs at their different biogenesis steps. We havealso discussed the challenges that undermine and question the reliability of miRNAs as noneinvasivebiomarkers in prenatal diagnosis.

The AT(N) framework for Alzheimer's disease in adults with Down syndrome

The National Institute on Aging in conjunction with the Alzheimer's Association (NIA-AA) recently proposed a biological framework for defining the Alzheimer's disease (AD) continuum. This new framework is based upon the key AD biomarkers (amyloid, tau, neurodegeneration, AT[N]) instead of clinical symptoms and represents the latest understanding that the pathological processes underlying AD begin decades before the manifestation of symptoms. By using these same biomarkers, individuals with Down syndrome (DS), who are genetically predisposed to developing AD, can also be placed more precisely along the AD continuum. The A/T(N) framework is therefore thought to provide an objective manner by which to select and enrich samples for clinical trials. This new framework is highly flexible and allows the addition of newly confirmed AD biomarkers into the existing AT(N) groups. As biomarkers for other pathological processes are validated, they can also be added to the AT(N) classification scheme, which will allow for better characterization and staging of AD in DS. These biological classifications can then be merged with clinical staging for an examination of factors that impact the biological and clinical progression of the disease. Here, we leverage previously published guidelines for the AT(N) framework to generate such a plan for AD among adults with DS.

Dementia in Down syndrome: unique insights for Alzheimer disease research

Virtually all adults with Down syndrome (DS) show the neuropathological changes of Alzheimer disease (AD) by the age of 40 years. This association is partially due to overexpression of amyloid precursor protein, encoded by APP, as a result of the location of this gene on chromosome 21. Amyloid-β accumulates in the brain across the lifespan of people with DS, which provides a unique opportunity to understand the temporal progression of AD and the epigenetic factors that contribute to the age of dementia onset. This age dependency in the development of AD in DS can inform research into the presentation of AD in the general population, in whom a longitudinal perspective of the disease is not often available. Comparison of the risk profiles, biomarker profiles and genetic profiles of adults with DS with those of individuals with AD in the general population can help to determine common and distinct pathways as well as mechanisms underlying increased risk of dementia. This Review evaluates the similarities and differences between the pathological cascades and genetics underpinning DS and AD with the aim of providing a platform for common exploration of these disorders.

Cognitive decline and dementia in Down syndrome

PURPOSE OF REVIEW

Alzheimer's disease is most likely universal in older individuals with Down syndrome, due to having three copies of the amyloid precursor protein gene, resulting in amyloid-beta plaque deposition. Down syndrome is an important population in which to consider clinical trials of treatments to prevent or delay the development of dementia. However, assessment of subtler cognitive changes is challenging due to the presence of intellectual disability.

RECENT FINDINGS

Recent research confirmed that older adults with Down syndrome often present with cognitive decline: more than 80% may experience dementia by age 65 years. Efforts have been made to improve and validate neuropsychological assessment and to describe the relationship with comorbidities such as epilepsy and haemorrhagic stroke. There have also been advances in biomarkers such as neuroimaging using amyloid PET.

SUMMARY

Clinical trials of treatments, particularly in the presymptomatic phase of Alzheimer's disease, are important to consider in individuals with Down syndrome given their high dementia burden, and may also serve as proof of concept for other forms of Alzheimer's disease. However, further work is required to improve outcome measures and better understand the biomarkers of progression of disorder and their relationship with symptom development during the presymptomatic period.