Building the Future Therapies for Down Syndrome: The Third International Conference of the T21 Research Society

Long-Term Non-Congenital Cardiac and Renal Complications in Down Syndrome: A Study of 32,936 Patients

BACKGROUND

Individuals with Down syndrome are at a higher risk of cardiac, renal, and other health issues due to a complex disease physiology. However, few data exist on long-term disease risks to guide prevention and care. We aimed to determine the 10-year incidence of cardiac, renal, and urinary tract complications in Down syndrome versus matched controls.

METHODS

This retrospective cohort study utilized a large collaborative database. We identified 32,444 patients with Down syndrome and matched controls, excluding those with pre-follow-up target events. Covariates included demographics, lifestyle factors, and comorbidities. Outcomes were ischemic heart disease, hypertension, hypothyroidism, epilepsy, urinary tract infections and chronic kidney disease. We calculated unadjusted and adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) using Cox regression and plotted Kaplan-Meier survival curves.

FINDINGS

Over 10 years, Down syndrome patients showed a 3.7-fold higher ischemic heart disease risk (95% CI: 3.0-4.6) and a 1.6-fold higher hypertension risk (95% CI: 1.4-1.8) versus controls. Hypothyroidism (HR = 2.0; 95% CI: 1.7-2.4), epilepsy (HR = 4.5; 95% CI: 3.5-5.8), and urinary tract infection (HR = 3.9; 95% CI: 3.4-4.6) risks were also higher. Chronic kidney disease risk was 2.7-fold greater (95% CI: 2.1-3.5). Survival analysis confirmed a significantly higher incidence of all outcomes in Down syndrome (p < 0.0001).

INTERPRETATION

This large study found major health challenges in Down syndrome, with risks 3- to 5-fold higher for chronic conditions versus matched controls over 10 years. Though survival remains high with proper care, focusing resources on the prevention and management of complications in this high-risk group can optimize well-being across the lifespan. Future research accounting for limitations here would provide definitive estimates of disease risk in Down syndrome to guide targeted health strategies.

Expressive language sampling and outcome measures for treatment trials in fragile X and down syndromes: composite scores and psychometric properties

The lack of psychometrically sound outcome measures has been a barrier to evaluating the efficacy of treatments proposed for core symptoms of intellectual disability (ID). Research on Expressive Language Sampling (ELS) procedures suggest it is a promising approach to measuring treatment efficacy. ELS entails collecting samples of a participant's talk in interactions with an examiner that are naturalistic but sufficiently structured to ensure consistency and limit examiner effects on the language produced. In this study, we extended previous research on ELS by analyzing an existing dataset to determine whether psychometrically adequate composite scores reflecting multiple dimensions of language can be derived from ELS procedures administered to 6- to 23-year-olds with fragile X syndrome (n = 80) or Down syndrome (n = 78). Data came from ELS conversation and narration procedures administered twice in a 4-week test-retest interval. We found that several composites emerged from variables indexing syntax, vocabulary, planning processes, speech articulation, and talkativeness, although there were some differences in the composites for the two syndromes. Evidence of strong test-retest reliability and construct validity of two of three composites were obtained for each syndrome. Situations in which the composite scores would be useful in evaluating treatment efficacy are outlined.

Therapeutics for mitochondrial dysfunction-linked diseases in Down syndrome

Genome-wide deregulation contributes to mitochondrial dysfunction and impairment in oxidative phosphorylation (OXPHOS) mechanism resulting in oxidative stress, increased production of reactive oxygen species (ROS) and cell death in individuals with Down syndrome (DS). The cells, which require more energy, such as muscles, brain and heart are greatly affected. Impairment in mitochondrial network has a direct link with patho-mechanism at cellular and systemic levels at the backdrop of generalized metabolic perturbations in individuals with DS. Myriads of clinico-phenotypic features, including intellectual disability, early aging and neurodegeneration, and Alzheimer disease (AD)-related dementia are inevitable in DS-population where mitochondrial dysfunctions play the central role. Collectively, the mitochondrial abnormalities and altered energy metabolism perturbs several signaling pathways, particularly related to neurogenesis, which are directly associated with cognitive development and early onset of AD in individuals with DS. Therefore, therapeutic challenges for amelioration of the mitochondrial defects were perceived to improve the quality of life of the DS population. A number of pharmacologically active natural compounds such as polyphenols, antioxidants and flavonoids have shown convincing outcome for reversal of the dysfunctional mitochondrial network and oxidative metabolism, and improvement in intellectual skill in mouse models of DS and humans with DS.