Among the hundreds of genes that are overrepresented in individuals with trisomy 21, a few are highly suspected to be at least partly responsible for cognitive impairment. One of those genes, DYRK1A, encodes an enzyme involved in the control of the operation of neuronal cells and brain development. Pioneering work, carried out by research teams led by Mara Dierssen, PhD (Barcelona, ​​Spain) and Jean Delabar (Paris, France), highlighted the role of DYRK1A in a popular trisomy 21 mouse model (Ts65Dn), which "mimics" Down syndrome in humans. In this animal model, the inhibition of DYRK1A has shown to improve cognitive performance. The TesDAD study, conducted by Dr. Dierssen and her colleague Rafael de La Torre, is evaluating the benefit of EGCG (epigallocathechine gallate), a green tea extract and natural enzyme inhibitor, on executive function and memory in those living with Down syndrome.

[WATCH A 2011 INTERVIEW WITH DR. DIERSSEN ON HER RESEARCH]

EGCG may also be effective in preventing dementia. In fact, EGCG seems to decrease the amount of amyloid plaques that accumulate in the brains of Alzheimer's patients. In testing on rats, long-term treatment with EGCG has shown to improve memory by inhibiting the misfolding of proteins that accumulate in their brains and damage their memory capacity. Thus, treatment with EGCG may possibly reduce the early onset of Alzheimer's disease in individuals living with Down syndrome.

Measuring the effects of treatment

In the TesDAD study, the effects of EGCG treatment versus placebo were measured by assessing cognitive performance on certain neuropsychological tests. Various biomarkers were also measured such as the oxidation of lipids, cholesterol, DYRK1A (plasma homocysteine, etc..). Patient monitoring was primarily undertaken by brain imaging techniques.

The initial study was concluded in late 2013 and the data has been submitted for review. Results of the clinical research will be published in 2015 and follow up studies are being planned.