Pediatric Exploratory Research Study of EGCG Use and Safety (PERSEUS)

Medical evaluations of incidence, nature, severity and causality of Adverse Events and Serious Adverse Events (SAE).

The finding of an elevated alanine transaminase (ALT) or aspartate transaminase (AST) (>3xULN), elevated total bilirubin (>2xULN)

Elevated TSH (>10 microU/mL) or any decrease of free T4 below the lower limit of normal values (<0.8 ng/dL)

Serum creatinine will be measured at various time points and an increase exceeding x1.5 ULN (upper limit of normal values) that is confirmed by a repeat testing within 3 days.

Electroencephalogram recording to detect epileptiform abnormalities and/or seizure activity and/or pro-convulsive effects in pediatric participants, enabling a deeper understanding of the pharmacological effects of the intervention.

A QTcF (Fridericia's correction) value (mean of the three measurements) exceeding 500 ms when confirmed in repeat measurement within 15-30 minutes will be recorded as SAE.

A QTcF value exceeding a change from screening (mean of three time-matched measurements) of 60 ms when confirmed in repeat measurement within 15-30 minutes will be recorded as SAE.

Doppler echocardiogram is used to look at how blood flows through the heart chambers, heart valves, and blood vessels. The movement of the blood reflects sound waves to a transducer. The ultrasound computer then measures the direction and speed of the blood flowing through heart and blood vessels.

This measure is known as an ejection fraction or EF.

Assessed by Picture Naming (PN) (WPPSI-IV). It is a verbal Comprehension subtest. It has 24 items. The child should name the drawings shown in the stimulus book. PN measures expressive language, ability and language development. Range score 0-24. Higher score is better outcome.

Assessed by Receptive Vocabulary (RV)(WPPSI-IV). It is a verbal comprehension subtest. It has 31 items. The child selects the picture that best represents the word the examiner reads aloud. RV measures receptive language ability and language development. Range score 0-40. Higher score is better outcome.

Assessed by Sentence Repetition (NEPSY-II): This subtest is designed to assess the ability to repeat sentences of increasing complexity and length. The child is read a series of sentences and asked to recall each sentence immediately after it is presented. Range score 0-34. Higher score is better outcome.

Assessed by Picture memory (WPPSI-IV). This subtest measures visual WM. It has 35 items. The child views a stimulus page of pictures for a specified time and then selects these pictures from options on a response page, for which a set of stimuli is viewed and then recognized from among a set of responses. Range score 0-35. Higher score is better outcome.

Subjects are asked to generate as many words as possible in 1 minute belonging to the category of "animals". No range score. A higher score is better outcome.

Assessed by Cats & Dogs Test. 16 pictures presented on a single strip of card (two trials with two conditions, control and experimental-inhibition). Measures of task accuracy in the experimental inhibition trial (total number of correct responses, range score 0-16) and total time performance (in seconds) were included in the analyses.

Assessed by Dimensional Change Card Sort (DCCS). Sort a series of bivalent test cards, according to one dimension(colour) or another(shape). Range score 0-24, higher score is better outcome.

Assessed by Blocks Design(WPPSI-IV). It is a visual spatial subtest which has 17 items. It measures ability to analyze and synthesize abstract visual stimuli. Range score 0-34, higher score is better outcome.

Changes in adaptive behavior

• A. Communication domain: Sum of A1+A2+A3. Range Score 0-198
• A1. Receptive subdomain: Range Score 0-40
• A2. Expressive subdomain: Range Score 0-108
• A3. Written subdomain: Range Score 0-50
• B. Daily living skills domain: Sum of B1+B2+B3. Range Score 0-109
• B1. Personal subdomain: Range Score 0-82
• B2. Domestic subdomain: Range Score 0-48
• B3. Community subdomain: Range Score 0-88
• C. Socialization domain: Sum of C1+C2+C3. Range Score 0-180
• C1. Interpersonal relationships subdomain: Range Score 0-64
• C2. Play and leisure time subdomain: Range Score 0-62
• C3. Coping skills subdomain: Range Score 0-60
• Total score: Sum of A+B+C. Range Score 0-576

For all measures: a higher score is a better outcome

Dyrk1A and homocysteine (markers of efficacy); and Catechins and EGC concentrations (EGCG metabolites).

Exploratory biomarkers: determination of folate in blood samples

In the PERSEUS project spot urine samples will be collected to further evaluate the metabolome of subjects with Down syndrome, seeking biomarkers of treatment efficacy or those differentiating responders and non-responders. Analysis will be focused in the biosynthesis and metabolism of neurotransmitters, the kynurenine pathway and the hypothalamic-hypophyseal-adrenal axis.

Evaluating changes in executive performance. BRIEF-P is a widely used caregiver questionnaire of everyday skills reflective of abilities in the executive domain. It generates a range of scales, including scales specific to working memory and inhibitory control.Raw scores and T-scores will be derived for the following scales: inhibit, shift, emotional control, initiate, working memory, plan/organize, organization of materials and monitor.

Evaluating changes in memory performance. OMQ-PF is a 27-item questionnaire designed to ascertain parental perceptions about their child's memory function. All items are rated on a 5-point Likert (from 1- Strongly agree to 5-Strongly disagree OR 1- Never to 5- Always).

Evaluating Quality of life.

The PedsQL measurement model was designed to integrate the merits of generic and disease-specific instruments to evaluate quality of life. Three modules will be used:

• cognitive functioning scale module. Range score 0-100
• generic core module. Range score 0-100
• family impact module. Range score 0-100 For all measures: a higher score is a better outcome

Rebound effects after discontinuation of treatment measures: evaluating changes sleep disturbances.

CSHQ is a 22-item parent-report questionnaire that encompasses eight domains:

• bedtime resistance. Range score 0-36
• sleep behavior. Range score 0-24
• night waking. Range score 0-8
• morning wake up. 0-16 For all items except item 19, a higher score is a better outcome

Rebound effects after discontinuation of treatment measures: evaluating changes in disrupting behaviors.

The ABC-C is a 58-item rating scale used to assess maladaptive behaviors across five original dimensions or subscales (Items are evaluated on a four-point Liker scale ranging from 0 (not at all a problem) to 3 (the problem is severe in degree)).

• Irritability. Range score 0-45
• Hyperactivity. Range score 0-48
• Lethargy/Withdrawal. Range score 0-21
• Stereotypy. Range score 0-48
• Inappropriate Speech. Range score 0-12 For all measures: a higher score is a worst outcome

KIDMED index includes 16 questions based on the principles of the Mediterranean diet, where higher scores indicate greater adherence to healthy diet. Range score -4 -16.

This variable will be created by computing the sum of the Z-scores from tests that make up IDD-CHILD battery described in secondary outcome measures. No range score. A higher score is better outcome.