International CDKL5 Clinical Research Network

OTHER

No intervention.

No intervention administered as part of this study; observational only.

CDKL5 Deficiency Disorder (CDD) Clinical Severity Assessment - Clinician (CCSA-Clinician)

Time frame: 5 years

Measured by clinician rating of patient. Item scores are transformed to a scale of 0-100 and the total score is calculated as a mean item score. Higher scores indicate higher severity.

CDKL5 Deficiency Disorder (CDD) Clinical Severity Assessment - Caregiver (CCSA-Caregiver)

Time frame: 5 years

Measured by caregiver/parent rating of patient on a scale of 0-100 with a higher score indicating higher severity.

CDKL5 Deficiency Disorder (CDD) Development Questionnaire - Caregiver (CDQ-Caregiver)

Time frame: 5 years

Measured by caregiver/parent rating of patient on a scale of 0-100 with a higher score indicating higher severity.

Communication and Symbolic Behavior Scales - Developmental Profile Infant Toddler Checklist (CSBS-DP ITC)

Time frame: 5 years

Measured by caregiver/parent rating of patient on a 24-item questionnaire. Three composite scores and a total score can be derived. Items contribute to the 0-57 point scale for the total score with lower scores indicating concerns for communication skills.

Sleep Disorder Scale for Children (SDSC)

Time frame: 5 years

Measured by caregiver/parent rating of patient on a 26- Likert type item questionnaire. Scale goes from 0-39 with a higher score indicating higher severity of sleep disorder. Each subscale is scored through the summation of all the subscale items. Comparing scores were the normative data reported in the initial validation paper, z-scores and t-scores can be derived. The t-score enables scores to be dichotomized as within normal range or outside of normal range, compared to the general population.

Quality of Life Inventory - Disability (QI-Disability)

Time frame: 5 years

This is a quality of life measure for children with intellectual disability. The measure comprises 32 items that are rated on a five-point Likert scale and group into six subscales: physical health, positive emotions, negative emotions, social interactions, independence, and leisure and outdoors. Following transformation to a 100-point scale, item scores in each subscale are summed and divided by the number of items to give a subscale score. The mean of the six subscale scores is calculated to give the total QOL score.

CDKL5 Deficiency Disorder (CDD) Gross Motor (CDD-Motor)

Time frame: 5 years

This is a video measure of gross motor function, based on the Rett Syndrome Gross Motor Scale with additional items that enable measurement of head control and sitting. Parents are provided with a filming protocol, video clips are uploaded to the investigators, and data are coded according to a predetermined coding system.

CDKL5 Deficiency Disorder (CDD) Fine Motor (CDD-Hand)

Time frame: 5 years

This is a video measure of fine motor function based on the Rett Syndrome Hand Function Scale with additional instructions on filming for if the patient has Cortical Visual Impairment. Parents are provided with a filming protocol, video clips are uploaded to the investigators, and data are coded according to a predetermined coding system.

Electroencephalogram/Evoked Potentials (EEG/EP) characteristics in CDKL5 Deficiency Disorder.

Time frame: 5 years

Measured by correlations of EEG/EP with other study scales.

What is a clinical trial?

A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.

Is it safe to participate?

Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.

Will I be compensated?

Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.

Will I receive a placebo instead of treatment?

When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.

Can I leave a trial if I change my mind?

Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.

How long does a clinical trial last?

Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.