RecruitingNCT06585605
Neurological
CDKL5 Deficiency Disorder
Also known as CDD, CDKL5 epileptic encephalopathy, early-onset seizure variant of Rett syndrome, X-linked infantile spasm syndrome
CDKL5 deficiency disorder is caused by mutations in CDKL5 (cyclin-dependent kinase-like 5), an X-linked gene encoding a kinase critical for synapse formation and function. Onset occurs in the first months of life with seizures that are typi
ORPHA:505652 ↗Gene CDKL5Prevalence 1-9 per 100,000 (Orphanet)Onset InfantileX-linked dominant genetic (de novo in most cases)
3
studies recruiting now
as of 7 Sept 2026
26
studies registered in total
as of 7 Sept 2026
2
countries with a recruiting site
as of 7 Sept 2026
13 May 2025
most recent study posted
among recruiting studies
Recruiting trials
RecruitingNCT06967727
Registry and Natural History of Epilepsy-Dyskinesia Syndromes
RecruitingNCT05558371
International CDKL5 Clinical Research Network
Showing the 3 most recently updated recruiting studies, as recorded 7 Sept 2026. Live status on each study page.
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Countries with at least one recruiting site among the studies above, 7 Sept 2026. Tap a country to search trials there.
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About CDKL5 Deficiency Disorder
CDKL5 deficiency disorder is caused by mutations in CDKL5 (cyclin-dependent kinase-like 5), an X-linked gene encoding a kinase critical for synapse formation and function. Onset occurs in the first months of life with seizures that are typically severe, frequent, and highly refractory to antiseizure medications. Additional features include hypotonia, absence of purposeful hand use, limited or absent speech, and stereotyped hand movements. While previously considered a Rett variant, CDD is now recognized as a distinct disorder.
Common clinical features
Early-onset refractory seizuresHypotoniaAbsent or limited hand useAbsent speechCortical visual impairmentStereotyped hand movementsScoliosis
From Orphanet’s phenotype annotations (CC BY 4.0). Not a complete list.
Treatments being studied
1 in clinical development, from Open Targets (CC BY 4.0). Not medical advice.
Phase 3Ganaxolone (Ztalmy)
Before you apply
Things trial teams commonly ask about for CDKL5 Deficiency Disorder. Not eligibility rules; those are set by each study.
- CDKL5 pathogenic variant confirmed on sequencing (hemizygous in males, heterozygous in females) is required for all trials
- Baseline seizure frequency diary over minimum 3 months documenting seizure types and frequency is required
- Prior antiseizure medication trials (number and response) are documented to confirm refractory status for interventional trials
- CDKL5-specific functional assessment tools (CSBS, Bayley-III adapted, CDD-specific scales) are the primary outcome measures
Related conditions
Information, not medical advice. Trial listings are shown as recorded on ClinicalTrials.gov; whether any study is right for you is a decision for you and your clinicians, and eligibility is decided by each research team. Disease information from Orphanet (CC BY 4.0).