CDKL5 Disorder
Also known as: CDKL5 deficiency, STK9
What is CDKL5 disorder?
CDKL5 (Cyclin-Dependent Kinase-Like 5) is a gene located on the X-chromosome. The CDKL5 gene is required to function normally for a normal brain to develop. While most children affected with this rare genetic disorder are girls (5 times more common), when boys are affected, they have more severe abnormalities.
CDKL5 mutations have been found in a number of children with a spectrum of neurological disorders.
What causes CDKL5 disorder?
The gene change that underlies this disorder occurs spontaneously (a mutation) and is not passed down through families, in most cases.
What are the symptoms of CDKL5 disorder?
Seizures begin early in life (usually first 3-6 months). Problems with brain development can lead to:- Severe developmental delay
- Typical repetitive hand movements (e.g. hand wringing)
- Poor muscle tone
- Inability to walk, talk or feed themselves (epileptic encephalopathy)
- Curved spine
- Problems with breathing and heart
- Gastrointestinal problems
- And other issues.
What are CDKL5 disorder care options?
As there is no cure or specific treatment, early seizure control (frequently challenging) and symptomatic and supportive management by a multidisciplinary team which includes physical therapy, occupational therapy and speech and augmentative communication will maximize your child's abilities.
Reviewed by: Jack Wolfsdorf, MD, FAAP
This page was last updated on: September 16, 2025 12:18 PM
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