CDKL5 Disorder | Symptoms

What are the symptoms of CDKL5 disorder?

While every child with CDKL5 disorder is different in terms of physical symptoms and developmental milestones met, the condition includes a number of common identifiable features:

  • Early-onset epilepsy
    • 90 percent of children with CDKL5 disorder will develop seizures before 3 months of age.
    • This commonly includes epileptic spasms, though they may not be the first seizure type.
    • Seizures with multiple distinct phases are common (such as the hypermotor-tonic-spasms sequence).
  • Impaired gross motor skills (such as walking)
  • Impaired fine motor skills (such as grasping)
  • Global developmental delays and intellectual disability
  • Impaired language/communication and social skills
  • Autistic features (though many children don’t meet formal criteria for autism spectrum disorder)
  • Low muscle tone
  • Poor eye contact and visual fixation; often with cortical visual impairment (difficulty interpreting vision in the brain, but the eyes are structurally normal)
  • Sleep abnormalities
  • Swallowing and feeding difficulties
  • Growth restriction
  • Gastrointestinal reflux and/or constipation
  • Scoliosis, hip dysplasia or other orthopedic complications from low muscle tone
  • Development of high muscle tone in the legs over time

Less common features of CDKL5 disorder

  • Microcephaly (small head size)
  • Subtle characteristic facial features including broad or prominent forehead, large deep-set eyes, and/or full lips.
  • Stereotypic movements or movement disorders
  • Features overlapping with Rett syndrome and other neurodevelopmental disorders, including cold hands and feet, unexplained laughing or screaming spells, irregular breathing (periods of fast or slow breathing) and teeth grinding.