CDKL5 (cyclin-dependent kinase-like 5) disorder is a rare genetic condition that was first identified in 2004. It is caused by mutations in the CDKL5 gene, which is found on the X-chromosome. Although many cases have been identified in boys, because of the location of the gene, this disorder mainly affects girls. The cause of a CDKL5 mutation and the incidence of CDKL5 disorder are not known at this time.
The CDKL5 gene provides instructions for making a protein that is essential for normal brain and neuron development. Although relatively little is known about the protein’s function, it may play a role in regulating the activity of other genes, including the MECP2 gene of Rett Syndrome. The CDKL5 protein acts as a kinase, which is an enzyme that changes the activity of other proteins by adding oxygen and phosphate atoms (a phosphate group) at specific positions. Researchers have not yet determined which proteins are targeted by the CDKL5 protein.
Most children affected by CDKL5 suffer from seizures that begin in the first hours, days, weeks, or months of life. Children who have been diagnosed with CDKL5 disorder may have seizures starting within hours of birth, or as late as 8 months to 2 years of age. Some mothers have described feeling seizures even in the prenatal period.
CDKL5 is a rare disorder, however, more children are being diagnosed as awareness of CDKL5 spreads. CDKL5 mutations have been found in children diagnosed with Infantile Spasms, West Syndrome, Lennox-Gastaut, Rett Syndrome, cerebral palsy, autism and intractable epilepsy of unknown origin. However, it is important to note that scientists and doctors do not know what causes CDKL5 mutations, or the full spectrum of CDKL5 disorders at this time. It is likely that there are many people affected by CDKL5 who have mild symptoms and no seizures. With continued research and awareness of CDKL5, we hope to build a more comprehensive understanding of the spectrum of this disorder, and continue the search for a desperately needed cure.