Mutations in the X-linked cyclin-dependent kinase-like 5 (CDKL5) gene have been identified in patients with atypical Rett syndrome, X-linked infantile spasms sharing common features of generally early-onset seizures and mental retardation.
X-linked cyclin-dependent kinase-like 5 (CDKL5 or STK9) has recently been implicated in atypical Rett and X-linked West syndromes, severe neurological disorders associated with mental retardation, loss of communication and motor skills and infantile spasms and seizures in predominantly females.
Recently, we showed that truncation of the X-linked cyclin-dependent kinase-like 5 (CDKL5/STK9) gene caused mental retardation and severe neurological symptoms in two female patients.