Cyclin-dependent kinase-like 5 (CDKL5) (CDKL5)

Cyclin-dependent kinase-like 5 (CDKL5) is a member of the CMGC family of serine/threonine kinases and is primarily expressed in the brain, where it plays a vital role in early neurodevelopment (UniProt: O76039). The protein is involved in regulating neuronal morphogenesis, dendritic arborization, and synaptic plasticity by phosphorylating various substrates, including MAP1S and DRP1 (PubMed: 28801496). Mutations in the CDKL5 gene, located on the X chromosome, lead to CDKL5 Deficiency Disorder (CDD), a rare and severe neurodevelopmental condition characterized by early-onset, refractory seizures and profound developmental delays (NIH: GARD). While traditional anti-epileptic drugs are often ineffective, ganaxolone (Ztalmy) was recently approved as a symptomatic treatment that modulates GABA-A receptors to reduce seizure frequency in CDD patients (FDA: 2022). Current therapeutic strategies are shifting toward disease-modifying approaches, such as gene therapy (e.g., TSHA-104) and enzyme replacement therapy, which aim to restore functional CDKL5 levels in the central nervous system. However, CDKL5 is a dosage-sensitive gene, meaning that both deficiency and overexpression can lead to neurological impairment, presenting a significant challenge for precision dosing in genetic interventions.

Other names

Serine/threonine-protein kinase 9STK9CDKL5 deficiency disorder associated proteinEIEE2

Restoration of kinase activity through gene replacement or enzyme replacement therapy; symptomatic management of seizures via GABA-A receptor positive allosteric modulation.