At least 50 disease-causing mutations in this gene have been discovered. Further confirmation that CDKL5 is an independent disorder with its own characteristics is provided by this study, published in April 2016, which concluded 'There were differences in the presentation of clinical features occurring in the CDKL5 disorder and in Rett syndrome, reinforcing the concept that CDKL5 is an independent disorder with its own distinctive characteristics'. At one time, mutations in the CDKL5 gene were said to cause a disorder called X-linked infantile spasm syndrome (ISSX) or West syndrome. but this research established CDKL5 disorder as a distinct clinical entity. Animal studies GSK3β inhibitors in Cdkl5 knockout (Cdkl5 -/Y) mice rescues hippocampal development and learning. Likewise, IGF-1 treatment in CDKL5 null mice restores synaptic deficits. Therapeutics Aside from novel therapies with limited availability, anticonvulsants are the mainstay of treatment for most affected people. These have limited efficacy, pointing to a strong need to develop new treatment strategies for patients. Some treatments might show efficacy in a relevant proportion of patients, such as valproic acid, vigabatrin, clobazam or sodium channel blockers, as well as ketogenic diet A clinical trial of Ataluren for nonsense mutations in CDKL5 and Dravet Syndrome has been announced. This same drug was approved by the UK's National Institute for Health and Care Excellence (NICE) for use in treating nonsense mutations in Duchenne muscular dystrophy. This drug did not show any efficacy in patients with CDKL5 mutations. Finally a CDKL5 protein replacement therapy is in development. Location The CDKL5 gene is located on the short (p) arm of the X chromosome at position 22. More precisely, the CDKL5 gene is located from base pair 18,443,724 to base pair 18,671,748 on the X chromosome. ICD-10 G40.42 See also Cyclin-dependent kinase Rett syndrome West syndrome CDKL5 deficiency disorder References Further reading External links Cure CDKL5 Disorder resources for Families and Professionals - based in the UK International Foundation for CDKL5 Research - based in the US CDKL5 Forum - a professional forum to share current research on CDKL5 and to stimulate peer-group discussion CDKL5 Foundation Netherlands - CDKL5 Foundation based in holland for research, information and collaboration EC 2.7.11