Mutations in the CDKL5 (cyclin-dependent kinase-like 5) gene cause CDKL5 Deficiency Disorder (CDD), a severe neurodevelopmental syndrome where patients exhibit early-onset seizures, intellectual disability, stereotypies, limited or absent speech, autism-like symptoms and sensory impairments.
Progressive transition from this seizure type to epileptic spasms in clusters seems to result from increasing expression of the CDKL5 gene, as the child grows older.
Pathogenic mutations in cyclin-dependent kinase-like 5 (<i>CDKL5</i>) result in CDKL5 deficiency disorder (CDD), a rare disease marked by early-life seizures, autistic behaviors, and intellectual disability.
In addition to a FOXG1 mutation in a patient with all core features of the congenital variant of RTT, we identified a missense (p.Ser240Thr) in CDKL5 in a patient who appeared to be seizure free.
These data indicate that CDKL5 plays an important role in controlling postsynaptic localization of the GluN2B-SAP102 complex in the hippocampus and thereby regulates seizure susceptibility, and that aberrant NMDA receptor-mediated synaptic transmission underlies the pathological mechanisms of the CDKL5 loss-of-function.
The cyclin-dependent kinase-like 5 (CDKL5) gene has been associated with rare neurodevelopmental disorders characterized by the early onset of seizures and intellectual disability.
The common features of all female patients with CDKL5 gene mutations included refractory seizures starting before 4 months of age, severe psychomotor retardation, Rett-like features such as hand stereotypies, deceleration of head growth after birth and poor prognosis.
Mutations in the CDKL5 gene have been associated with the early-onset seizure variant of Rett syndrome and mutations in FOXG1 have been associated with the congenital Rett syndrome variant.
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.
Mutations in cyclin-dependent kinase like 5 (CDKL5) and FoxG1 genes have been identified in the early onset seizure and the congenital variants respectively.
Mutations in the CDKL5 (cyclin-dependent kinase-like 5) gene are associated with a severe epileptic encephalopathy (early infantile epileptic encephalopathy type 2, EIEE2) characterized by early-onset intractable seizures, infantile spasms, severe developmental delay, intellectual disability, and Rett syndrome (RTT)-like features.
Mutations in the cyclin-dependent kinase-like 5 gene (CDKL5) located in the Xp22 region have been shown to cause a subset of atypical Rett syndrome with infantile spasms or early seizures starting in the first postnatal months.
Recent studies have shown that aberrations of CDKL5 in female patients cause early-onset intractable seizures, severe developmental delay or regression, and Rett syndrome-like features.
Development of early onset seizure was a characteristic clinical feature for the patients with CDKL5 alterations in both genders despite polymorphous seizure types, including myoclonic seizures, tonic seizures, and spasms.
Mutations in CDKL5 have been identified both in females with the early onset seizure variant of RTT and in males with X-linked epileptic encephalopathy.
The clinical sensitivity of CDKL5 mutation screening among females with Rett-like features and negative MECP2 screening was 7.8% while the clinical sensitivity among females having cryptogenic intractable seizures with an onset before the ages of 12, 6 and 3 months were 4.7, 11.6 and 14.3%, respectively.
We report the first case of an exonic deletion of CDKL5 in a male and emphasize the importance of underappreciated mosaic exonic copy number variation in patients with early-onset seizures and RTT-like features of both genders.
Mutations of the X-linked gene cyclin-dependent kinase-like 5 (CDKL5) cause an X-linked encephalopathy with early onset intractable epilepsy, including infantile spasms and other seizure types, and a Rett syndrome (RTT)-like phenotype.
In conclusion, our report suggests that searching for large rearrangements in CDKL5 should be considered in girls with early onset seizures and Rett-like features.