CDKL5. The next gene in our weekly review of known epilepsy genes is CDKL5. Even though CDKL5 is one of the most common genes for epileptic encephalopathies, we have never really featured this gene on our blog. Let’s catch up with a brief post on what you need to know about CDKL5 in 2015. Continue reading
Inducible. Next generation sequencing technologies have the tremendous potential to identify disease-causing genes in a hypothesis-free manner. In a recent publication in the American Journal of Human Genetics, mutations in the gene for the salt-inducible kinase 1 (SIK1) are found in patients with early onset epileptic encephalopathy. In addition to a previously unknown functional network related to intracellular salt in the CNS, the authors demonstrate a peculiar mutational mechanism – activating truncation mutations. Continue reading
Exome failures. Trio exome sequencing has the huge potential to discover the genetic basis of neurodevelopmental disorders. However, the results are negative for the majority of patients. In a recent study published in Nature, genome sequencing was applied to exome-negative patients with intellectual disability, identifying mutations in coding regions that were previously missed. But are the authors correct in stating that they can explain more than 60% of cases in an unselected cohort? Continue reading
A growing number of genes have been identified to be causative for genetic forms of epilepsy, which are neither ion channels, receptors nor other classical epilepsy genes but epigenetic players. The epigenetic enzymes and effector proteins described to be mutated in inherited genetic epilepsies as well as epileptic encephalopathies, intellectual disability syndromes and autism spectrum disorders with associated severe or occasional seizure phenotype are of various function. Since this function never seems to be sufficiently discussed in the respective publications and little is to be found on how these genes may be linked to the phenotype, here comes a little overview summarizing how epigenetics is contributing not only to symptomatic focal epilepsy but may also help to explain the phenotypic heterogeneity of genetic epilepsies.