Salt matters – SIK1 in epileptic encephalopathies

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

Less is more – gene identification in epileptic encephalopathies through targeted resequencing

Exome no more. Over the last 15 months, we have repeatedly discussed how exome sequencing or genome sequencing is applied to neurodevelopmental disorders in order to discover new candidate genes and to assess the role of known candidate genes. We have also wondered sometimes whether exome sequencing is the most straightforward approach. Now – outpacing the two large international consortia using exome sequencing in epileptic encephalopathies – a recent study in Nature Genetics uses a different approach to uncover the genetic basis in 10% of patients with epileptic encephalopathies.  Targeted resequencing or gene panel analysis is a hybrid technology between candidate gene sequencing and next generation sequencing and focuses only on a subset of candidate genes. While their study provides a comprehensive overview over the genetics of rare epilepsy syndromes, it raises the question whether the era of large-scale exome sequencing is coming to a natural end. Continue reading