Forkhead. In our Epilepsiome series we are reviewing all major epilepsy genes. This week, we discuss FOXG1, a gene previously described as the cause for a congenital variant of Rett Syndrome. However, since its initial discovery in 2008, a much broader spectrum has been recognized. FOXG1 syndrome typically includes developmental delay and microcephaly. Many patients have severe, early-onset epilepsy and a prominent hyperkinetic movement disorder. In addition, some patients have brain malformations. Here is a brief introduction to our Epilepsiome review of FOXG1, an epilepsy gene that stands out from other causes of genetic epilepsies given its prominent role in forebrain development.
Rett. We have written very little about MECP2 on Beyond the Ion Channel. MECP2 is the gene for Rett Syndrome, a neurodegenerative disorder almost exclusively affecting females. Classical Rett Syndrome is characterized by developmental regression in the first two years of life and the development of distinctive hand movements, which historically led to Rett Syndrome being considered a recognizable entity. This blog post is the introduction to our MECP2 Epilepsiome page. However, in 2016, a time when many genes are re-defined by exome studies, I was wondering whether Rett Syndrome is still the classical syndrome that I initially learned about.
The sugar code. Many proteins in the human body undergo post-translational modification. A common mechanism to modify the function of proteins is a process called glycosylation, the adding of carbohydrate residues to protein. Glycosylation is probably the most complex post-translational modification, critically important to various physiological functions and therefore tightly regulated in cells. Accordingly, genetic disorders that interfere with glycosylation may present as severe, multisystem disorders. However, it is increasingly recognized that many congenital disorders of glycosylation have an exclusively neurological phenotype. Here is an update on ALG13 epileptic encephalopathy, a recently identified disease entity that may account for up to 2% of Infantile Spasms in females. Continue reading
Pyridoxine. I still remember when I learned about vitamin B6 deficient epilepsy in medical school. One of the residents quizzed me about the first medication to given to a seizing neonate. I suggested phenobarbital, but he shook his head and said “vitamin B6” – which was something that I had never really heard about before. Technically, pyridoxine is not the first-line treatment in neonatal seizures on most protocols, but vitamin-dependent epilepsies are always on the differential in newborns with seizures. Here are a few things about ALDH7A1 that are new in 2016. Continue reading
Prague. I am sitting in my hotel in Dublin on my way back to Philadelphia, trying to collect my thoughts on last week’s European Epilepsy Congress in Prague. For both Katie and me, it was great to catch up with our colleagues from Europe and Australia. For our European RES consortium, this meeting was an important inflection point – in fact, three years after the end of the funding period, RES is alive and kicking. Here are the five things I learned in the City of the Hundred Spires. Continue reading
HSP. I have to admit that the hereditary spastic paraplegias are not mentioned all that frequently on our blog. The main reason is that there is little overlap between early-onset epilepsies and adult-onset progressive neurodegenerative conditions that are characterized by spasticity and weakness in the lower extremities. In a recent publication, we described an epilepsy gene that became an HSP gene, showing an unusual overlap between both groups of conditions and establishing a novel mechanism in HSP pathogenesis. Here is a continuation of the KCNA2 story. Continue reading
Duality. Earlier this week, our Luxembourg collaborators came to visit us at CHOP to discuss our current and future projects. We discussed potential overlaps between the diseases that both our groups are mainly involved in, namely Parkinson’s disease and genetic epilepsies. In fact, we had just published on one of the overlapping genes recently, a gene that we accidentally stumbled upon through our genome sequencing projects. Here is the story of SYNJ1, a gene involved in neurodegenerative phenotypes that link early-onset Parkinson’s disease and epileptic encephalopathy. Continue reading
Inhibition. GABA is the main inhibitory neurotransmitter in the the Central Nervous System. Given that epilepsy is typically associated with increased excitability, all mechanisms related to GABA signaling are of natural interest to the epilepsy community. Almost 15 years ago, mutations in GABRA1, coding for alpha-1 subunit of the GABA-A receptor, have been identified in familial Juvenile Myoclonic Epilepsy, but there has been relative silence around this gene since. Now, two publications highlight the other side of GABRA1 as a gene for epileptic encephalopathies, putting the GABA receptor into the spotlight again.
Completed. Last week, we completed the recruitment for one of the more visionary projects at CHOP that we are involved in – the epilepsy pilot project of the Genomics Research and Innovation Network (GRIN), a collaboration between CHOP, Boston Children’s Hospital, and Cincinnati Children’s Hospital. Here is my personal take on GRIN and why I think that forming, building, and expanding GRIN is so important in our current research environment. Continue reading
SCN2A. Last Thursday, I hopped on a plane to Chicago to join the first FamilieSCN2a Foundation Conference. SCN2A, one of the most common genes in genetic epilepsies, has emerged as a gene with a broad range of phenotypes, which makes understanding this gene relatively complicated. I am very happy that the SCN2A community is currently coming together to provide a platform for patient initiatives and connections to clinicians and researchers. Here is my list of five things I learned about the genetic shape-shifter in Chicago. Continue reading