@article {560, title = {Loss of tubulin deglutamylase CCP1 causes infantile-onset neurodegeneration.}, journal = {EMBO J}, volume = {37}, year = {2018}, month = {2018 Dec 03}, abstract = {

A set of glutamylases and deglutamylases controls levels of tubulin polyglutamylation, a prominent post-translational modification of neuronal microtubules. Defective tubulin polyglutamylation was first linked to neurodegeneration in the () mouse, which lacks deglutamylase CCP1, displays massive cerebellar atrophy, and accumulates abnormally glutamylated tubulin in degenerating neurons. We found biallelic rare and damaging variants in the gene encoding CCP1 in 13 individuals with infantile-onset neurodegeneration and confirmed the absence of functional CCP1 along with dysregulated tubulin polyglutamylation. The human disease mainly affected the cerebellum, spinal motor neurons, and peripheral nerves. We also demonstrate previously unrecognized peripheral nerve and spinal motor neuron degeneration in mice, which thus recapitulated key features of the human disease. Our findings link human neurodegeneration to tubulin polyglutamylation, entailing this post-translational modification as a potential target for drug development for neurodegenerative disorders.

}, issn = {1460-2075}, doi = {10.15252/embj.2018100540}, author = {Shashi, Vandana and Magiera, Maria M and Klein, Dennis and Zaki, Maha and Schoch, Kelly and Rudnik-Sch{\"o}neborn, Sabine and Norman, Andrew and Lopes Abath Neto, Osorio and Dusl, Marina and Yuan, Xidi and Bartesaghi, Luca and De Marco, Patrizia and Alfares, Ahmed A and Marom, Ronit and Arold, Stefan T and Guzm{\'a}n-Vega, Francisco J and Pena, Loren Dm and Smith, Edward C and Steinlin, Maja and Babiker, Mohamed Oe and Mohassel, Payam and Foley, A Reghan and Donkervoort, Sandra and Kaur, Rupleen and Ghosh, Partha S and Stanley, Valentina and Musaev, Damir and Nava, Caroline and Mignot, Cyril and Keren, Boris and Scala, Marcello and Tassano, Elisa and Picco, Paolo and Doneda, Paola and Fiorillo, Chiara and Issa, Mahmoud Y and Alassiri, Ali and Alahmad, Ahmed and Gerard, Amanda and Liu, Pengfei and Yang, Yaping and Ertl-Wagner, Birgit and Kranz, Peter G and Wentzensen, Ingrid M and Stucka, Rolf and Stong, Nicholas and Allen, Andrew S and Goldstein, David B and Schoser, Benedikt and R{\"o}sler, Kai M and Alfadhel, Majid and Capra, Valeria and Chrast, Roman and Strom, Tim M and Kamsteeg, Erik-Jan and B{\"o}nnemann, Carsten G and Gleeson, Joseph G and Martini, Rudolf and Janke, Carsten and Senderek, Jan} } @article {503, title = {Somatic SLC35A2 variants in the brain are associated with intractable neocortical epilepsy.}, journal = {Ann Neurol}, volume = {83}, year = {2018}, month = {2018 Jun}, pages = {1133-1146}, abstract = {

OBJECTIVE: Somatic variants are a recognized cause of epilepsy-associated focal malformations of cortical development (MCD). We hypothesized that somatic variants may underlie a wider range of focal epilepsy, including nonlesional focal epilepsy (NLFE). Through genetic analysis of brain tissue, we evaluated the role of somatic variation in focal epilepsy with and without MCD.

METHODS: We identified somatic variants through high-depth exome and ultra-high-depth candidate gene sequencing of DNA from epilepsy surgery specimens and leukocytes from 18 individuals with NLFE and 38 with focal MCD.

RESULTS: We observed somatic variants in 5 cases in SLC35A2, a gene associated with glycosylation defects and rare X-linked epileptic encephalopathies. Nonsynonymous variants in SLC35A2 were detected in resected brain, and absent from leukocytes, in 3 of 18 individuals (17\%) with NLFE, 1 female and 2 males, with variant allele frequencies (VAFs) in brain-derived DNA of 2 to 14\%. Pathologic evaluation revealed focal cortical dysplasia type Ia (FCD1a) in 2 of the 3 NLFE cases. In the MCD cohort, nonsynonymous variants in SCL35A2 were detected in the brains of 2 males with intractable epilepsy, developmental delay, and magnetic resonance imaging suggesting FCD, with VAFs of 19 to 53\%; Evidence for FCD was not observed in either brain tissue specimen.

INTERPRETATION: We report somatic variants in SLC35A2 as an explanation for a substantial fraction of NLFE, a largely unexplained condition, as well as focal MCD, previously shown to result from somatic mutation but until now only in PI3K-AKT-mTOR pathway genes. Collectively, our findings suggest a larger role than previously recognized for glycosylation defects in the intractable epilepsies. Ann Neurol 2018.

}, issn = {1531-8249}, doi = {10.1002/ana.25243}, author = {Winawer, Melodie R and Griffin, Nicole G and Samanamud, Jorge and Baugh, Evan H and Rathakrishnan, Dinesh and Ramalingam, Senthilmurugan and Zagzag, David and Schevon, Catherine A and Dugan, Patricia and Hegde, Manu and Sheth, Sameer A and McKhann, Guy M and Doyle, Werner K and Grant, Gerald A and Porter, Brenda E and Mikati, Mohamad A and Muh, Carrie R and Malone, Colin D and Bergin, Ann Marie R and Peters, Jurriaan M and McBrian, Danielle K and Pack, Alison M and Akman, Cigdem I and LaCoursiere, Christopher M and Keever, Katherine M and Madsen, Joseph R and Yang, Edward and Lidov, Hart G W and Shain, Catherine and Allen, Andrew S and Canoll, Peter D and Crino, Peter B and Poduri, Annapurna H and Heinzen, Erin L} }