@article {520, title = {Biallelic Mutations in ADPRHL2, Encoding ADP-Ribosylhydrolase 3, Lead to a Degenerative Pediatric Stress-Induced Epileptic Ataxia Syndrome.}, journal = {Am J Hum Genet}, volume = {103}, year = {2018}, month = {2018 09 06}, pages = {431-439}, abstract = {

ADP-ribosylation, the addition of poly-ADP ribose (PAR) onto proteins, is a response signal to cellular challenges, such as excitotoxicity or oxidative stress. This process is catalyzed by a group of enzymes referred to as poly(ADP-ribose) polymerases (PARPs). Because the accumulation of proteins with this modification results in cell death, its negative regulation restores cellular homeostasis: a process mediated by poly-ADP ribose glycohydrolases (PARGs) and ADP-ribosylhydrolase proteins (ARHs). Using linkage analysis and exome or genome sequencing, we identified recessive inactivating mutations in ADPRHL2 in six families. Affected individuals exhibited a pediatric-onset neurodegenerative disorder with progressive brain atrophy, developmental regression, and seizures in association with periods of stress, such as infections. Loss of the Drosophila paralog Parg showed lethality in response to oxidative challenge that was rescued by human ADPRHL2, suggesting functional conservation. Pharmacological inhibition of PARP also rescued the phenotype, suggesting the possibility of postnatal treatment for this genetic condition.

}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2018.07.010}, author = {Ghosh, Shereen G and Becker, Kerstin and Huang, He and Dixon-Salazar, Tracy and Chai, Guoliang and Salpietro, Vincenzo and Al-Gazali, Lihadh and Waisfisz, Quinten and Wang, Haicui and Vaux, Keith K and Stanley, Valentina and Manole, Andreea and Akpulat, Ugur and Weiss, Marjan M and Efthymiou, Stephanie and Hanna, Michael G and Minetti, Carlo and Striano, Pasquale and Pisciotta, Livia and De Grandis, Elisa and Altm{\"u}ller, Janine and N{\"u}rnberg, Peter and Thiele, Holger and Yis, Uluc and Okur, Tuncay Derya and Polat, Ayse Ipek and Amiri, Nafise and Doosti, Mohammad and Karimani, Ehsan Ghayoor and Toosi, Mehran B and Haddad, Gabriel and Karakaya, Mert and Wirth, Brunhilde and van Hagen, Johanna M and Wolf, Nicole I and Maroofian, Reza and Houlden, Henry and Cirak, Sebahattin and Gleeson, Joseph G} } @article {448, title = {SLC13A5 is the second gene associated with Kohlsch{\"u}tter-T{\"o}nz syndrome.}, journal = {J Med Genet}, volume = {54}, year = {2017}, month = {2017 01}, pages = {54-62}, abstract = {

BACKGROUND: Kohlsch{\"u}tter-T{\"o}nz syndrome (KTZS) is a rare autosomal-recessive disease characterised by epileptic encephalopathy, intellectual disability and amelogenesis imperfecta (AI). It is frequently caused by biallelic mutations in ROGDI. Here, we report on individuals with ROGDI-negative KTZS carrying biallelic SLC13A5 mutations.

METHODS: In the present cohort study, nine individuals from four families with the clinical diagnosis of KTZS and absence of ROGDI mutations as well as one patient with unexplained epileptic encephalopathy were investigated by clinical and dental evaluation, parametric linkage analysis (one family), and exome and/or Sanger sequencing. Dental histological investigations were performed on teeth from individuals with SLC13A5-associated and ROGDI-associated KTZS.

RESULTS: Biallelic mutations in SLC13A5 were identified in 10 affected individuals. Epileptic encephalopathy usually presents in the neonatal and (less frequently) early infantile period. Yellowish to orange discolouration of both deciduous and permanent teeth, as well as wide interdental spaces and abnormal crown forms are major clinical signs of individuals with biallelic SLC13A5 mutations. Histological dental investigations confirmed the clinical diagnosis of hypoplastic AI. In comparison, the histological evaluation of a molar assessed from an individual with ROGDI-associated KTZS revealed hypocalcified AI.

CONCLUSIONS: We conclude that SLC13A5 is the second major gene associated with the clinical diagnosis of KTZS, characterised by neonatal epileptic encephalopathy and hypoplastic AI. Careful clinical and dental delineation provides clues whether ROGDI or SLC13A5 is the causative gene. Hypersensitivity of teeth as well as high caries risk requires individual dental prophylaxis and attentive dental management.

}, keywords = {Alleles, Amelogenesis Imperfecta, Brain Diseases, Cohort Studies, Dementia, Epilepsy, Exome, Female, Genetic Linkage, Genetic Predisposition to Disease, Humans, Male, Membrane Proteins, Mutation, Nuclear Proteins, Pedigree, Symporters, Tooth}, issn = {1468-6244}, doi = {10.1136/jmedgenet-2016-103988}, author = {Schossig, Anna and Bloch-Zupan, Agn{\`e}s and Lussi, Adrian and Wolf, Nicole I and Raskin, Salmo and Cohen, Monika and Giuliano, Fabienne and Jurgens, Julie and Krabichler, Birgit and Koolen, David A and de Macena Sobreira, Nara Lygia and Maurer, Elisabeth and Muller-Bolla, Mich{\`e}le and Penzien, Johann and Zschocke, Johannes and Kapferer-Seebacher, Ines} } @article {51, title = {Loss-of-Function Mutations in FRRS1L Lead to an Epileptic-Dyskinetic Encephalopathy.}, journal = {Am J Hum Genet}, volume = {98}, year = {2016}, month = {2016 06 02}, pages = {1249-1255}, abstract = {

Glutamatergic neurotransmission governs excitatory signaling in the mammalian brain, and abnormalities of glutamate signaling have been shown to contribute to both epilepsy and hyperkinetic movement disorders. The etiology of many severe childhood movement disorders and epilepsies remains uncharacterized. We describe a neurological disorder with epilepsy and prominent choreoathetosis caused by biallelic pathogenic variants in FRRS1L, which encodes an AMPA receptor outer-core protein. Loss of FRRS1L function attenuates AMPA-mediated currents, implicating chronic abnormalities of glutamatergic neurotransmission in this monogenic neurological disease of childhood.

}, keywords = {alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid, Brain Diseases, Electrophysiology, Epilepsy, Female, Humans, Hyperkinesis, Infant, Male, Membrane Proteins, Mutation, Nerve Tissue Proteins, Pedigree, Synaptic Transmission}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2016.04.008}, author = {Madeo, Marianna and Stewart, Michelle and Sun, Yuyang and Sahir, Nadia and Wiethoff, Sarah and Chandrasekar, Indra and Yarrow, Anna and Rosenfeld, Jill A and Yang, Yaping and Cordeiro, Dawn and McCormick, Elizabeth M and Muraresku, Colleen C and Jepperson, Tyler N and McBeth, Lauren J and Seidahmed, Mohammed Zain and El Khashab, Heba Y and Hamad, Muddathir and Azzedine, Hamid and Clark, Karl and Corrochano, Silvia and Wells, Sara and Elting, Mariet W and Weiss, Marjan M and Burn, Sabrina and Myers, Angela and Landsverk, Megan and Crotwell, Patricia L and Waisfisz, Quinten and Wolf, Nicole I and Nolan, Patrick M and Padilla-Lopez, Sergio and Houlden, Henry and Lifton, Richard and Mane, Shrikant and Singh, Brij B and Falk, Marni J and Mercimek-Mahmutoglu, Saadet and Bilguvar, Kaya and Salih, Mustafa A and Acevedo-Arozena, Abraham and Kruer, Michael C} }