@article {846, title = {Genetic diagnoses in epilepsy: The impact of dynamic exome analysis in a pediatric cohort.}, journal = {Epilepsia}, volume = {61}, year = {2020}, month = {2020 02}, pages = {249-258}, abstract = {

OBJECTIVE: We evaluated the yield of systematic analysis and/or reanalysis of whole exome sequencing (WES) data from a cohort of well-phenotyped pediatric patients with epilepsy and suspected but previously undetermined genetic etiology.

METHODS: We identified and phenotyped 125 participants with pediatric epilepsy. Etiology was unexplained at the time of enrollment despite clinical testing, which included chromosomal microarray (57 patients), epilepsy gene panel (n = 48), both (n = 28), or WES (n = 8). Clinical epilepsy diagnoses included developmental and epileptic encephalopathy (DEE), febrile infection-related epilepsy syndrome, Rasmussen encephalitis, and other focal and generalized epilepsies. We analyzed WES data and compared the yield in participants with and without prior clinical genetic testing.

RESULTS: Overall, we identified pathogenic or likely pathogenic variants in 40\% (50/125) of our study participants. Nine patients with DEE had genetic variants in recently published genes that had not been recognized as epilepsy-related at the time of clinical testing (FGF12, GABBR1, GABBR2, ITPA, KAT6A, PTPN23, RHOBTB2, SATB2), and eight patients had genetic variants in candidate epilepsy genes (CAMTA1, FAT3, GABRA6, HUWE1, PTCHD1). Ninety participants had concomitant or subsequent clinical genetic testing, which was ultimately explanatory for 26\% (23/90). Of the 67 participants whose molecular diagnoses were "unsolved" through clinical genetic testing, we identified pathogenic or likely pathogenic variants in 17 (25\%).

SIGNIFICANCE: Our data argue for early consideration of WES with iterative reanalysis for patients with epilepsy, particularly those with DEE or epilepsy with intellectual disability. Rigorous analysis of WES data of well-phenotyped patients with epilepsy leads to a broader understanding of gene-specific phenotypic spectra as well as candidate disease gene identification. We illustrate the dynamic nature of genetic diagnosis over time, with analysis and in some cases reanalysis of exome data leading to the identification of disease-associated variants among participants with previously nondiagnostic results from a variety of clinical testing strategies.

}, keywords = {Adolescent, Adult, Age of Onset, Brain Diseases, Child, Child, Preschool, Chromosomes, Human, Cohort Studies, Epilepsy, Epilepsy, Generalized, Exome, Female, Genetic Testing, Genetic Variation, Humans, Infant, Male, Microarray Analysis, Phenotype, Whole Exome Sequencing, Young Adult}, issn = {1528-1167}, doi = {10.1111/epi.16427}, author = {Rochtus, Anne and Olson, Heather E and Smith, Lacey and Keith, Louisa G and El Achkar, Christelle and Taylor, Alan and Mahida, Sonal and Park, Meredith and Kelly, McKenna and Shain, Catherine and Rockowitz, Shira and Rosen Sheidley, Beth and Poduri, Annapurna} } @article {589, title = {Missense Variants in the Histone Acetyltransferase Complex Component Gene TRRAP Cause Autism and Syndromic Intellectual Disability.}, journal = {Am J Hum Genet}, volume = {104}, year = {2019}, month = {2019 03 07}, pages = {530-541}, abstract = {

Acetylation of the lysine residues in histones and other DNA-binding proteins plays a major role in regulation of eukaryotic gene expression. This process is controlled by histone acetyltransferases (HATs/KATs) found in multiprotein complexes that are recruited to chromatin by the scaffolding subunit transformation/transcription domain-associated protein (TRRAP). TRRAP is evolutionarily conserved and is among the top five genes intolerant to missense variation. Through an international collaboration, 17 distinct de novo or apparently de novo variants were identified in TRRAP in 24 individuals. A strong genotype-phenotype correlation was observed with two distinct clinical spectra. The first is a complex, multi-systemic syndrome associated with various malformations of the brain, heart, kidneys, and genitourinary system and characterized by a wide range of intellectual functioning; a number of affected individuals have intellectual disability (ID) and markedly impaired basic life functions. Individuals with this phenotype had missense variants clustering around the c.3127G>A p.(Ala1043Thr) variant identified in five individuals. The second spectrum manifested with autism spectrum disorder (ASD) and/or ID and epilepsy. Facial dysmorphism was seen in both groups and included upslanted palpebral fissures, epicanthus, telecanthus, a wide nasal bridge and ridge, a broad and smooth philtrum, and a thin upper lip. RNA sequencing analysis of skin fibroblasts derived from affected individuals skin fibroblasts showed significant changes in the expression of several genes implicated in neuronal function and ion transport. Thus, we describe here the clinical spectrum associated with TRRAP pathogenic missense variants, and we suggest a genotype-phenotype correlation useful for clinical evaluation of the pathogenicity of the variants.

}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2019.01.010}, author = {Cogn{\'e}, Benjamin and Ehresmann, Sophie and Beauregard-Lacroix, Eliane and Rousseau, Justine and Besnard, Thomas and Garcia, Thomas and Petrovski, Slav{\'e} and Avni, Shiri and McWalter, Kirsty and Blackburn, Patrick R and Sanders, Stephan J and Uguen, K{\'e}vin and Harris, Jacqueline and Cohen, Julie S and Blyth, Moira and Lehman, Anna and Berg, Jonathan and Li, Mindy H and Kini, Usha and Joss, Shelagh and von der Lippe, Charlotte and Gordon, Christopher T and Humberson, Jennifer B and Robak, Laurie and Scott, Daryl A and Sutton, Vernon R and Skraban, Cara M and Johnston, Jennifer J and Poduri, Annapurna and Nordenskj{\"o}ld, Magnus and Shashi, Vandana and Gerkes, Erica H and Bongers, Ernie M H F and Gilissen, Christian and Zarate, Yuri A and Kvarnung, Malin and Lally, Kevin P and Kulch, Peggy A and Daniels, Brina and Hernandez-Garcia, Andres and Stong, Nicholas and McGaughran, Julie and Retterer, Kyle and Tveten, Kristian and Sullivan, Jennifer and Geisheker, Madeleine R and Stray-Pedersen, Asbjorg and Tarpinian, Jennifer M and Klee, Eric W and Sapp, Julie C and Zyskind, Jacob and Holla, {\O}ystein L and Bedoukian, Emma and Filippini, Francesca and Guimier, Anne and Picard, Arnaud and Busk, {\O}yvind L and Punetha, Jaya and Pfundt, Rolph and Lindstrand, Anna and Nordgren, Ann and Kalb, Fayth and Desai, Megha and Ebanks, Ashley Harmon and Jhangiani, Shalini N and Dewan, Tammie and Coban Akdemir, Zeynep H and Telegrafi, Aida and Zackai, Elaine H and Begtrup, Amber and Song, Xiaofei and Toutain, Annick and Wentzensen, Ingrid M and Odent, Sylvie and Bonneau, Dominique and Latypova, X{\'e}nia and Deb, Wallid and Redon, Sylvia and Bilan, Fr{\'e}d{\'e}ric and Legendre, Marine and Troyer, Caitlin and Whitlock, Kerri and Caluseriu, Oana and Murphree, Marine I and Pichurin, Pavel N and Agre, Katherine and Gavrilova, Ralitza and Rinne, Tuula and Park, Meredith and Shain, Catherine and Heinzen, Erin L and Xiao, Rui and Amiel, Jeanne and Lyonnet, Stanislas and Isidor, Bertrand and Biesecker, Leslie G and Lowenstein, Dan and Posey, Jennifer E and Denomm{\'e}-Pichon, Anne-Sophie and F{\'e}rec, Claude and Yang, Xiang-Jiao and Rosenfeld, Jill A and Gilbert-Dussardier, Brigitte and Audebert-Bellanger, S{\'e}verine and Redon, Richard and Stessman, Holly A F and Nellaker, Christoffer and Yang, Yaping and Lupski, James R and Goldstein, David B and Eichler, Evan E and Bolduc, Francois and B{\'e}zieau, St{\'e}phane and K{\"u}ry, S{\'e}bastien and Campeau, Philippe M} } @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} }