TY - JOUR T1 - Heterogeneous contribution of microdeletions in the development of common generalised and focal epilepsies JF - Journal of Medical Genetics JO - J Med Genet SP - 598 LP - 606 DO - 10.1136/jmedgenet-2016-104495 VL - 54 IS - 9 AU - Eduardo Pérez-Palma AU - Ingo Helbig AU - Karl Martin Klein AU - Verneri Anttila AU - Heiko Horn AU - Eva Maria Reinthaler AU - Padhraig Gormley AU - Andrea Ganna AU - Andrea Byrnes AU - Katharina Pernhorst AU - Mohammad R Toliat AU - Elmo Saarentaus AU - Daniel P Howrigan AU - Per Hoffman AU - Juan Francisco Miquel AU - Giancarlo V De Ferrari AU - Peter Nürnberg AU - Holger Lerche AU - Fritz Zimprich AU - Bern A Neubauer AU - Albert J Becker AU - Felix Rosenow AU - Emilio Perucca AU - Federico Zara AU - Yvonne G Weber AU - Dennis Lal Y1 - 2017/09/01 UR - http://jmg.bmj.com/content/54/9/598.abstract N2 - Background Microdeletions are known to confer risk to epilepsy, particularly at genomic rearrangement ‘hotspot’ loci. However, microdeletion burden not overlapping these regions or within different epilepsy subtypes has not been ascertained.Objective To decipher the role of microdeletions outside hotspots loci and risk assessment by epilepsy subtype.Methods We assessed the burden, frequency and genomic content of rare, large microdeletions found in a previously published cohort of 1366 patients with genetic generalised epilepsy (GGE) in addition to two sets of additional unpublished genome-wide microdeletions found in 281 patients with rolandic epilepsy (RE) and 807 patients with adult focal epilepsy (AFE), totalling 2454 cases. Microdeletions were assessed in a combined and subtype-specific approaches against 6746 controls.Results When hotspots are considered, we detected an enrichment of microdeletions in the combined epilepsy analysis (adjusted p=1.06×10−6,OR 1.89, 95% CI 1.51 to 2.35). Epilepsy subtype-specific analyses showed that hotspot microdeletions in the GGE subgroup contribute most of the overall signal (adjusted p=9.79×10−12, OR 7.45, 95% CI 4.20–13.5). Outside hotspots , microdeletions were enriched in the GGE cohort for neurodevelopmental genes (adjusted p=9.13×10−3,OR 2.85, 95% CI 1.62–4.94). No additional signal was observed for RE and AFE. Still, gene-content analysis identified known (NRXN1, RBFOX1 and PCDH7) and novel (LOC102723362) candidate genes across epilepsy subtypes that were not deleted in controls.Conclusions Our results show a heterogeneous effect of recurrent and non-recurrent microdeletions as part of the genetic architecture of GGE and a minor contribution in the aetiology of RE and AFE. ER -