1 Scientific RepoRts | 6:31033 | DOI: 10.1038/srep31033 www.nature.com/scientificreports A Highly polymorphic Copy Number Variant in the NSF Gene is Associated with Cocaine Dependence Judit Cabana-Domínguez 1,2,3,4 , Carlos Roncero 5,6,7,8 , Lara Grau-López 5,6,7,8 , Laia Rodríguez-Cintas 6,7 , Carmen Barral 5,6,7,8 , Alfonso C. Abad 5,6 , Galina erikson 9 , Nathan e. Wineinger 9 , Bàrbara torrico 1,2,3,4 , Concepció Arenas 1 , Miquel Casas 5,7,8 , Marta Ribasés 5,8,10 , Bru Cormand 1,2,3,4,* & Noèlia Fernàndez-Castillo 1,2,3,4,* Cocaine dependence is a complex psychiatric disorder involving both genetic and environmental factors. Several neurotransmitter systems mediate cocaine’s efects, dependence and relapse, being the components of the neurotransmitter release machinery good candidates for the disorder. Previously, we identifed a risk haplotype for cocaine dependence in the NSF gene, encoding the protein N-ethylmaleimide-sensitive Factor essential for synaptic vesicle turnover. Here we examined the possible contribution to cocaine dependence of a large copy number variant (CNV) that encompasses part of the NSF gene. We performed a case-control association study in a discovery sample (359 cases and 356 controls) and identifed an association between cocaine dependence and the CNV (P = 0.013), that was confrmed in the replication sample (508 cases and 569 controls, P = 7.1e-03) and in a pooled analysis (P = 1.8e-04), with an over-representation of low number of copies in cases. Subsequently, we studied the functional impact of the CNV on gene expression and found that the levels of two NSF transcripts were signifcantly increased in peripheral blood mononuclear cells (PBMC) along with the number of copies of the CNV. these results, together with a previous study from our group, support the role of NSF in the susceptibility to cocaine dependence. Cocaine dependence is a complex psychiatric disorder that results from the interaction between genetic and envi- ronmental factors, with an estimated heritability of 65–79% 1–3 . Cocaine inhibits dopamine, serotonin and norep- inephrine reuptake by binding to their transporters (DAT1, SERT and NET, respectively), increasing their levels at the synaptic clef 4,5 . Also, other neurotransmitter pathways participate in cocaine dependence, withdrawal or relapse, including the glutamatergic, GABAergic and endocannabinoid systems 6–12 . Teir involvement in medi- ating cocaine efects and dependence makes the molecular machinery that controls neurotransmitter release to the synaptic clef a strong candidate for participating in the development of cocaine dependence. As part of this complex process that involves many diferent proteins, the N-ethylmaleimide sensitive factor (NSF) plays an essential role in the synaptic vesicle turnover. NSF is responsible for the recycling of Soluble NSF Attachment 1 Departament de Genètica, Microbiologia i estadística, facultat de Biologia, Universitat de Barcelona, Barcelona, catalonia, Spain. 2 centro de investigación Biomédica en Red de enfermedades Raras (ciBeReR), instituto de Salud carlos iii, Spain. 3 institut de Biomedicina de la Universitat de Barcelona (iBUB), Barcelona, catalonia, Spain. 4 institut de Recerca Pediàtrica Hospital Sant Joan de Déu, esplugues, Barcelona, catalonia, Spain. 5 Department of Psychiatry, Hospital Universitari Vall d’Hebron, Barcelona, catalonia, Spain. 6 Addiction and Dual Diagnosis Unit clinic Vall Hebron, Psychiatric Services, Hospital Universitari Vall d’Hebron-ASPB, Barcelona, catalonia, Spain. 7 Psychiatric Department and Legal Medicine. Universitat Autònoma de Barcelona, catalonia, Spain. 8 centro de investigación Biomédica en Red de Salud Mental (ciBeRSAM), instituto de Salud carlos iii, Spain. 9 Scripps translational Science institute, La Jolla, cA, United States of America. 10 Psychiatric Genetics Unit, Hospital Universitari Vall d’Hebron, Universitat Autònoma de Barcelona, Barcelona, catalonia, Spain. * these authors contributed equally to this work. correspondence and requests for materials should be addressed to B.c. (email: bcormand@ub.edu) or n.f.-c. (email: noefernandez@ub.edu) Received: 08 April 2016 Accepted: 12 July 2016 Published: 08 August 2016 opeN