title: The genetic aetiology of cannabis use initiation: a meta-analysis of genome-wide association studies and a SNP-based heritability estimation.
abstract: While initiation of cannabis use is around 40% heritable, not much is known about the underlying genetic aetiology. Here, we meta-analysed two genome-wide association studies of initiation of cannabis use with > 10 000 individuals. None of the genetic variants reached genome-wide significance. We also performed a gene-based association test, which also revealed no significant effects of individual genes. Finally, we estimated that only approximately 6% of the variation in cannabis initiation is due to common genetic variants. Future genetic studies using larger sample sizes and different methodologies (including sequencing) might provide more insight in the complex genetic aetiology of cannabis use.
authors: Queensland Institute of Medical Research, Australia. karin.verweij@qimr.edu.au
authors: Karin J H
authors: KJ
authors: Verweij
authors: Anna A E
authors: AA
authors: Vinkhuyzen
authors: Beben
authors: B
authors: Benyamin
authors: Michael T
authors: MT
authors: Lynskey
authors: Lydia
authors: L
authors: Quaye
authors: Arpana
authors: A
authors: Agrawal
authors: Scott D
authors: SD
authors: Gordon
authors: Grant W
authors: GW
authors: Montgomery
authors: Pamela A F
authors: PA
authors: Madden
authors: Andrew C
authors: AC
authors: Heath
authors: Timothy D
authors: TD
authors: Spector
authors: Nicholas G
authors: NG
authors: Martin
authors: Sarah E
authors: SE
authors: Medland
mesh_terms: D000328:Adult; D001315:Australia / Q000453:epidemiology; D005260:Female; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D055106:Genome-Wide Association Study; D005838:Genotype; D006801:Humans; D008297:Male; D002189:Marijuana Abuse / Q000453:epidemiology / Q000235:genetics*; D008875:Middle Aged; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D018433:Twin Studies as Topic; D006113:United Kingdom / Q000453:epidemiology