{{Rsnum
|rsid=2491397
|Gene=GABBR2
|Chromosome=9
|position=98442880
|Orientation=plus
|GMAF=0.3893
|Assembly=GRCh38
|GenomeBuild=38.1
|dbSNPBuild=141
|geno1=(C;C)
|geno2=(C;T)
|geno3=(T;T)
|Gene_s=GABBR2
}}{{ population diversity
| geno1=(C;C)
| geno2=(C;T)
| geno3=(T;T)
| CEU | 22.3 | 49.1 | 28.6
| HCB | 69.9 | 27.9 | 2.2
| JPT | 77.9 | 21.2 | 0.9
| YRI | 35.4 | 44.2 | 20.4
| ASW | 38.6 | 42.1 | 19.3
| CHB | 69.9 | 27.9 | 2.2
| CHD | 76.9 | 21.3 | 1.9
| GIH | 25.7 | 39.6 | 34.7
| LWK | 27.5 | 56.9 | 15.6
| MEX | 50.0 | 37.9 | 12.1
| MKK | 20.0 | 49.0 | 31.0
| TSI | 22.5 | 53.9 | 23.5
| HapMapRevision=28
}}{{PMID|15759211|OA=1
}} Associated with [[nicotine Dependence]] as part of several haplotypes, based on a study of 1,000+ subjects including both African-Americans and European-Americans.

The risk haplotype varies between populations. Among African-Americans, the haplotype C-C-G of [[rs2491397]]-[[rs2184026]]-[[rs3750344]] had a significant positive association with [[nicotine dependence]]. Among European-Americans, for [[rs1435252]]-[[rs3780422]]-[[rs2779562]]-[[rs3750344]], the C-A-C-A haplotype was positively associated with [[nicotine dependence]] while the T-A-T-A haplotype was negatively associated.{{PMID|15759211|OA=1
}}

{{omim
|id=607340
|desc=GAMMA-AMINOBUTYRIC ACID B RECEPTOR 2; GABBR2
|rsnum=2491397
}}

{{omim
|id=607340
|rsnum=2491397
|variant=0001
}}

{{on chip | 23andMe v1}}
{{on chip | 23andMe v2}}
{{on chip | 23andMe v3}}
{{on chip | 23andMe v4}}
{{on chip | FTDNA2}}
{{on chip | HumanOmni1Quad}}
{{on chip | Illumina Human 1M}}