{{Rsnum
|rsid=55640102
|Orientation=plus
|ReferenceAllele=A
|MissenseAllele=C
|geno1=(A;A)
|geno2=(A;C)
|geno3=(C;C)
|Chromosome=10
|position=96612671
|Gene=CYP2C19
|Assembly=GRCh37
|GenomeBuild=37.1
|dbSNPBuild=131
}}The [[rs55640102]](C) SNP defines the [[CYP2C19]] allele known as CYP2C19*12, also known as X491C.

{{on chip | 23andMe v3}}
{{on chip | 23andMe v4}}