rs7900194, also known as 449G>A, 3627G>A or R150H, is a SNP in the CYP2C9 gene.
The rs7900194(A) allele defines the CYP2C9*8 variant, which has decreased activity.
According to a 23andMe discussion This is one of the SNPs which were re-analyzed April 2009. Customers with older data may wish to redownload. SNPs effected rs4420638, rs34276300, rs3091244, rs34601266, rs2033003, rs7900194, rs9332239, rs28371685, rs1229984, and rs28399504.
[PMID 19663669] CYP2C9*8 is prevalent among African-Americans: implications for pharmacogenetic dosing.