rs7966230, also known as -1793G/C, is a SNP in the VWF gene on chromosome 12.
This SNP is reasonably polymorphic in many populations. It does show a significant association with plasma VWF levels, reportedly more marked in subjects who are more than 40 years of age. The variant is reported to be associated with somewhat lower plasma levels of VWF. [PMID 10848823]
Publications discussing this mutation's discovery usually refer to the strand sequenced, since this is a SNP found upstream of the gene in the promoter region. The gene is transcribed in minus direction (based on the GRCh37 assembly), and so on the minus strand, the more common allele is (G) and the variant is (C). However, dbSNP defines this SNP on the plus strand (as does SNPedia and 23andMe), so the more common allele for rs7966230 is reported here as (C) and the variant as (G).
[PMID 23114148] [A1381T and -1793G/C Polymorphisms of vWF Gene Impact the Plasma vWF Levels in Yugur, Tibetan and Han Nationalities of China]