|| Homozygous for CYP2D6*52 variant.
|| Carrier of one CYP2D6*52 variant.
|| Homozygous for non-functioning CYP2D6*4H variant.
|| Carrier of one CYP2D6*4H non-functioning variant.
The wild type allele for this SNP is (G) in minus orientation. When it changes to (C) it is known as 3877G>C and is a marker for non-functioning variant CYP2D6*4H.
When it changes to (A) it is known as 3877G>A and is a marker for variant CYP2D6*52 which is possibly a decreased functioning variant, though more study is needed.[PMID 19364831]
Please note that this is in minus orientation and the 3877G>C version is subject to ambiguous flip.