rs1135840
A SNP in the LOC102723722 gene on chromosome 22. Its most notable genotype is G;G: Homozygous for CYP2D6 variants (non-CYP2D6*1)
- Gene
- LOC102723722
- Location
- Chr 2242,126,611 (GRCh38)
- Highest magnitude
- 2.0Worth knowing
- Tested on
- 23andMe, AncestryDNA
- Minor allele frequency
- 40%
Genotypes
Plus strand, as in 23andMe and AncestryDNA files.
- G;GMost notableNot ratedHomozygous for CYP2D6 variants (non-CYP2D6*1)
- C;GNot ratedCarrier of at least one CYP2D6 variant (non-CYP2D6*1)
- C;CGoodnormal
SNPedia records rs1135840 on the minus strand: (C;C), (C;G), (G;G). Magnitude rates how notable a genotype is from 0 to 10, not how risky it is.
Related
Conditions, medicines and genes
Other LOC102723722 SNPs
- rs1135824C;CTwo copies of CYP2D6*3B non-functioning variantVery important
- rs5030867G;GCYP2D6*7 homozygoteVery important
- rs1065852A;AHomozygous for CYP2D6 decreased or non-functioning variants; possibly less response to some drugs, including tamoxifenImportant
- rs3892097T;TCYP2D6 poor metabolizer; many associations related to drug metabolismImportant
- rs5030655-;-CYP2D6*6 poor metabolizer phenotypeImportant
- rs28371733G;GHomozygous for non-functioning CYP2D6*4H variant.Important
- rs72549354C;CTwo CYP2D6*20 alleles; significantly lowered metabolism of certain drugsImportant
- rs5030656-;-CYP2D6*9 homozygoteWorth knowing
Genosets
Genosets combine several genotypes. Twofold checks them in your report.
Notes
From SNPedia
Show notes, about 130 words
rs1135840, also known as 4180G>C or S486T, is a SNP in the CYP2D6 gene. The wild type (normal) allele at this SNP is (G). The (C) variant indicates the presence of a non-wild type CYP2D6 variant, but it appears in many different variants so it can not be used to determine the presence of any particular variant. Please be careful when interpreting results for this SNP as it is in dbSNP and SNPedia in minus orientation where the risk allele is C, but test results are usually in plus orientation where the risk allele is G. This SNP has an ambiguous flip which can make this very confusing. Polymorphisms affecting gene transcription and mRNA processing in pharmacogenetic candidate genes: detection through allelic expression imbalance in human target tissues.
Source and license
Adapted from rs1135840 on SNPedia, using a snapshot taken October 16, 2026. SNPedia content is shared under CC BY-NC-SA 3.0 US, and this page is shared under the same license.
SNPedia is a community-edited wiki. Its entries can be incomplete, out of date or wrong, and nothing here is a diagnosis or medical advice. Magnitude is a community rating of how interesting a genotype is, not a risk score.