rs41303343

A SNP in the CYP3A5 gene on chromosome 7. Its most notable genotype is A;A: Miscall in 23andMe v4 data; otherwise, CYP3A5*7 homozygote; nonexpressor for CYP3A5

Gene
CYP3A5
Location
Chr 799,652,770 (GRCh38)
Highest magnitude
2.5Worth knowing
Tested on
23andMe, AncestryDNA
Minor allele frequency
3%

Genotypes

Plus strand, as in 23andMe and AncestryDNA files.

  1. -;-GoodnormalTypical · 0.0
  2. -;ANot ratedcarrier of one CYP3A5*7 alleleWorth knowing · 2.0
  3. A;AMost notableBadMiscall in 23andMe v4 data; otherwise, CYP3A5*7 homozygote; nonexpressor for CYP3A5Worth knowing · 2.5

SNPedia records rs41303343 on the minus strand: (-;-), (-;T), (T;T). Magnitude rates how notable a genotype is from 0 to 10, not how risky it is.

Other CYP3A5 SNPs

All CYP3A5 SNPs

Genosets

Genosets combine several genotypes. Twofold checks them in your report.

Notes

From SNPedia

Show notes, about 150 words

rs41303343, also known as 27131_27132insT, is a SNP in the CYP3A5 gene. The rs41303343(T) allele defines the CYP3A5*7 variant, which is nonfunctional and has the highest prevalence in those of African descent (where ~8% of the population are carriers). Note that the scientific literature (and PharmGKB, among other sources) often incorrectly reports a different SNP (rs76293380) as defining the CYP3A5*7 allele. That SNP is actually defined as a deletion, not as in insertion, at the same position as rs41303343. In 23andMe v4-based data, this SNP is reported nearly 100% of the time as II (which would be equivalent to TT), and this is clearly incorrect. In 23andMe v5-based data, this SNP is normally missing.

A;A

If this is based on 23andMe data, it's highly likely to be a miscall. If this is based on data from another company, it's more likely to be real, but statistically it's only likely in people of African descent.

Source and license

Adapted from rs41303343 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 Its entries can be incomplete, out of date or wrong, and nothing here is a diagnosis or medical advice.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.