rs366631

A SNP in the GSTM5 gene on chromosome 1. Its most notable genotype is G;G: GSTM1*1 status

Gene
GSTM5
Location
Chr 1109,709,850 (GRCh38)
Highest magnitude
1.3Minor
Tested on
23andMe

Genotypes

Plus strand, as in 23andMe and AncestryDNA files.

  1. G;GMost notableGoodGSTM1*1 statusMinor · 1.36% of people
  2. A;GGoodGSTM1*1 statusMinor · 1.344% of people
  3. A;ABadCommon in Caucasians; GSTM1*0/0 null statusMinor · 1.350% of people

SNPedia records rs366631 on the minus strand: (C;C), (C;T), (T;T). Magnitude rates how notable a genotype is from 0 to 10, not how risky it is.

Frequency

Share of each genotype in 4 HapMap populations.

  • AverageG;G 6% A;G 44% A;A 50%
  • European ancestry (Utah)G;G 0% A;G 33% A;A 67%
  • Han Chinese (Beijing)G;G 0% A;G 50% A;A 50%
  • Japanese (Tokyo)G;G 0% A;G 40% A;A 61%
  • Yoruba (Nigeria)G;G 22% A;G 54% A;A 24%

Conditions, medicines and genes

Notes

From SNPedia

Show notes, about 180 words

Although located 11kb away from it, rs366631 is effectively a pseudo-SNP tagging the status of the GSTM1 gene, due to the nature of the duplications and deletions in this part of chromosome 1. In typical microarray-based genotyping results, the correspondence between the rs366631 call and GSTM1 allele status is the following: * rs366631(T;T): GSTM1*0/0, i.e. GSTM null allele (double deletion) * rs366631 (C;T) and (C;C): GSTM1*1, i.e. at least one functional GSTM1 gene copy is present The GSTM1*0/0 null phenotype has a frequency of greater than 50% among Caucasian, Chinese, and Indian populations, and sporadic reports over the years (many based on rather small sample sizes) indicate that it may be a slight risk factor for certain cancers based on increased sensitivity to particular chemical carcinogens. Identification of genetic variants and gene expression relationships associated with pharmacogenes in humans. Population-specific GSTM1 copy number variation.

G;G

see discussion at rs366631

A;G

see discussion at rs366631

A;A

see discussion at rs366631

Source and license

Adapted from rs366631 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 Its entries can be incomplete, out of date or wrong, and nothing here is a diagnosis or medical advice.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.