rs17580

A SNP in the SERPINA1 gene on chromosome 14. Its most notable genotype is A;A: a slightly reduced functionality form of Alpha-1 Antitrypsin Deficiency

Gene
SERPINA1
Location
Chr 1494,380,925 (GRCh38)
Highest magnitude
2.5Worth knowing
Tested on
23andMe, AncestryDNA
Minor allele frequency
3%

Genotypes

Plus strand, as in 23andMe and AncestryDNA files.

  1. T;TGoodcommon in complete genomicsTypical · 0.098% of people
  2. A;TBadCarrier of one PiS variant; slight chance of Alpha-1 Antitrypsin DeficiencyWorth knowing · 2.33% of people
  3. A;AMost notableBada slightly reduced functionality form of Alpha-1 Antitrypsin DeficiencyWorth knowing · 2.50% of people

SNPedia records rs17580 on the minus strand: (A;A), (A;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.

  • AverageT;T 98% A;T 3% A;A 0%
  • European ancestry (Utah)T;T 90% A;T 10% A;A 0%
  • Han Chinese (Beijing)T;T 100% A;T 0% A;A 0%
  • Japanese (Tokyo)T;T 100% A;T 0% A;A 0%
  • Yoruba (Nigeria)T;T 100% A;T 0% A;A 0%

Conditions, medicines and genes

Other SERPINA1 SNPs

All SERPINA1 SNPs

Genosets

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

Notes

From SNPedia

Show notes, about 240 words

rs17580, also known as the S or PiS allele, is a SNP in the SERPINA1 gene. Levels of alpha-1 antitrypsin (encoded by the SERPINA1 gene) may be reduced in carriers of the rs17580(T) allele, but there is no known association with liver disease or cystic fibrosis. The rs17580 PiS variant is most associated with risk of developing COPD, especially in smokers, but it's association with emphysema is variable. See rs28929474 for the most common pathologic SNP (PiZ) in the SERPINA1 gene. Due to orientation, be careful when interpreting results for this SNP which is an ambiguous flip. a relatively small study of 182 patients found no association between rs17580 and risk for cholangiocarcinoma Alpha-1 Antitrypsin Deficiency

A;T

This genotype corresponds to a carrier of one PiS variant for alpha-1-antitrypsin deficiency; individual carrying two PiS variants have 60% of normal enzymatic activity. On its own, carrying one PiS variant has little consequence, however, 3-4% of individuals carrying one PiS variant also carry one copy of the more severe PiZ variant, rs28929474(A), which is associated with an increased risk of emphysema and COPD.

A;A

This variant represents carrying two copies of the PiS variant in alpha-1-antitrypsin deficiency with 60% enzymatic activity. No direct correlation with liver disease according to Liver Disease in Alpha 1-Antitrypsin Deficiency: A Review and no increased risk of emphysema according to omim.org.

Source and license

Adapted from rs17580 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.