Expressive

rs1123991 (OR51E2): OR51E1 eQTL in muscle and heart

Key takeaways

  • rs1123991 sits in olfactory receptor gene OR51E2 but affects expression of neighboring gene OR51E1 in muscle, heart, and fat tissue
  • The ALT allele consistently increases OR51E1 expression across six tissues in GTEx data from 953 donors
  • The strongest effect is seen in pituitary tissue (slope +0.31), followed by esophageal muscle (+0.25)
  • Evidence is limited to gene-expression data, with no direct clinical outcome associations established from the provided studies

Key takeaways

  • rs1123991 sits in OR51E2, an olfactory receptor gene, and acts as an eQTL (a genetic variant influencing how much a nearby gene is switched on) for the neighboring gene OR51E1 across multiple tissues.
  • The ALT allele of this variant is consistently linked to increased OR51E1 expression in six tissues: pituitary, esophageal muscle, skeletal muscle, heart left ventricle, visceral fat, and subcutaneous fat.
  • The strongest expression effect is observed in the pituitary gland, followed by esophageal muscularis.
  • Evidence for this variant comes primarily from tissue-specific gene-expression data in GTEx v11 (953 donors), and direct clinical outcome data from the provided studies is not available.
  • No lifestyle considerations are currently on file for this variant.

What the research says A genome-wide association study (GWAS, a large-scale scan across the genome for variants linked to traits) of 490 elite athletes profiling 275,016 genetic variants alongside 751 serum metabolites investigated metabolic quantitative trait loci (genetic variants associated with measurable metabolite levels) relevant to athletic performance; the available study text does not report specific findings for rs1123991 in this context. Gene-expression analysis from GTEx v11, a reference dataset covering 953 donors across many tissue types, shows that the ALT allele at rs1123991 is associated with increased expression of OR51E1 (a neighboring olfactory receptor gene) across six distinct body tissues, with all associations meeting a false discovery rate (FDR, a statistical threshold limiting false positives) of less than 0.05 GTEx Portal. Effect sizes (log2-normalized slopes, a measure of expression change per ALT allele copy) range from +0.18 in subcutaneous fat to +0.31 in pituitary, all in the direction of increased expression GTEx Portal.

Reported associations

  • OR51E1 expression, pituitary: the ALT allele is associated with increased OR51E1 expression in pituitary tissue (slope +0.31, p=1.5e-6) GTEx Portal
  • OR51E1 expression, esophagus muscularis: the ALT allele is associated with increased OR51E1 expression in esophageal smooth muscle (slope +0.25, p=1.2e-5) GTEx Portal
  • OR51E1 expression, skeletal muscle: the ALT allele is associated with increased OR51E1 expression in skeletal muscle (slope +0.20, p=1.6e-5) GTEx Portal
  • OR51E1 expression, heart left ventricle: the ALT allele is associated with increased OR51E1 expression in the left pumping chamber of the heart (slope +0.19, p=3.0e-5) GTEx Portal
  • OR51E1 expression, visceral adipose: the ALT allele is associated with increased OR51E1 expression in visceral fat (deep abdominal fat surrounding internal organs) (slope +0.19, p=2.5e-6) GTEx Portal
  • OR51E1 expression, subcutaneous adipose: the ALT allele is associated with increased OR51E1 expression in subcutaneous fat (fat stored directly under the skin) (slope +0.18, p=2.7e-5) GTEx Portal

Evidence quality All eQTL associations are from GTEx v11, based on 953 donors with a cis-window approach (testing variants within a short genomic distance of the target gene) and an FDR threshold below 0.05 GTEx Portal. Effect sizes are modest and entirely consistent in direction across all six tissues, with no conflicting signals present in the provided data. A separate GWAS of 490 elite athletes examining 275,016 SNPs and 751 serum metabolites provides methodological context for genomic research in performance-related traits, but the available study text does not name rs1123991 among its reported loci. The overall evidence base for this variant is therefore narrow, resting on gene-expression associations rather than clinical or disease-outcome data, and all findings should be treated as preliminary.

Tissue-specific expression effects

  • OR51E1: the ALT allele is associated with increased expression in six tissues (pituitary, strongest effect; esophagus muscularis; skeletal muscle; heart left ventricle; visceral adipose; subcutaneous adipose), with all signals meeting FDR less than 0.05 in GTEx v11 from 953 donors GTEx Portal

Lifestyle considerations No lifestyle considerations on file for this variant.

Frequently asked questions

What is rs1123991?

rs1123991 is a genetic variant located in OR51E2, a gene in the olfactory receptor family. Based on GTEx gene-expression data from 953 donors, the ALT allele of this variant is associated with increased expression of a neighboring gene, OR51E1, in multiple tissues including muscle, heart, and fat.

What does OR51E2 do?

OR51E2 belongs to the olfactory receptor gene family, a large group of genes encoding proteins involved in detecting smells. GTEx data indicates that variants in this region also influence expression of the neighboring gene OR51E1 in non-olfactory tissues such as muscle, heart, and fat.

Which tissues does rs1123991 affect?

GTEx v11 data from 953 donors shows that the ALT allele of rs1123991 is linked to increased OR51E1 expression in six tissues: pituitary, esophagus muscularis, skeletal muscle, heart left ventricle, visceral adipose (belly fat), and subcutaneous adipose (under-skin fat).

Is rs1123991 linked to athletic performance?

A GWAS study of 490 elite athletes examined metabolic variants relevant to athletic performance, but the available text from that study does not explicitly report findings specific to rs1123991.

What is an eQTL?

An eQTL (expression quantitative trait locus) is a genetic variant that influences how much a specific gene is expressed, or switched on, in a given tissue. eQTL effects describe a potential molecular mechanism but do not by themselves predict disease risk or health outcomes.