rs55714927 — ASGR1 ASGR1 K89K

ASGR1 K89K — A Common Cholesterol-Protective Variant at the Ashwell Receptor Locus

The liver's job includes clearing old and damaged glycoproteins from the bloodstream. This housekeeping task is performed by the asialoglycoprotein receptor (ASGR)¹¹ asialoglycoprotein receptor (ASGR)
A heteromeric lectin complex on hepatocyte surfaces that binds and internalizes glycoproteins bearing exposed galactose or N-acetylgalactosamine residues — also called the Ashwell-Morell receptor after its discoverers. One of its subunits, encoded by ASGR1 on chromosome 17, turns out to be a key modulator of plasma cholesterol — and a natural human experiment involving both rare loss-of-function mutations and the common variant rs55714927 has revealed why inhibiting this receptor might be one of the next frontiers in lipid-lowering therapy.

rs55714927 is a synonymous coding variant (Lys89Lys, c.267G>A on the coding strand) that acts as a splicing and expression quantitative trait locus (sQTL/eQTL) for ASGR1. Despite not changing the amino acid sequence, it alters ASGR1 mRNA processing, reducing functional receptor output. Carriers of the A allele show lower LDL and non-HDL cholesterol at levels that reach genome-wide significance in large GWAS datasets.

The Mechanism

ASGR1 sits at the top of an unexpected cholesterol-regulatory cascade. When the receptor functions normally, it binds asialoglycoproteins and delivers them to lysosomes for degradation. The resulting flood of amino acids into the lysosomal lumen activates mTORC1²² mTORC1
the mechanistic target of rapamycin complex 1, a central nutrient-sensing kinase that, among many roles, suppresses AMPK — the cellular energy sensor. Active mTORC1 keeps AMPK suppressed; suppressed AMPK fails to stabilize LXRα, the master transcription factor for reverse cholesterol transport. The net result: less cholesterol pumped out to bile via ABCA1, ABCG5, and ABCG8.

Reduce ASGR1 activity — as the A allele at rs55714927 does — and the chain runs in reverse: reduced lysosomal amino-acid flux → mTORC1 inhibition → AMPK activation → LXRα stabilization → upregulation of ABCA1/ABCG5/G8 → more cholesterol excreted to bile and stool. Simultaneously, AMPK suppresses SREBP1, reducing de novo lipogenesis. ASGR1 also acts as a PCSK9-independent ligand for the hepatic LDL receptor³³ PCSK9-independent ligand for the hepatic LDL receptor
ASGR1 interacts with LDLR on the hepatocyte surface; when ASGR1 levels fall, LDLR expression increases, accelerating LDL clearance by a second mechanism. The combined result — more cholesterol exported out, less produced, and more LDL cleared — yields a meaningful reduction in plasma non-HDL and LDL cholesterol.

The Evidence

The mechanism was established mechanistically by Wang et al. in Nature 2022⁴⁴ Wang et al. in Nature 2022
PMID 35922515 — anti-ASGR1 neutralizing antibodies in mice and cells activated the full AMPK→LXRα→ABCA1/ABCG5/G8 axis and synergized with atorvastatin and ezetimibe to produce greater LDL-C lowering than either drug alone.

The human genetic evidence for rs55714927 as a cholesterol-protective locus comes from several converging sources. Sanna et al., Atherosclerosis 2020 (PMID 32679274)⁵⁵ Sanna et al., Atherosclerosis 2020 (PMID 32679274)
Studied three common ASGR1 locus variants (including rs55714927) in UK Biobank, confirming genome-wide significant LDL-C association and testing for CAD and myocardial infarction outcomes demonstrated that the ASGR1 genetic risk score confers a 23% relative risk reduction for CAD per 10 mg/dL LDL-C reduction (OR 0.77, 95% CI 0.62–0.96). Crucially, this risk reduction was proportionally equivalent to that observed for genetic instruments of HMGCR (statins), NPC1L1 (ezetimibe), PCSK9, and LDLR — evidence that the CAD protection is entirely explained by LDL lowering, with no pleiotropic bonus or penalty.

A drug-target Mendelian randomization study BMC Medicine 2023 (PMID 37400795)⁶⁶ BMC Medicine 2023 (PMID 37400795)
Used rs55714927 and rs150688657 as independent genetic instruments to mimic ASGR1 inhibition across 1,951 health-related phenotypes in UK Biobank found that genetically mimicked ASGR1 inhibition was associated with lower apoB and triglycerides — effects stronger than for statin or ezetimibe genetic instruments — along with a 3.31-year gain in lifespan per standard deviation reduction in LDL-C (95% CI 1.01–5.62). The PheWAS also detected mildly elevated liver enzymes (alkaline phosphatase, GGT), increased IGF-1, CRP, and erythrocyte traits, and reduced albumin and calcium — effects specific to ASGR1 inhibition and not observed with statins.

Animal validation came from ASGR1-deficient pigs (Murata et al. eLife 2021, PMID 34762653)⁷⁷ ASGR1-deficient pigs (Murata et al. eLife 2021, PMID 34762653)
First large-animal model of ASGR1 loss — pigs showed significantly reduced serum LDL-C, reduced atherosclerotic plaque area, and increased hepatic LDLR expression at baseline, which faithfully reproduced the human genetic phenotype in a near-human metabolic model.

Practical Actions

For A-allele carriers at rs55714927, the common-variant effect on LDL-C is modest — roughly 2–5 mg/dL per allele, substantially smaller than the rare del12 loss-of-function (~15 mg/dL). However, because the A allele is present in about 15% of the population, this SNP contributes meaningfully to population-level variation in LDL-C through its additive nature.

The key action point is lipid monitoring: carriers should confirm that the expected non-HDL-C advantage is reflected in measured values. If it is not — particularly in AA homozygotes — other genetic or lifestyle factors may be counteracting it. The effect does not eliminate the need for cardiovascular risk assessment; it modestly improves the starting position.

Interactions

rs55714927 is one of two common GWAS instruments at the ASGR1 locus (the other being rs150688657); both are used together in Mendelian randomization studies to mimic ASGR1 inhibition. The rare variant rs186021206 tags the ASGR1 del12 loss-of-function deletion (r²=0.86) and confers a much larger non-HDL-C reduction (~13–15 mg/dL) — if both rs55714927 and rs186021206 are considered, they represent independent mechanisms at the same gene. In terms of drug interactions, cell and animal data show that ASGR1 inhibition and statin therapy are mechanistically complementary (ASGR1: increases cholesterol excretion; statins: decrease synthesis and increase LDLR recycling), suggesting additive rather than redundant benefits for people already on lipid-lowering therapy.