SLCO1B1 rs72547530: Statin and Drug Transport Impact

What each genotype means

Understanding rs72547530 and the SLCO1B1 Gene

The single nucleotide polymorphism rs72547530 is a coding change located on chromosome 12 within the SLCO1B1 gene. This gene encodes Organic Anion Transporting Polypeptide 1B1 (OATP1B1), an influx transporter expressed predominantly on the basolateral membrane of human hepatocytes. OATP1B1 functions as a molecular gateway, taking up endogenous molecules such as bile acids and bilirubin, as well as exogenous pharmaceutical compounds, into the liver for metabolism and biliary excretion. At the molecular level, rs72547530 involves an exchange leading to the p.Pro155Thr substitution, which is a defining component of specific pharmacogenomic star alleles, notably SLCO1B1*14 and *37. Because OATP1B1 plays a rate-limiting role in hepatic clearance, alterations in its protein sequence can alter drug uptake efficiency. While foundational research on SLCO1B1 has historically focused on other common variants like rs4149056 (c.521T>C), secondary variants such as rs72547530 are increasingly scrutinized for their contribution to unexplained variation in drug kinetics.

Pharmacogenomic Evidence: Statins and Methotrexate

Genetic variation in SLCO1B1 is most extensively studied in the context of 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors, commonly known as statins, as well as antifolate chemotherapies like methotrexate. Pharmacological studies associate altered OATP1B1 transport with shifts in systemic exposure: reduced transport leaves more circulating active drug in plasma, elevating the risk of adverse events like statin-associated musculoskeletal symptoms, while increased transport accelerates liver clearance. For rs72547530 specifically, scientific literature categorizes the clinical evidence strength as limited. In vitro transport assays and targeted pharmacokinetic studies show that the Pro155Thr substitution modifies transporter substrate affinity and clearance rates for compounds like methotrexate and certain statin metabolites. However, large-scale prospective clinical trials evaluating rs72547530 in isolation remain scarce. Instead, pharmacogenomic consortia like the Clinical Pharmacogenetics Implementation Consortium (CPIC) assess patient profiles using broader haplotype or diplotype frameworks, which incorporate this variant alongside other co-inherited markers to estimate overall transporter activity.

Population Patterns and Ancestral Distribution

The rs72547530 variant is relatively uncommon across global human populations compared to standard pharmacogenetic variants. In European and East Asian cohorts, catalog records and population sequencing databases report minor allele frequencies typically between 1% and 2%. In contrast, related missense variations at codon 155 show distinct patterns across diverse ancestral backgrounds, occasionally reaching slightly higher representation in specific African or admixed reference panels. Because the variant occurs at modest frequencies, homozygous carriers of the minor allele are rare in the general public, with most individuals carrying two copies of the ancestral major allele. International pharmacogenomics initiatives emphasize that historical genomic studies underrepresented non-European ancestries, meaning current database statistics may not fully capture the global diversity of rare SLCO1B1 haplotypes. Continued multiancestry sequencing is underway to refine frequency estimates and identify population-specific co-inheritance patterns.

Clinical Utility and Next Steps for Individuals

Finding an SLCO1B1 variant such as rs72547530 on a genetic test provides educational context about individual biological differences in drug processing, but it is not a direct medical diagnosis. Prescribing guidelines created by groups like CPIC and the Dutch Pharmacogenetics Working Group (DPWG) incorporate validated SLCO1B1 alleles to guide statin choice and dosing; however, these guidelines rely on comprehensive diplotype calling rather than isolated single-SNP reads. An individual should never stop, start, or alter the dosage of any prescribed statin, methotrexate, or other medication based on genetic testing results alone. Many clinical factors—including age, kidney function, liver health, and concomitant interacting medications—strongly influence drug safety and efficacy alongside genetics. Anyone with questions regarding their pharmacogenomic profile or potential medication side effects should discuss these findings directly with their physician or clinical pharmacist.

Frequently asked questions

Sources & further reading

Related variants in SLCO1B1