Overview
Boston Heart Statin Induced Myopathy (SLCO1B1) Genotype Test
The SLCO1B1 gene is critical to the body’s uptake and metabolism of statins, drugs prescribed to reduce LDL-C levels for the prevention of heart attacks or strokes. Statin associated muscle symptoms (SAMS)—the onset of muscle aches, spasms, weakness and/or pain associated with statin therapy— are considered to be the most frequent adverse events associated with statins. 1-2
60% of patients who stopped taking a statin cited muscle pain as the primary reason for discontinuation.1 About 25% of people carry either one or two copies of the SLCO1B1 variant.3-5 This increases their risk up to 4.5-fold – or 17-fold respectively for developing significant statin induced myopathy (muscle aches, pains or weakness with significant creatine kinase elevation) due to statins.6 Research shows that patients who received SLCO1B1 genotype guided therapy were more likely to fill the statin prescription, take the medication and have a greater decrease in LDL cholesterol.7
The Boston Heart Statin Induced Myopathy (SLCO1B1) Genotype test identifies those patients who are at higher risk of developing statin induced myopathy due to a variation on their SLCO1B1 gene. This test helps healthcare providers identify patients who are at higher risk for such negative side effects and prescribe the right statin type and dose with the least probability of causing myopathy.
The SLCO1B1 genotype was identified by University of Oxford. Boston Heart holds the exclusive U.S. license for the SLCO1B1 genotype test.
References:
1. Wei MY, Ito MK, Cohen JD, Brinton EA, Jacobson TA. Predictors of statin adherence, switching, and discontinuation in the USAGE survey: understanding the use of statins in America and gaps in patient education. J Clin Lipidol. 7(5):472-483.
2. Stroes ES, Thompson PD, Corsini A, et al. Statin-associated muscle symptoms: impact on statin therapy—European Atherosclerosis Society Consensus Panel Statement on Assessment, Aetiology and Management. Eur Heart J. 2015;36(17):1012-1022.
3. Voora D, Shah SH, Spasojevic I, Ginsburg G. The SLCO1B1*5 genetic variant is associated with statin-induced side effects. J Am Coll Cardiol2009;54(17):1609-1616.
4. Akao H, Polisecki E, Kajinami K, Trompet S, Robertson M, Ford I, Jukema JW, de Craen AJ, Westendorp RG, Shepherd J, Packard C, Buckley BM, Schaefer EJ. Genetic Variation at the SLCO1B1 Gene Locus and Low Density Lipoprotein Cholesterol Lowering Response to Pravastatin in the Elderly. Atherosclerosis 2012;220(2):413-417.
5. Boston Heart Diagnostics. Database of over 240,000 samples.
6. SEARCH Collaborative Group. SLCO1B1 variants and statin-induced myopathy – a genomewide study. N Engl J Med 2008;359(8):789-799.
7. Li JH, Joy SV, Haga SB, et al. Genetically guided statin therapy on statin perceptions, adherence, and cholesterol lowering: a pilot implementation study in primary care patients. J Pers Med. 2014;4(2):147-162.
Test Details
Boston Heart Statin Induced Myopathy (SLCO1B1) Genotype Test
Solute carrier organic anion transporter (SLCO1B1) encodes for the organic anion transporting polypeptide 1B1 (OATP1B1) which is an influx transporter produced in the liver that mediates the hepatic uptake and metabolism of statins. Inherited variations in the SLCO1B1 gene known as SNPs (single nucleotide polymorphisms) affect the function of this transporter. The intended use of SLCO1B1 testing is as an aid in the selection of the appropriate statin for treatment in individuals. The genetic test identifies individuals with a specific drug transporter defect associated with statin-induced myopathy, thus allowing the healthcare provider to select a statin that is less likely to cause this adverse event.
Methodology
Real time polymerase chain reaction (PCR)
Patient Preparation
None
Preferred Specimen
1.0 mL whole blood collected in EDTA (Lavender Top) tube
Alternate Specimen
- Buccal swab
- Dried Blood collected on an AdvanceDx 100 card
Transport Temperature
Refrigerated (ship on frozen cold packs)
Stability
Refrigerated: 15 days
Lab Values
Boston Heart Statin Induced Myopathy (SLCO1B1) Genotype Test
- Normal Statin Transporter : Genotype T/T (valine/valine)
- Decreased Statin Transporter: Genotype T/C (valine/alanine)
- Markedly Decreased Statin Transporter: Genotype C/C (alanine/alanine)
Clinical Significance
Boston Heart Statin Induced Myopathy (SLCO1B1) Genotype Test
- The T/T genotype – normal statin transporter1
- The T/C genotype – decreased statin metabolizer1
- These patients have a decreased statin transporter. Patients with a T/C genotype have a decreased ability to transport statins; associated with reduced statin efficacy, and up to a 4.5 -fold increased risk of developing muscle pain on statin therapy.
- The C/C genotype – markedly decreased statin transporter1
- Markedly decreased statin transporter. Patients with a C/C genotype have a significantly decreased ability to transport statins; associated with reduced statin efficacy and up to a 17-fold increased risk of developing muscle pain on statin therapy.
References:
- SEARCH Collaborative Group. SLCO1B1 variants and statin-induced myopathy – a genomewide study. N Engl J Med. 2008;359(8):789-799.
Treatment Options
Boston Heart Statin Induced Myopathy (SLCO1B1) Genotype Test
- T/T genotype: Standard doses of statins, if indicated, are recommended
- T/C genotype: Moderate to low doses of water soluble statins (in order of solubility: pravastatin, pitavastatin, rosuvastatin or fluvastatin), if indicated, are recommended
- C/C genotype: Low doses of water soluble statins (in order of solubility: pravastatin, pitavastatin, rosuvastatin or fluvastatin), if indicated, are recommended
