A transport protein is a protein in the blood that binds poorly soluble substances, allowing them to be split off or released again in another location. The protein SLCO1B1 (full name: solute carrier anion transporter 1B1) is responsible for detoxification and the transport of substances from the blood to the liver. SLCO1B1 is not only involved in the transport of endogenous substances, such as bile acids, steroids and hormones, but also of xenobiotics, such as drugs.
An important group of drugs that are transported to the liver by the transport protein SLCO1B1 are statins (cholesterol-lowering drugs) such as pravastatin, lovastatin, rosuvastatin, atorvastatin and simvastatin.
ACE inhibitors (used to treat hypertension and chronic heart failure) and methotrexate (used to treat rheumatoid arthritis) are also transported to the liver with the help of SLCO1B1.
Genetic predisposition
The activity of the transport protein SLCO1B1 varies from one individual to another.
This variation can be partly explained by genetic variations in the SLCO1B1 gene. Around 20 to 25% of people with a European background have reduced SLCO1B1 activity and 0 to 6% significantly reduced activity.
If you have such reduced activity, there is a risk that statins, in particular atorvastatin and simvastatin, can cause side effects such as myopathy (muscle problems) and rhabdomyolysis (muscle breakdown).
When a genotype is determined variations in the SLCO1B1 gene are indicated by two so-called alleles. Each allele has a name consisting of an asterisk (*) and a number. An example of a possible SLCO1B1 genotype is SLCO1B1*1/*5.
At iGene we determine the following variants (alleles) of the SLCO1B1 gene:
SLCO1B1*5, SLCO1B1*15 and other (classified as SLCO1B1*1).