Pharmacogenomics Terminology

A numerical value that indicates how well an enzyme functions based on your genetic variants. Higher scores mean more enzyme activity, affecting how quickly medications are metabolized.

Stands for Absorption, Distribution, Metabolism, and Excretion—the four stages of how your body processes medications. Genetics can affect each stage.

One version of a gene. You inherit two alleles for each gene - one from each parent. Different alleles can lead to different traits or medication responses.

The percentage of a medication that reaches your bloodstream and is available to have an effect. Genetics can influence how much of a drug your body absorbs.

A protective barrier that controls what substances can enter the brain from the bloodstream. Some genetic variants affect how medications cross this barrier.

Having two different variant versions of a gene (neither is the standard version). For example, *3/*4 means both parents gave you different variant copies, which can significantly affect how you metabolize medications.

An enzyme that breaks down neurotransmitters like dopamine, epinephrine, and norepinephrine. Genetic variants affect mental health, stress response, and pain sensitivity.

A measure of how confident we are in a genetic analysis, based on data quality, research evidence strength, and guideline alignment.

An international group that creates evidence-based guidelines for how to use genetic information in prescribing medications.

A family of enzymes in your liver responsible for metabolizing most medications. Common CYP enzymes include CYP2D6, CYP2C19, and CYP3A4.

The combination of both alleles you inherited for a gene, one from each parent. For example, CYP2D6 *1/*4 means you inherited the *1 variant from one parent and *4 from the other.

When your genetics affect how two medications interact with each other. Your genetic profile may amplify or change the risk of medication interactions.

When a specific genetic variant affects how a medication works in your body. These interactions can influence effectiveness and side effect risk.

A protein that speeds up chemical reactions in your body, including breaking down medications. Genetic variants can affect how well your enzymes work, changing how you process drugs.

A substance (medication, food, or supplement) that increases enzyme activity, causing medications to be processed faster and potentially reducing their effectiveness.

A substance that decreases enzyme activity, causing medications to be processed slower and potentially increasing side effects or toxicity.

The strength of scientific evidence supporting a genetic finding, ranging from emerging research to well-established clinical guidelines (Level A = Strong, Level B = Moderate, Level C = Optional).

Genetic markers that the FDA has identified as important for certain medications. These may appear on medication labels with dosing guidance.

A segment of DNA that contains instructions for making proteins. Genes determine traits and how your body functions.

Your specific combination of alleles for a gene (e.g., CC, CT, or TT). Your genotype determines how you might respond to certain medications.

The time it takes for half of a medication to be eliminated from your body. Genetic variants can make half-lives longer or shorter than typical.

Having two different versions of a gene—typically one standard version and one variant version. For example, *1/*4 means you inherited a normal copy from one parent and a variant from the other.

Having two identical copies of a gene variant—one from each parent. For example, *1/*1 (both normal) or *4/*4 (both variant). This means both parents passed you the same version.

Someone whose genetics cause them to break down certain medications slower than normal but not as slowly as a poor metabolizer. May need dose adjustments.

The chemical processes your body uses to break down and process substances, including medications, nutrients, and toxins. Your genetics play a major role in determining your metabolic rate.

How quickly or slowly your body breaks down medications. Categories include Poor, Intermediate, Normal, Rapid, and Ultra-Rapid Metabolizer.

A biochemical process that adds methyl groups to DNA or other molecules. Important for neurotransmitter production, detoxification, and gene regulation. MTHFR gene variants affect this process.

An enzyme involved in processing folate and methylation. Common variants (C677T, A1298C) can affect neurotransmitter production and medication response.

Someone whose genetics allow them to break down medications at a typical rate. Standard dosing usually works well.

How a medication affects your body - including its therapeutic effects and side effects. Genetic variants can influence how well a medication works.

The study of how single genes affect drug response. Often used interchangeably with pharmacogenomics, though pharmacogenomics typically refers to genome-wide analysis.

The study of how your genes affect your body's response to medications. This helps predict which medications will work best and which might cause side effects.

How your body processes a medication - including absorption, distribution, metabolism, and elimination. Genetics can affect each of these stages.

A comprehensive database that curates knowledge about how genetic variation affects drug response, maintained by Stanford University.

The central repository for pharmacogene variation that standardizes star allele nomenclature and provides the definitive catalog of allele definitions.

The observable result of your genotype - such as being a 'poor metabolizer' or 'rapid metabolizer' of certain medications.

Taking multiple medications at the same time. Genetics can affect how medications interact with each other in your body.

Someone whose genetics cause them to break down certain medications very slowly. This can lead to higher medication levels and increased side effect risk.

A medication that must be converted by your body into its active form. Poor metabolizers may not activate prodrugs effectively, reducing their benefit.

Someone whose genetics cause them to break down certain medications faster than normal. Higher doses may be needed for effectiveness.

The most common or 'standard' version of a gene in the population, typically designated as *1. Other alleles are compared against this reference.

A unique identifier for a specific genetic variant (e.g., rs1801133). The 'rs' stands for 'reference SNP' and helps scientists and doctors refer to the same genetic variant.

A variation in a single letter of your DNA code. SNPs are the most common type of genetic variation and can affect how medications work in your body.

A naming system for gene variants (e.g., *1, *2, *4). The *1 allele is typically the 'normal' or reference version. Other star alleles (like *4 or *17) indicate variants with different activity levels.

A medication or substance that is processed by a specific enzyme. For example, codeine is a substrate of CYP2D6.

The range between an effective dose and a toxic dose of a medication. Narrow therapeutic index drugs require more careful dosing based on genetics.

Proteins that move medications into or out of cells. Genetic variants in transporter genes (like SLCO1B1) can affect drug levels and side effects.

Someone whose genetics cause them to break down certain medications very quickly. Standard doses may not be effective.

A version of a gene that differs from the reference or 'normal' version. Variants can increase, decrease, or have no effect on gene function.

The normal or most common version of a gene in the population. Often used interchangeably with 'reference allele' or *1 designation.