[ Reference · Genetics A–Z ]

The Genetics Glossary — 31 Terms, Plain English

BRCA1 to VKORC1, star alleles to polygenic risk scores — the vocabulary of modern genetic testing, defined in two or three sentences each, with a link to the test or guide where that term becomes actionable.

Maintained by the Gene Matrix clinical teamMedically reviewed by Shawn Desai, MD, PhDAugust 2026
[ 31 Terms ][ Cancer · PGx · Nutrition ][ Client-Side Filter ]

The Terms, A–Z

[ 31 Definitions · Plain English ]
31 / 31
Gene · Hereditary Cancer

BRCA1

A tumor-suppressor gene that repairs damaged DNA. Pathogenic BRCA1 variants raise lifetime breast cancer risk to up to 72% and ovarian cancer risk to up to 44%. Testing is the first step in NCCN-guided enhanced screening.

BRCA Test →
Gene · Hereditary Cancer

BRCA2

BRCA1's partner in DNA repair. Variants raise breast, ovarian, prostate, and pancreatic cancer risk — including up to 27% lifetime prostate cancer risk in men by age 80.

BRCA Test →
Syndrome · Hereditary Cancer

Lynch Syndrome

The most common hereditary colorectal cancer syndrome, caused by variants in MLH1, MSH2, MSH6, PMS2, or EPCAM. It raises lifetime colorectal cancer risk to up to 80% and affects roughly 1 in 279 people — most of whom don't know.

Lynch Syndrome Guide →
Gene · Pharmacogenomics

CYP2D6

A liver enzyme gene that metabolizes roughly 20–25% of common medications, including many antidepressants, opioids, and beta-blockers. Your CYP2D6 metabolizer type can make standard doses ineffective or unsafe.

Pharmacogenomics Hub →
Gene · Pharmacogenomics

CYP2C19

Controls metabolism of citalopram, escitalopram, sertraline, clopidogrel, and proton-pump inhibitors. Poor and ultra-rapid metabolizers frequently fail standard therapy — one of the most clinically actionable PGx genes.

Pharmacogenomics Hub →
Gene · Pharmacogenomics

CYP2C9

Metabolizes warfarin, NSAIDs, and several diabetes medications. Alongside VKORC1, it determines safe warfarin dosing — a pairing CPIC guidelines cover explicitly.

Pharmacogenomics Hub →
Gene · Pharmacogenomics

CYP3A4

The liver's most abundant drug-metabolizing enzyme, processing statins, immunosuppressants, and a large share of all prescription drugs. Variants and drug interactions here drive many adverse events.

GenePGx Test →
Gene · Pharmacogenomics

SLCO1B1

A transporter gene that moves statins into the liver. The SLCO1B1 decreased-function variant raises simvastatin muscle-toxicity (myopathy) risk — CPIC guidelines recommend alternative statins or lower doses for carriers.

GenePGx Test →
Gene · Pharmacogenomics

VKORC1

The gene warfarin directly targets. VKORC1 variants change warfarin sensitivity dramatically; combined with CYP2C9, genotype-guided dosing is one of the oldest FDA-recognized pharmacogenomic applications.

GenePGx Test →
Gene · Pharmacogenomics

TPMT

Thiopurine methyltransferase — the enzyme that deactivates thiopurine chemotherapy drugs. Low-activity carriers can develop life-threatening bone-marrow suppression at standard doses, so TPMT testing is standard before treatment.

GenePGx Test →
Gene · Pharmacogenomics

DPYD

Encodes the enzyme that clears fluoropyrimidine chemotherapy (5-FU, capecitabine). DPYD poor metabolizers risk severe, sometimes fatal toxicity at standard doses; CPIC guidelines mandate dose reduction or avoidance.

GenePGx Test →
Gene · Nutrition

MTHFR

Converts folic acid into active folate. Variants carried by up to 60% of people reduce that conversion by 30–70%, making the methylated form of folate the smarter supplement for carriers.

Nutrigenomics Basics →
Gene · Health Risk

APOE

Best known for its role in cholesterol transport and lipid metabolism. APOE variants influence cardiovascular risk profiles and dietary fat response — and the ε4 allele is the strongest common genetic risk factor for late-onset Alzheimer's disease.

GeneCore Test →
Gene · Weight

FTO

The fat mass and obesity-associated gene. Variants found in ~44% of people of European ancestry raise obesity risk by up to 70% via appetite and energy-expenditure pathways — a driver of genetic diet failure, not a destiny.

DNA & Weight Guide →
Field · Medications

Pharmacogenomics (PGx)

The study of how genes affect drug response. Up to 99% of people carry at least one actionable PGx variant, which is why a single PGx panel can guide medication choices for a lifetime.

Pharmacogenomics Hub →
Concept · Pharmacogenomics

Metabolizer Types

Your functional speed at processing a drug: poor (little/no enzyme activity — side effects at standard doses), intermediate (reduced), normal (expected response), rapid, or ultra-rapid (clears the drug before it works). Dose and drug choice should follow the type.

Pharmacogenomics Hub →
Technology

NGS (Next-Generation Sequencing)

Massively parallel DNA sequencing that reads millions of fragments at once — the technology that made 108-gene panels and 230+-gene PGx panels fast and affordable instead of months-long and bespoke.

Our Science →
Certification

CLIA & CAP

CLIA is the U.S. federal standard for laboratory quality; CAP is the College of American Pathologists accreditation program. Gene Matrix testing runs in a CLIA-certified (ID 14D2276402), CAP-aligned, ISO 15189 laboratory — the same class hospitals use.

Our Science →
Product · Hereditary Cancer

GeneCancer

Gene Matrix's 108-gene hereditary cancer panel — BRCA1, BRCA2, the Lynch syndrome genes, TP53, PALB2, and 100+ more — covering 15+ cancer types from an at-home cheek swab, with counseling included for positive results.

GeneCancer Test →
Product · Pharmacogenomics

GenePGx

Gene Matrix's pharmacogenomics panel: 230+ genes covering 700+ medications, aligned to CPIC, FDA, and DPWG guidance. One cheek swab informs prescribing across psychiatry, cardiology, pain, and oncology for life.

GenePGx Test →
Test Type · Family Planning

Carrier Screening

Testing that shows whether you carry a recessive variant you could pass to a child. Carriers are usually healthy themselves, but when both partners carry the same condition, each child has a 25% chance of being affected.

Explore All Tests →
Concept · Risk

Polygenic Risk Score (PRS)

A score combining the small effects of thousands of common variants into an overall risk estimate for a condition like heart disease or diabetes. Powerful at population scale, but an estimate — not a diagnosis — for any individual.

Our Science →
Result Type

Variant of Uncertain Significance (VUS)

A DNA change whose clinical effect isn't yet established. A VUS is not a positive result and shouldn't drive medical decisions; most are eventually reclassified as benign as evidence accumulates — which is why quarterly reinterpretation matters.

108-Gene Panel Explained →
Concept · Pharmacogenomics

Star Allele

The naming system for pharmacogene variants: CYP2D6*4, CYP2C19*2, and so on. Each star allele defines a haplotype with a known effect on enzyme function, and your two alleles combine into your metabolizer type.

Pharmacogenomics Hub →
Concept · Genomics

Haplotype

A set of variants inherited together on the same chromosome. Pharmacogenes are reported as haplotypes (star alleles) because function depends on the combination of variants on each copy — not single SNPs in isolation.

Pharmacogenomics Hub →
Concept · Genomics

SNP (Single Nucleotide Polymorphism)

A single-letter DNA difference between people — the most common type of genetic variation. Consumer chips genotype hundreds of thousands of common SNPs; clinical panels deeply analyze the specific SNPs and variants with proven medical actionability.

Lab Methodology Explained →
Technology

Whole Genome Sequencing (WGS)

Reading essentially all ~3 billion letters of your DNA. Comprehensive for discovery and rare-disease diagnosis, but slower and costlier than targeted panels — overkill when the clinical question concerns known, actionable variants.

Lab Methodology Explained →
Technology · Genomics

Exome

The ~1–2% of the genome that directly codes for proteins — where most known disease-causing variants live. Exome-focused analysis (like GeneCore's 130+-gene health panel) concentrates on the regions with the highest clinical yield.

GeneCore Test →
Field · Nutrition

Nutrigenomics

The study of how genes affect nutrient processing — lactose tolerance (LCT), caffeine clearance (CYP1A2), vitamin D (VDR/GC), folate activation (MTHFR). It's the science behind matching diet to DNA instead of guessing.

Nutrigenomics Basics →
Syndrome · Hereditary Cancer

Hereditary Cancer Syndrome

An inherited pattern — Lynch syndrome, hereditary breast and ovarian cancer (BRCA1/2), Li-Fraumeni (TP53) — where a pathogenic variant sharply raises lifetime risk for specific cancers. Roughly 5–10% of cancers are hereditary, and most carriers don't know.

Hereditary Cancer Screening →
Guidelines · Hereditary Cancer

NCCN Guidelines

The National Comprehensive Cancer Network's evidence-based protocols defining who should get hereditary cancer testing and what to do after a positive result — enhanced screening schedules, risk-reducing options, and cascade testing for relatives.

BRCA Test →

Definitions Are Free. Answers Are $89/mo.

[ 11 Tests · One Membership ]

Every term in this glossary is analyzed somewhere in the Gene Matrix panel suite — BRCA and Lynch in GeneCancer, CYP genes in GenePGx, FTO and MTHFR in GeneDiet. One membership covers all 11 tests at $89/month ($59/mo billed annually, $712/yr), with results in 5–7 days (48-hour priority available). 30-day money-back guarantee.

[ CLIA · CAP · ISO 15189 ][ Counselor Included ][ HSA / FSA Eligible ]