Evidence-Based Supplement & Herb Guides

HLA-DR Genetic Test: Transplant Matching, Autoimmune Risk, and Results

Understand HLA-DR genetic test results for transplant matching, donor selection, autoimmune susceptibility, HLA antibodies, crossmatch findings, and follow-up.

An HLA-DR genetic test identifies variants in immune-system genes that encode HLA class II proteins, especially HLA-DRB1 and, when present, DRB3, DRB4, or DRB5....

HLA-DRB1 Test: Rheumatoid Arthritis Risk, Shared Epitope, and Results

Learn what an HLA-DRB1 shared epitope test means for rheumatoid arthritis susceptibility, positive and negative results, smoking interaction, diagnosis, and follow-up.

An HLA-DRB1 test can identify “shared epitope” alleles associated with a higher chance of developing rheumatoid arthritis, especially rheumatoid factor–positive or anti-CCP–positive disease. The...

Killer Cell Immunoglobulin-Like Receptor (KIR) Test: Immune Genetics and Results

Understand KIR genetic test results, activating and inhibitory receptors, HLA-C ligands, AA and B/x genotypes, transplant uses, limitations, and next steps.

A killer cell immunoglobulin-like receptor, or KIR, test identifies inherited genes and sometimes alleles that regulate natural killer cells. Natural killer cells help control...

Panel Reactive Antibody (PRA) Test: Transplant Sensitization and Results

Understand PRA and calculated PRA transplant results, sensitization percentages, donor-specific antibodies, crossmatch testing, waiting-list impact, and next steps.

A panel reactive antibody test estimates how broadly a transplant candidate has antibodies against human leukocyte antigens, or HLA. Modern programs often use calculated...

Periodic Fever Syndrome Genetic Panel: Autoinflammatory Genes and Results

Understand periodic fever syndrome genetic panel results, including MEFV, MVK, TNFRSF1A, NLRP3, positive findings, VUS results, negative tests, and follow-up.

A periodic fever syndrome genetic panel looks for inherited or newly occurring variants in genes that regulate innate immunity and inflammation. It can help...

Primary Immunodeficiency Genetic Panel: Immune Disorder Genes and Results

Understand primary immunodeficiency genetic panel results, including immune disorder genes, pathogenic variants, VUS findings, negative tests, treatment impact, and family testing.

A primary immunodeficiency genetic panel tests many genes linked to inborn errors of immunity, a large group of disorders that can cause unusual infections,...

Severe Combined Immunodeficiency (SCID) Genetic Test: Immune Deficiency Genes and Results

Learn how SCID genetic testing identifies immune deficiency genes, explains positive, negative, carrier, and VUS results, and guides urgent treatment and family testing.

A severe combined immunodeficiency genetic test looks for inherited changes that prevent T cells—and often B cells or natural killer cells—from working normally. SCID...

Autosomal Dominant Genetic Test: Inheritance Risk and Results

Learn how autosomal dominant genetic tests work, what a 50% inheritance risk means, and how to interpret positive, negative, de novo, and VUS results.

An autosomal dominant genetic test looks for a disease-causing change in a gene where one altered copy can be enough to affect health. The...

Autosomal Recessive Genetic Test: Carrier Risk and Results

Understand autosomal recessive genetic tests, carrier results, 25% pregnancy risk, partner testing, residual risk after a negative result, and reproductive options.

An autosomal recessive genetic test looks for harmful changes in genes where a person usually needs two disease-causing copies—one from each biological parent—to have...

Carrier Screening Test: Genetic Disease Risk, Results, and What It Means

Learn what carrier screening tests show, how positive and negative results affect genetic disease risk, why partner testing matters, and what options follow an at-risk result.

Carrier screening checks whether a person has a genetic variant that could contribute to an inherited condition in a biological child. It is most...

Chromosome Analysis Test: Karyotype, Abnormal Chromosomes, Genetic Disorders, and Results

Learn what a chromosome analysis and karyotype can detect, how abnormal, balanced, mosaic, and normal results are reported, and when microarray or FISH is needed.

A chromosome analysis test, commonly called a karyotype, examines the number and large-scale structure of chromosomes in dividing cells. It can identify an extra...

DNA Test: What It Shows, How It Works, and Results Explained

Learn what DNA tests can show, how sequencing and genotyping work, what positive, negative, and VUS results mean, and which limitations matter before acting.

A DNA test examines genetic material to answer a defined question about health, inheritance, medication response, biological relationships, ancestry, or identity. It does not...

Genetic Diagnostic Test: Positive, Negative, Variant, and Results Explained

Understand positive, negative, and uncertain genetic diagnostic test results, including variant classifications, test limits, family implications, and follow-up.

A genetic diagnostic test looks for a DNA change that may explain a person’s symptoms, physical findings, abnormal laboratory results, or family history. Unlike...

Genetic Panel Test: Multiple Genes, Disease Risk, and Results

Learn how genetic panel tests analyze multiple genes, when panels are useful, how positive, negative, and uncertain results are interpreted, and what limits to consider.

A genetic panel test examines several genes at the same time to look for variants linked to a particular disease, symptom pattern, or inherited...

Genetic Screening Test: Disease Risk, Results, and What It Means

Understand genetic screening tests, disease-risk estimates, positive and negative results, false results, residual risk, and the follow-up needed for confirmation.

A genetic screening test looks for signs that a person, pregnancy, newborn, or population may have an increased chance of a genetic condition. Screening...

Genetic Testing: Types, Benefits, Risks, Results, and What They Mean

Explore genetic testing types, benefits, risks, accuracy, positive and negative results, uncertain variants, privacy issues, and how to choose appropriate follow-up.

Genetic testing examines DNA, chromosomes, RNA, or related biological signals to answer a medical question. It may confirm an inherited disorder, estimate future disease...

Genetic Variant Test: Pathogenic, Benign, VUS, and Results Explained

Understand pathogenic, likely pathogenic, benign, likely benign, and VUS genetic test results, including classification evidence, family testing, and reclassification.

A genetic variant test identifies differences in DNA and evaluates whether they are likely to affect health. The test may target one known family...

Germline Genetic Testing: Inherited Mutations, Family Risk, and Results

Learn how germline genetic testing identifies inherited variants, explains family risk, distinguishes positive and negative results, and guides cascade testing and follow-up.

Germline genetic testing looks for DNA variants that were present from conception and can potentially be passed to children. These variants are usually found...

Mitochondrial DNA (mtDNA) Test: Mutations, Inheritance, and Results

Understand what an mtDNA test detects, how heteroplasmy and tissue choice affect results, what maternal inheritance means, and what to do after a positive, uncertain, or negative finding.

A mitochondrial DNA test looks for harmful changes in the small circle of DNA inside mitochondria, the energy-producing structures found in nearly every cell....

Newborn Genetic Screening Test: Conditions, Results, and Follow-Up

Learn how newborn genetic screening works, which conditions it checks, what abnormal and normal results mean, and how repeat testing and urgent follow-up protect a baby’s health.

Newborn screening is a public health program that checks babies for serious conditions before symptoms are obvious. In the United States, it usually includes...