Evidence-Based Supplement & Herb Guides

Sickle Cell Genetic Test: HBB Gene, Trait, Disease, and Results

Learn how HBB genetic testing distinguishes sickle cell trait from HbSS, HbSC, and sickle beta-thalassemia and clarifies newborn and family results.

A sickle cell genetic test analyzes the HBB gene, which provides instructions for beta-globin, one part of adult hemoglobin. The classic sickle variant changes...

Spinal Muscular Atrophy (SMA) Carrier Test: SMN1 Gene, Copy Number, and Results

Understand SMA carrier testing, including SMN1 copy number, 2+0 silent carriers, duplication markers, residual risk, partner testing, and prenatal results.

A spinal muscular atrophy carrier test estimates whether a person has a nonworking copy of SMN1, the main gene responsible for 5q spinal muscular...

Standard Carrier Screening Panel: Cystic Fibrosis, SMA, Fragile X, and Results

Understand standard carrier screening for cystic fibrosis, SMA, and Fragile X, including test methods, result categories, residual risk, partner testing, and reproductive follow-up.

A standard carrier screening panel commonly combines tests for cystic fibrosis, spinal muscular atrophy, and Fragile X syndrome. The three conditions are grouped for...

Stargardt Disease Genetic Test: ABCA4 Gene Mutations and Results

Learn how ABCA4 genetic testing confirms Stargardt disease, how to interpret two variants, one variant, VUS, negative results, phase, prognosis, and family risk.

A Stargardt disease genetic test looks for the molecular cause of an inherited macular disorder that can begin in childhood, adolescence, or adulthood. Most...

Tay-Sachs Disease Carrier Test: HEXA Gene, Enzyme, and Results

Understand Tay-Sachs carrier testing with HEXA gene and Hex A enzyme analysis, including pseudodeficiency, B1 variants, pregnancy specimens, results, and partner risk.

Tay-Sachs carrier testing can involve two complementary kinds of evidence: the activity of beta-hexosaminidase A enzyme and analysis of the HEXA gene. Both aim...

Tuberous Sclerosis Genetic Test: TSC1, TSC2 Genes, Risk, and Results

Understand TSC1 and TSC2 genetic testing for tuberous sclerosis, including diagnostic results, VUS, negative tests, mosaicism, inheritance risk, and surveillance.

A tuberous sclerosis genetic test analyzes TSC1 and TSC2 for variants that disrupt regulation of cell growth. A pathogenic or likely pathogenic variant in...

Wilson Disease Genetic Test: ATP7B Gene Mutations, Copper, and Results

Understand Wilson disease ATP7B genetic testing and copper results, including ceruloplasmin, urine and liver copper, two variants, carrier findings, VUS, and family risk.

A Wilson disease genetic test searches ATP7B for variants that impair the body’s ability to move copper into bile and incorporate it normally into...

X-Linked Carrier Screening Test: Female Carrier Risk and Results

Understand X-linked carrier screening, female carrier risk, inheritance for sons and daughters, test methods, result meanings, health follow-up, and pregnancy options.

X-linked carrier screening looks for disease-associated changes in genes located on the X chromosome. It is often discussed as a reproductive test for women,...

Autoimmune Disease Genetic Risk Test: HLA, Immune Genes, and Results

Learn what an autoimmune disease genetic risk test measures, how HLA and immune-gene results are interpreted, and why positive or negative findings do not provide a diagnosis.

An autoimmune disease genetic risk test looks for inherited DNA differences linked to conditions in which the immune system attacks the body’s own tissues....

Common Variable Immunodeficiency (CVID) Genetic Test: Immune Disorder Genes and Results

Learn how CVID genetic testing examines immune-disorder genes, what positive, negative, and uncertain results mean, and when a molecular diagnosis may change care.

A common variable immunodeficiency genetic test searches for inherited or newly occurring DNA variants that can cause a CVID-like immune disorder. It may examine...

Complement Deficiency Genetic Test: Immune System Genes and Results

Learn how complement deficiency genetic testing evaluates immune-system genes, how CH50 and AH50 guide diagnosis, and what positive, negative, or uncertain results mean.

A complement deficiency genetic test looks for DNA variants that reduce, eliminate, or dysregulate proteins in the complement system. Complement is a network of...

Crossmatch Test: Transplant Compatibility, Positive Result, and Meaning

Learn how CDC, flow cytometry, and virtual crossmatch tests assess transplant compatibility, what a positive result means, and why donor-specific antibodies affect risk.

A transplant crossmatch test estimates whether a recipient’s antibodies are likely to attack cells from a specific donor. A negative crossmatch generally supports immunologic...

Donor-Specific Antibody (DSA) Test: Transplant Rejection Risk and Results

Understand donor-specific antibody testing, including positive and negative DSA results, MFI, rejection risk, crossmatch findings, limitations, and follow-up after transplant.

A donor-specific antibody test looks for antibodies that recognize human leukocyte antigen, or HLA, markers carried by a particular organ or stem-cell donor. These...

Familial Mediterranean Fever Genetic Test: MEFV Gene, Inflammation, and Results

Learn how MEFV testing supports familial Mediterranean fever diagnosis, including variants, carrier results, colchicine treatment, and amyloidosis risk.

A familial Mediterranean fever genetic test looks for variants in the MEFV gene, which provides instructions for making pyrin, a protein that helps regulate...

Hereditary Angioedema Genetic Test: SERPING1, F12, PLG, and Results

Understand hereditary angioedema genetic testing for SERPING1, F12, PLG, and other genes, including result meanings, inheritance, complement tests, and emergency care.

A hereditary angioedema genetic test looks for inherited variants that can cause repeated swelling through excessive bradykinin activity. The most common form involves SERPING1,...

HLA Antibody Test: Transplant Compatibility, PRA, and Results

Understand HLA antibody testing, including PRA and cPRA, MFI, sensitization, donor-specific antibodies, transplant compatibility, limitations, and follow-up results.

An HLA antibody test checks blood for antibodies against human leukocyte antigen markers. These antibodies can develop after pregnancy, blood transfusion, or a previous...

HLA Matching Test: Kidney, Bone Marrow, Organ Transplant, and Results

Understand HLA matching for kidney, bone marrow, stem-cell, and organ transplant, including 6/6, 8/8, 10/10, haploidentical, mismatch, antibody, and crossmatch results.

An HLA matching test compares inherited human leukocyte antigen markers between a transplant recipient and a potential donor. The meaning of a “good match”...

HLA Typing Test: Immune Matching, Transplant, Disease Risk, and Results

Understand HLA typing methods, allele names, resolution, transplant matching, disease associations, drug-reaction risk, specimen issues, and result interpretation.

An HLA typing test identifies a person’s inherited human leukocyte antigen variants. HLA proteins guide immune recognition, so typing is used to match transplant...

HLA-A Genetic Test: Tissue Type, Transplant Matching, and Results

Understand HLA-A genetic testing, including allele names, tissue type, transplant matching, donor-specific antibodies, disease associations, drug risk, and result limitations.

An HLA-A genetic test identifies the two inherited alleles at the HLA-A locus, one of the major class I human leukocyte antigen genes. HLA-A...

HLA-A*31:01 Test: Carbamazepine Hypersensitivity Risk and Results

Understand HLA-A*31:01 testing for carbamazepine hypersensitivity, including positive and negative results, HLA-B*15:02 differences, drug decisions, and urgent symptoms.

The HLA-A31:01 test checks for an inherited immune-system allele associated with a higher risk of carbamazepine hypersensitivity. Carbamazepine is used for epilepsy, trigeminal neuralgia,...