Evidence-Based Supplement & Herb Guides

Alzheimer Disease Genetic Test: APOE, APP, PSEN1, PSEN2, and Results

Understand Alzheimer disease genetic testing for APOE, APP, PSEN1, and PSEN2, including who should test, result meanings, family risk, and treatment safety.

Alzheimer disease genetic testing can answer very different questions depending on which genes are examined. Rare pathogenic variants in APP, PSEN1, or PSEN2 can...

Amyotrophic Lateral Sclerosis (ALS) Genetic Test: C9orf72, SOD1, TARDBP, and Results

Learn how ALS genetic testing evaluates C9orf72, SOD1, TARDBP, FUS, and other genes, what results mean, and how findings can affect treatment and family risk.

ALS genetic testing looks for inherited or disease-associated changes that may explain why motor neurons are degenerating. The most important first-line targets include the...

Angelman Syndrome Genetic Test: UBE3A, Methylation, Deletion, and Results

Understand Angelman syndrome genetic testing for UBE3A, methylation, deletions, uniparental disomy, and imprinting defects, including results and recurrence risk.

Angelman syndrome testing does more than look for a change in the UBE3A gene. The condition results from loss of the active maternal UBE3A...

APOE Genotype Test: Alzheimer Disease Risk, Cholesterol, and Results

Learn what an APOE genotype test shows about Alzheimer disease risk, cholesterol disorders, anti-amyloid treatment safety, and ε2, ε3, and ε4 results.

An APOE genotype test identifies which common APOE alleles—ε2, ε3, or ε4—you inherited from each biological parent. The result can inform several separate clinical...

Autism Genetic Testing: Chromosomal Microarray, Exome Sequencing, and Results

Learn how chromosomal microarray, exome sequencing, genome sequencing, and targeted tests are used in autism, what results mean, and how findings may guide care.

Genetic testing does not diagnose autism; autism is diagnosed from development, communication, behavior, and clinical observation. Genetic testing looks for an underlying chromosome or...

Becker Muscular Dystrophy Genetic Test: DMD Gene, Muscle Weakness, and Results

Learn how Becker muscular dystrophy genetic testing detects DMD deletions, duplications, and sequence variants, and what results mean for weakness, heart care, and family risk.

Becker muscular dystrophy testing looks for a pathogenic change in the DMD gene, which provides instructions for making dystrophin. Becker muscular dystrophy usually occurs...

C9orf72 Genetic Test: ALS, Frontotemporal Dementia, and Results

Understand how C9orf72 repeat expansion testing relates to ALS and frontotemporal dementia, how results are classified, and what they mean for family risk.

A C9orf72 genetic test looks for an abnormal expansion of the six-letter DNA sequence GGGGCC in the C9orf72 gene. This expansion is an important...

Charcot-Marie-Tooth Disease Genetic Test: PMP22, GJB1, MFN2, MPZ, and Results

Learn how Charcot-Marie-Tooth genetic testing evaluates PMP22, GJB1, MFN2, MPZ, copy-number changes, inheritance, and positive, negative, or uncertain results.

Charcot-Marie-Tooth disease genetic testing searches for an inherited cause of a slowly progressive peripheral neuropathy. The most frequent findings involve PMP22, GJB1, MFN2, or...

Congenital Myasthenic Syndrome Genetic Test: Neuromuscular Junction Genes and Results

Understand congenital myasthenic syndrome genetic panels, neuromuscular junction genes, result categories, inheritance, and why the exact subtype can change treatment.

Congenital myasthenic syndrome genetic testing looks for inherited variants that disrupt communication between a motor nerve and muscle at the neuromuscular junction. These disorders...

CYP2D6 and CYP2C19 Psychiatric Medication Pharmacogenetic Test: Antidepressant Results

Understand CYP2D6 and CYP2C19 antidepressant pharmacogenetic results, metabolizer phenotypes, drug interactions, dosing implications, and test limitations.

A CYP2D6 and CYP2C19 psychiatric medication pharmacogenetic test examines inherited differences in two liver-enzyme genes that help process many antidepressants. The result may explain...

Developmental Delay Genetic Test: DNA Variants, Diagnosis, and Results

Learn how developmental delay genetic testing uses microarray, exome, genome, Fragile X, and targeted tests, and how to interpret positive, negative, and uncertain results.

A developmental delay genetic test looks for DNA changes that may explain why a child is learning, moving, speaking, or developing daily-living skills later...

Dravet Syndrome Genetic Test: SCN1A Gene Mutations and Results

Understand SCN1A genetic testing for Dravet syndrome, including who should be tested, variant results, treatment implications, inheritance, mosaicism, and negative tests.

A Dravet syndrome genetic test usually looks for disease-causing variants in SCN1A, the gene most often responsible for this severe developmental and epileptic encephalopathy....

Duchenne Muscular Dystrophy Genetic Test: DMD Gene, Deletions, and Results

Understand DMD genetic testing for Duchenne muscular dystrophy, including exon deletions, duplications, sequencing, reading-frame results, treatment eligibility, and carrier risk.

A Duchenne muscular dystrophy genetic test looks for disease-causing changes in the DMD gene, which provides instructions for dystrophin, a protein that protects muscle...

Epilepsy Genetic Panel Test: Seizure Genes, Diagnosis, and Results

Learn how epilepsy genetic panel testing evaluates seizure genes, who benefits, how to interpret positive, uncertain, and negative results, and when findings can guide treatment.

An epilepsy genetic panel test analyzes many genes associated with recurrent seizures and epilepsy syndromes at the same time. It is most likely to...

Facioscapulohumeral Muscular Dystrophy Genetic Test: D4Z4 Repeat, SMCHD1, and Results

Understand FSHD genetic testing, including D4Z4 repeat size, permissive 4qA haplotypes, SMCHD1, methylation, FSHD1 versus FSHD2, mosaicism, and results.

A facioscapulohumeral muscular dystrophy genetic test evaluates a specialized DNA repeat region called D4Z4 near the end of chromosome 4 and, in selected cases,...

Fragile X Genetic Test: FMR1 CGG Repeats, Autism, and Results

Understand Fragile X FMR1 testing, CGG repeat ranges, methylation, mosaicism, autism-related features, premutation risks, AGG interruptions, and family results.

A Fragile X genetic test measures the number of CGG repeats in the FMR1 gene and usually assesses whether an expanded repeat is methylated....

Friedreich Ataxia Genetic Test: FXN Gene, GAA Repeats, and Results

Understand Friedreich ataxia genetic testing, FXN GAA repeat ranges, positive and carrier results, inheritance, limitations, and follow-up care.

Friedreich ataxia genetic testing looks for disease-causing changes in the FXN gene, most often an abnormal expansion of a GAA DNA repeat. The test...

Frontotemporal Dementia Genetic Test: MAPT, GRN, C9orf72, and Results

Learn how MAPT, GRN, and C9orf72 testing is used in frontotemporal dementia, what positive or uncertain results mean, and how relatives are affected.

Frontotemporal dementia genetic testing looks for inherited causes of progressive changes in behavior, personality, language, executive function, or movement. The three most common genes...

GBA Genetic Test: Parkinson Disease Risk, Gaucher Disease, and Results

Understand GBA genetic testing for Parkinson disease risk and Gaucher disease, including methods, variant results, inheritance, limitations, and follow-up.

A GBA genetic test looks for changes in the GBA1 gene, which provides instructions for the lysosomal enzyme glucocerebrosidase. The same gene can be...

Hereditary Ataxia Genetic Test: Spinocerebellar Ataxia Genes and Results

Learn how hereditary ataxia genetic testing detects SCA genes and repeat expansions, what positive, negative, and uncertain results mean, and when broader testing helps.

A hereditary ataxia genetic test searches for inherited DNA changes that can cause poor balance, unsteady walking, slurred speech, abnormal eye movements, limb incoordination,...