Evidence-Based Supplement & Herb Guides

Preimplantation Genetic Testing (PGT): IVF Embryo Testing and Results

Learn how PGT works in IVF, including PGT-A, PGT-M, and PGT-SR, embryo biopsy, result terms, limitations, transfer decisions, costs, and prenatal follow-up.

Preimplantation genetic testing, or PGT, analyzes a small sample of cells from embryos created through in vitro fertilization before an embryo is selected for...

Preimplantation Genetic Testing for Aneuploidy (PGT-A): Embryo Chromosomes and Results

Explore how PGT-A screens IVF embryos for chromosome abnormalities, what euploid, aneuploid, mosaic, and no-result findings mean, and where evidence and limits apply.

Preimplantation genetic testing for aneuploidy, or PGT-A, screens cells from an IVF embryo for extra or missing chromosomes. The test may help identify embryos...

Preimplantation Genetic Testing for Monogenic Disease (PGT-M): Inherited Disease and Results

Learn how PGT-M tests IVF embryos for a known inherited disease, including assay development, linkage, affected and carrier results, limitations, and prenatal confirmation.

Preimplantation genetic testing for monogenic disease, or PGT-M, tests IVF embryos for a specific condition caused by a variant in one gene. It can...

Preimplantation Genetic Testing for Structural Rearrangements (PGT-SR): Translocations and Results

Understand how PGT-SR tests IVF embryos from translocation or inversion carriers, including normal, balanced, unbalanced, mosaic, and inconclusive results.

Preimplantation genetic testing for structural rearrangements, or PGT-SR, examines IVF embryos for chromosome gains and losses related to a known parental translocation, inversion, or...

Prenatal Chromosomal Microarray Test: Deletions, Duplications, and Results

Prenatal chromosomal microarray testing detects fetal chromosome deletions and duplications. Learn when CMA is used, how results and VUS are interpreted, and its limits.

A prenatal chromosomal microarray test examines fetal DNA for missing or extra chromosome material, including changes too small to be seen on a standard...

Prenatal Exome Sequencing Test: Fetal Anomalies, Genetic Diagnosis, and Results

Prenatal exome sequencing can diagnose single-gene causes of fetal anomalies. Learn who may be offered testing, diagnostic yield, result types, limits, and next steps.

Prenatal exome sequencing is an advanced diagnostic test used when fetal ultrasound findings suggest a possible single-gene disorder, especially after chromosome testing has not...

Prenatal Genetic Screening Test: Chromosome Conditions, Risk, and Results

Prenatal genetic screening estimates the chance of chromosome conditions. Compare cfDNA, serum, and ultrasound screening, understand results, and learn when diagnosis is needed.

Prenatal genetic screening estimates the chance that a pregnancy is affected by selected chromosome conditions; it does not confirm whether the fetus has one....

Prenatal Karyotype Test: Chromosome Abnormalities and Results

A prenatal karyotype diagnoses chromosome number and structural abnormalities. Learn how CVS or amniocentesis results are written, what mosaicism means, and when other tests are needed.

A prenatal karyotype is a diagnostic test that examines the number and large-scale structure of fetal chromosomes. It can identify whole-chromosome conditions such as...

Prenatal Microdeletion Test: 22q11.2 Deletion, Risk, and Results

Prenatal 22q11.2 microdeletion testing may be screening or diagnostic. Learn how cfDNA differs from microarray, how positives are confirmed, and what a deletion can mean.

A prenatal microdeletion test can mean either a maternal blood screening test or diagnostic testing of placental or fetal cells. These approaches are not...

Products of Conception (POC) Genetic Test: Miscarriage Chromosome Results

POC genetic testing can identify chromosome causes of miscarriage. Learn how tissue is collected, why maternal contamination matters, how microarray results are read, and what comes next.

Products of conception genetic testing analyzes placental or fetal tissue from a miscarriage to determine whether a chromosome abnormality may explain the loss. The...

Recurrent Pregnancy Loss Genetic Test: Karyotype, Translocations, and Results

Understand recurrent pregnancy loss genetic testing, including miscarriage-tissue analysis, parental karyotypes, translocations, result meanings, and reproductive options.

Recurrent pregnancy loss genetic testing looks for chromosome findings that can explain why two or more pregnancies have ended and help estimate what may...

Second-Trimester Quad Screen Test: AFP, hCG, Estriol, Inhibin A, and Results

Learn how the second-trimester quad screen uses AFP, hCG, estriol, and inhibin A, what positive and negative results mean, and which follow-up tests may be offered.

The second-trimester quad screen is a maternal blood test that combines four pregnancy-related markers—alpha-fetoprotein (AFP), human chorionic gonadotropin (hCG), unconjugated estriol (uE3), and inhibin...

Sex Chromosome Aneuploidy Test: X and Y Chromosome Results

Understand sex chromosome aneuploidy testing for 45,X, XXY, XXX, XYY, and mosaic results, including prenatal screening accuracy, diagnostic confirmation, and clinical meaning.

A sex chromosome aneuploidy test looks for an unexpected number of X or Y chromosomes. Depending on the setting, it may be a prenatal...

Turner Syndrome Genetic Test: Monosomy X Screening, Diagnosis, and Results

Learn how Turner syndrome testing detects 45,X, mosaic, and structural X results, why cfDNA screening needs confirmation, and what diagnosis means before and after birth.

Turner syndrome genetic testing determines whether cells contain complete or partial loss of one sex chromosome in a person with a female phenotype. The...

Y-Chromosome Microdeletion Test: Male Infertility, AZF Regions, and Results

Understand Y-chromosome microdeletion testing for male infertility, including AZFa, AZFb, and AZFc results, sperm retrieval prognosis, ICSI inheritance, and next steps.

A Y-chromosome microdeletion test looks for missing DNA in the azoospermia factor, or AZF, regions of the Y chromosome. These regions contain genes needed...

Anticonvulsant Pharmacogenetic Test: HLA, CYP2C9, CYP2C19, and Results

Learn how HLA, CYP2C9, and CYP2C19 anticonvulsant pharmacogenetic test results may affect carbamazepine, phenytoin, clobazam, skin-reaction risk, dosing, and follow-up.

An anticonvulsant pharmacogenetic test looks for inherited variants that can affect the safety or handling of certain antiseizure medicines. The most clinically established findings...

BCHE Genetic Test: Pseudocholinesterase Deficiency, Anesthesia Risk, and Results

Understand how a BCHE genetic test, pseudocholinesterase activity, and dibucaine number reveal prolonged succinylcholine or mivacurium paralysis risk and guide safer anesthesia.

A BCHE genetic test looks for inherited changes that reduce the activity of butyrylcholinesterase, an enzyme also called pseudocholinesterase or plasma cholinesterase. Low or...

CACNA1S Genetic Test: Malignant Hyperthermia Risk and Results

Understand what CACNA1S genetic test results mean for malignant hyperthermia risk, trigger-free anesthesia, contracture testing, and family screening.

A CACNA1S genetic test looks for variants in a skeletal-muscle calcium-channel gene that can contribute to malignant hyperthermia susceptibility. Malignant hyperthermia is not an...

Chemotherapy Pharmacogenetic Test: DPYD, UGT1A1, TPMT, and Results

Learn how DPYD, UGT1A1, TPMT, and NUDT15 results can guide fluoropyrimidine, irinotecan, and thiopurine dosing and toxicity prevention.

A chemotherapy pharmacogenetic test can identify inherited differences that affect how a patient handles particular anticancer drugs, but no single result predicts response to...

COMT Genetic Test: Dopamine Metabolism, Pain, Medication Response, and Results

Understand COMT Val158Met results, dopamine metabolism, pain research, medication-response evidence, and why most COMT claims are not clinically actionable.

A COMT genetic test usually examines rs4680, also called Val158Met, a common variant that changes the activity of catechol-O-methyltransferase. This enzyme helps inactivate dopamine,...