Genetics
Genetic testing analyzes DNA to identify variants—either inherited or acquired—that influence how the body functions, processes nutrients, and responds to disease. Unlike standard blood tests that measure substances circulating in the body, genetic tests examine the underlying molecular code that can predispose a person to certain conditions, affect how medications or nutrients are metabolized, or directly drive disease.
HealthMatters tracks both inherited genetic variants—present from birth and passed through families—and acquired (somatic) mutations, which develop over time in specific cell populations and are not inherited.
What this category includes
Methylation and nutrient metabolism variants
Variants in genes such as MTHFR can affect how the body processes folate and regulates homocysteine levels. These inherited single nucleotide polymorphisms (SNPs) are associated with differences in cardiovascular risk, methylation efficiency, and B vitamin metabolism. Common variants include C677T and A1298C.
Molecular mutation testing
Acquired mutations in genes such as JAK2 are linked to specific diseases, particularly blood disorders. For example, JAK2 mutations are strongly associated with Polycythemia Vera and other myeloproliferative neoplasms. These tests use PCR-based or sequencing methods to detect mutations in blood or bone marrow cells and are used for diagnosis and disease classification—not hereditary screening.
How to interpret genetic results
Genetic test results use terminology that differs from standard lab testing:
- Detected / Not Detected — Used for mutation testing to indicate whether a specific genetic change is present
- Homozygous / Heterozygous — Used for inherited variants; homozygous means both gene copies carry the variant, heterozygous means one copy does
- Variant / Wild-type — Variant indicates a change from the reference sequence; wild-type indicates the typical (non-mutated) sequence
A detected or variant result does not always mean disease is present. Interpretation depends on clinical context, symptoms, and related laboratory findings.
Related biomarkers
Genetic results are most meaningful when interpreted alongside functional biomarkers. For example:
- MTHFR variants alongside homocysteine levels
- JAK2 mutation results alongside complete blood count (CBC), hemoglobin, hematocrit, and erythropoietin
Tracking both genetic and functional data over time provides a more complete and actionable view of health than either in isolation.
Biomarkers in this category
5 biomarkers · optimal ranges shown
JAK2 Exon 12 mutation detected in blood
Reduced methylenetetrahydrofolate reductase (MTHFR) enzyme activity is a genetic risk factor for hyperhomocysteinemia, especially when present with low serum folate levels. Two common variants in the MTHFR gene result in reduced enzyme activity. The "thermolabile" variant C677T and A1298C occur frequently in the general population. Mild to moderate hyperhomocysteinemia has been identified as a risk factor for coronary artery disease and venous thromboembolism. Hyperhomocysteinemia is multifactorial, involving a combination of genetic, physiologic and environmental factors. Recent studies do not support the previously described association of increased risk for coronary artery disease and venous thromboembolism with mild hyperhomocysteinemia caused by reduced MTHFR activity. Therefore, the utility of MTHFR variant testing is uncertain and is not recommended by The American College of Medical Genetics and Genomics (ACMG) or the American Congress of Obstetricians and Gynecologists (ACOG) in the evaluation of venous thromboembolism or adverse pregnancy outcome. Modest positive association has also been found between the "thermolabile" variant of the MTHFR gene and many other medical complications, such as recurrent pregnancy loss, risk of offspring with neural tube defects, neuropsychiatric disease, and chemotherapy toxicity. Increased risk of coronary artery disease, venous thromboembolism and increased plasma homocysteine can be caused by a variety of genetic and non-genetic factors not screened for by this assay. If indicated by personal or family history of thromboembolism, consider additional testing such as plasma homocysteine levels, factor V Leiden and prothrombin gene mutations. The C677T and A1298C variants are detected by amplification of the selected regions of the MTHFR gene by polymerase chain reaction (PCR) and fluorescent probes hybridization to the targeted regions, followed by melting curve analysis with a real time PCR system. Although rare, false positive or false negative results may occur. All results should be interpreted in context of clinical findings, relevant history, and other laboratory data.
AKA: The methylenetetrahydrofolate reductase gene / MTHFR gene The MTHFR gene codes for an enzyme that is an important part of the methylation cycle. What is the methylation cycle? The MTHFR gene codes for an enzyme that is an important part of the methylation cycle. Methylation is the adding and removing of a methyl group (CH3) to amino acids, DNA, and other enzymes or proteins. Methylation can turn on and off genes, maintain and repair your DNA, and alter proteins. rs1801133 - G/G: typical - A/G: one copy of MTHFR C677T allele (heterozygous), decreased by 40% - A/A: two copies of MTHFR C677T (homozygous), decreased by 70 – 80% rs1801131 - T/T: typical - G/T: one copy of MTHFR A1298C (heterozygous), slightly decreased enzyme function - G/G: two copies of MTHFR A1298C (homozygous), decreased enzyme by about 20%
rs1801131 is a SNP in the MTHFR gene