• Turnaround time:
    10–21 calendar days (14 days on average)
  • Preferred specimen:
    3mL whole blood in a purple-top tube
  • Alternate specimens:
    DNA or saliva/assisted saliva
  • Sample requirements
  • Request a sample kit


Associated disorders

The MTHFR gene is associated with autosomal recessive MTHFR deficiency (MedGen UID: 383829).

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Invitae tests that include this gene:

The MTHFR gene is the only known gene associated with MTHFR deficiency.

The NM_005957.4:c.665C>T (p.Ala222Val) (aka 677C>T) and c.1286A>C (p.Glu429Ala) (aka 1298A>C) variants are not reported in our Primary report as they are classified as Benign. If present, these variants would be listed in our Supplemental report, which is available upon request.

Additionally, the following medical organizations recommend against testing for these common variants:

  • American College of Medical Genetics PMID: 23288205
  • American Congress of Obstetricians and Gynecologists PMID: 23963422
  • The British Committee for Standards in Haematology and the British Society for Haematology PMID: 20128794

The MTHFR gene encodes the methylenetetrahydrofolate reductase protein. This protein is involved in the remethylation of homocystein to methionine.

Assay and technical information

Invitae is a College of American Pathologists (CAP)-accredited and Clinical Laboratory Improvement Amendments (CLIA)-certified clinical diagnostic laboratory performing full-gene sequencing and deletion/duplication analysis using next-generation sequencing technology (NGS).

Our sequence analysis covers clinically important regions of each gene, including coding exons, +/- 10 base pairs of adjacent intronic sequence in the transcript listed below. In addition, analysis covers the select non-coding variants specifically defined in the table below. Any variants that fall outside these regions are not analyzed. Any specific limitations in the analysis of these genes are also listed in the table below.

Our analysis detects most intragenic deletions and duplications at single exon resolution. However, in rare situations, single-exon copy number events may not be analyzed due to inherent sequence properties or isolated reduction in data quality. If you are requesting the detection of a specific single-exon copy number variation, please contact Client Services before placing your order.

Gene Transcript reference Sequencing analysis Deletion/Duplication analysis
MTHFR NM_005957.4