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Gene

MTHFR

methylenetetrahydrofolate reductase

Summary

Cytogenetic location
1p36.22
Coordinates
Chromosome 1: 11,785,723–11,805,964 (GRCh38)
Exons
12 exons across 20.2 kb
Protein
656 amino acids
Inheritance
Autosomal recessive
MANE Select transcript
ENST00000376590.9NM_005957.5
Locus type
gene with protein product
  • Very high
  • Confident
  • Low
  • Very low

Reference genomeGRCh38

Positions on gene and variant pages follow this choice, in this browser.

Curated report relevant to this gene

  • Homocystinuria & Cobalamin Disorders

    • HomocystinuriaAutosomal recessive

      Includes classic homocystinuria due to CBS deficiency, severe MTHFR deficiency and the combined and remethylation cobalamin disorders, which can cause lens dislocation, blood clots, skeletal changes, anaemia and developmental problems.

      • ClinGen rates the link definitive
      • 5 GenCC submitters rate it definitive or strong
      What knowing changes

      Knowing allows treatment with vitamin B6, B12, folate, betaine and diet as appropriate, which can prevent lens dislocation, thrombosis and other complications.

Inheritance

Autosomal recessive
It takes a changed copy from each parent. With one, you are a carrier and usually unaffected; when both parents are carriers, each child has a one-in-four chance of inheriting two.

Trait report that reads MTHFR

How MTHFR is laid out

  • Coding sequence
  • Untranslated region
  • Intron
  • Direction of transcription
  • Known disease-causing sites
  • Stretches short reads find hard
Chromosome 1, with a bracket where MTHFR sits. MTHFR and 19 genes near it on chromosome 1, from 11,295,844 to 12,295,843.Chromosome 11p36.22p36.33p36.32p36.31p36.23p36.22p36.21p36.13p36.12p36.11p35.3p35.2p35.1p34.3p34.2p34.1p33p32.3p32.2p32.1p31.3p31.2p31.1p22.3p22.2p22.1p21.3p21.2p21.1p13.3p13.2p13.1p12p11.2p11.1q11q12q21.1q21.2q21.3q22q23.1q23.2q23.3q24.1q24.2q24.3q25.1q25.2q25.3q31.1q31.2q31.3q32.1q32.2q32.3q41q42.11q42.12q42.13q42.2q42.3q43q4411.4 Mb11.6 Mb11.8 Mb12 Mb12.2 MbUBIAD1: 11,273,189–11,297,104, forward strandUBIAD1DISP3: 11,478,905–11,537,583, forward strandDISP3FBXO2: 11,637,018–11,655,785, reverse strandFBXO2FBXO44: 11,650,618–11,663,327, forward strandFBXO44MAD2L2: 11,657,230–11,692,605, reverse strandMAD2L2FBXO6: 11,664,141–11,674,354, forward strandFBXO6DRAXIN: 11,690,958–11,725,857, forward strandDRAXINAGTRAP: 11,736,070–11,754,802, forward strandAGTRAPC1orf167: 11,761,787–11,789,585, forward strandC1orf167MTHFR: 11,785,723–11,805,964, reverse strandMTHFRCLCN6: 11,806,096–11,848,080, forward strandCLCN6NPPA: 11,845,701–11,848,345, reverse strandNPPANPPB: 11,857,454–11,859,648, reverse strandNPPBKIAA2013: 11,919,590–11,926,428, reverse strandKIAA2013PLOD1: 11,934,205–11,975,542, forward strandPLOD1MFN2: 11,980,181–12,015,211, forward strandMFN2MIIP: 12,019,466–12,032,048, forward strandMIIPTNFRSF8: 12,063,079–12,144,221, forward strandTNFRSF8TNFRSF1B: 12,166,970–12,209,228, forward strandTNFRSF1BVPS13D: 12,230,007–12,512,047, forward strandVPS13DDiagram of MTHFR: 12 exons on the reverse strand of chromosome 1Exon 12: 9 known disease-causing sitesExon 11: 13 known disease-causing sitesExon 10: 9 known disease-causing sitesExon 9: 13 known disease-causing sitesExon 8: 16 known disease-causing sitesExon 7: 18 known disease-causing sitesExon 6: 23 known disease-causing sitesExon 5: 13 known disease-causing sitesExon 4: 9 known disease-causing sitesExon 3: 15 known disease-causing sitesExon 2: 17 known disease-causing sitesExon 12: 11,785,723–11,790,898, 5,176 basesExon 11: 11,791,207–11,791,326, 120 basesExon 10: 11,792,278–11,792,379, 102 basesExon 9: 11,793,907–11,794,089, 183 basesExon 8: 11,794,358–11,794,538, 181 basesExon 7: 11,794,729–11,794,863, 135 basesExon 6: 11,795,098–11,795,348, 251 basesExon 5: 11,796,206–11,796,399, 194 basesExon 4: 11,800,212–11,800,322, 111 basesExon 3: 11,801,161–11,801,399, 239 basesExon 2: 11,802,881–11,803,129, 249 basesExon 1: 11,805,888–11,805,964, 77 bases1211109876543215′3′

Exons of the gene's MANE Select transcript (release v1.5), from NCBI and EMBL-EBI, on the GRCh38 reference genome.

Chromosome bands from UCSC's GRCh38 ideogram (2022-10-29).

Nearby genes from Ensembl release 116, on GRCh38.

Exons make up 7 kb of the gene's 20.2 kb; 1,971 of those bases code for the protein.

How a genome test reads MTHFR

183

positions in MTHFR where ClinVar classes a change as pathogenic or likely pathogenic

None of them falls in a region short reads find hard.

A whole genome covers all 20.2 kb of MTHFR, introns included, not only the 7 kb of exons.

Where this comes from

  • HGNC: the gene's symbol, name, other symbols and location.
  • MANE Select v1.5, from NCBI and EMBL-EBI: the transcript, its exons and coding sequence.
  • GenCC and ClinGen, released 2026-10-16: which conditions the gene is linked to, and how strongly.
  • The ACMG secondary findings list, SF v3.2.
  • ClinVar and the GIAB stratifications: known disease-causing sites, and the regions short reads find hard.
  • The Human Phenotype Ontology, release 2026-09-01: the traits linked to the gene. Find out more at hpo.jax.org.
  • Data release 2026.10.16-c6eea6bf.

Cite this page

APA

Dante Labs. (n.d.). MTHFR gene: methylenetetrahydrofolate reductase. Retrieved 16 October 2026, from https://dantelabs.com/genes/mthfr

Vancouver

Dante Labs. MTHFR gene: methylenetetrahydrofolate reductase [Internet]. [cited 16 October 2026]. Available from: https://dantelabs.com/genes/mthfr

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