- Patient Preparation
- Lavender (EDTA), pink (K2EDTA), or yellow (ACD Solution A or B).
- Specimen Preparation
- Transport 3 mL whole blood. (Min: 1 mL)
- Storage/Transport Temperature
- Unacceptable Conditions
- Ambient: 72 hours; Refrigerated: 1 week; Frozen: Unacceptable
Negative: Neither of the common MTHFR gene mutations tested, c.665C>T and c.1286A>C, were detected. Other causes of elevated homocysteine levels, coronary heart disease, or thrombosis were not assessed. This genotype is associated with a normal folate metabolism.
Characteristics:Mutations in the MTHFR gene (c.665C>T and c.1286A>C) correlate with reduced enzyme activity; however, only homozygotes for c.665C>T or compound heterozygotes for c.665C>T/c.1286A>C have significantly elevated plasma homocysteine levels and an increased risk for premature cardiovascular disease. These individuals may also show toxicity from medications (ie, methotrexate) that affect folate metabolism.
Incidence:The allele frequency of c.665C>T is 0.35 in European Caucasians and 0.12 in African Americans. The allele frequency of c.1286A>C is 0.31 in European Caucasians and 0.15 in African Americans.
Inheritance: Autosomal recessive.
Cause: Homozygosity for MTHFR gene mutation c.665C>T or compound heterozygosity for c.665C>T/c.1286A>C.
Mutations Tested: c.665C>T (previously c.677C>T); p.Ala222Val and c.1286A>C (previously c.1298A>C); p.Glu429Ala.
Clinical Sensitivity: Undefined. Sensitivity is dependent upon multiple contributing factors.
Methodology: PCR followed by fluorescent monitoring using hybridization probes.
Analytical Sensitivity & Specificity: 99 percent.
Limitations:Only the two MTHFR gene mutations (c.665C>T and c.1286A>C) will be targeted. Diagnostic errors can occur due to rare sequence variations.
This test is performed pursuant to an agreement with Roche Molecular Systems, Inc.
This test is performed pursuant to an agreement with Siemens Medical Solutions.
See Compliance Statement C: www.aruplab.com/CS
Counseling and informed consent are recommended for genetic testing. Consent forms are available online.
|Component Test Code*||Component Chart Name||LOINC|
|0055657||MTHFR Mutation: C665T||28005-7|
|0055658||MTHFR Mutation: A1286C||28060-2|
|2001331||MTHFR PCR Specimen||31208-2|
- Hyperhomocystinemia, C677T and A1298C Mutations
- MTHFR DNA assay