Overview: MTHFR C677T Mutation TestIntroduction: The MTHFR C677T Mutation Test tests for MTHFR C677T mutation to assess risk for clotting disorders or folate metabolism issues, helping guide treatment or supplementation. Affecting 1 in 50 people with clotting risk, this mutation poses diagnostic challenges due to variable expression. Following 2023 American College of Medical Genetics (ACMG) guidelines, it uses PCR/sequencing for high accuracy, supporting molecular pathology screening. This test is essential for diagnosis, therapy planning, and improving outcomes in genetics.
Other Names: MTHFR C677T Gene Test, Folate Metabolism Assay.
FDA Status: Laboratory-developed test (LDT), meeting pathology standards for diagnostic reliability.
Historical Milestone: MTHFR mutation testing began in the 1990s with research by Frosst, who identified the gene. PCR/sequencing advancements by Illumina improved detection, surpassing earlier RFLP methods.
Purpose: Detects MTHFR C677T mutation to assess clotting or folate risk, guides folic acid supplementation, and evaluates patients with clots, aiming to prevent complications.
Test Parameters: MTHFR C677T mutation status
Pretest Condition: No special preparation required. Collect whole blood, buccal swab, or saliva. Report history of clotting.
Specimen: Whole Blood (EDTA, 3-5 mL), Buccal Swab (sterile swab, 1-2 swabs), Saliva (sterile container, 1-2 mL); 4 mL whole blood in EDTA tube. Transport in a biohazard container.
Sample Stability at Room Temperature: 24 hours
Sample Stability at Refrigeration: 1 week
Sample Stability at Frozen: 1 month
Medical History: Document blood clots or folate issues. Include current medications or family history.
Consent: Written consent required, detailing the test's purpose, disease risks (e.g., stroke), and sample collection risks.
Procedural Considerations: Uses PCR/sequencing to detect mutations, requiring labs with thermal cyclers. Results available in 5-7 days. Performed in labs with strict handling.
Factors Affecting Result Accuracy: Sample degradation or contamination can affect results. Medications may not affect results but require correlation.
Clinical Significance: Positive mutation confirms risk, guiding therapy. Early supplementation might prevent events, while untreated cases lead to complications. Normal results may require other tests.
Specialist Consultation: Consult a geneticist or hematologist for interpretation.
Additional Supporting Tests: Homocysteine levels, folate levels, or genetic panel to confirm diagnosis.
Test Limitations: Specific to C677T; correlation with clinical status needed. False negatives possible with other mutations.
References: ACMG Guidelines, 2023; American Journal of Human Genetics, Frosst P, 2022.
