MTHF REDUCTASE MUTATION BY PCR

Code
900.2685
Name
MTHF REDUCTASE MUTATION BY PCR
Category
None
Department
Send-Out
Start Date
Expiration Date
Synonyms
MTHFR
CPT Codes
83890; 83896x4; 83898x2; 83912
Site
SBMF
Reference Test
36130
ATLAS Test Code

Specimen Information

Type

(2)Lavender, EDTA, WHOLE BLOOD

Volume

5.0 ml

Transport Info

Refrigerated

Fasting Required?
False
Patient Instructions

Reference Range

Negative for MTHFR C677T and A1298C mutations. The patient is negative for 2 MTHFR point mutations tested. Other causes of hyperhomocysteinemia, coronary heart disease, or thrombosis cannot be excluded.

Methodology

Real-Time Fluorescence Polymerase Chain Reaction (PCR)

Clinical Significance

Identification of genetic etiology for persistent hyperhomocysteinemia. Assess risk of venous thrombosis. With other genetic thrombophilic factors (factor V Leiden or prothrombin G20210A), detection of MTHFR mutations indicates significantly increased risk for venous thrombosis.

Hyperhomocysteinemia is a widely recognized risk factor for coronary artery disease, venous thrombosis, and stroke. It is also involved in the pathogenesis of neural tube defects, stillbirths, and recurrent pregnancy loss. Methylenetetrahydrofolate reductase (MTHFR) is a key enzyme in the metabolism of homocysteine. This enzyme catalyzes the reduction of 5,10-methylenetetrahydrofolate to 5-methyltetrahydrofolate, which is the major circulating form of folate. Folate is a cofactor in re-methylation of homocysteine. MTHFR gene can be silenced by point mutations. This can result in low folate and increased plasma levels of homocysteine. C677T is commonly seen in Caucasians of European descent. The frequency of homozygotes for this mutation ranges from <5 to 20 percent based on population studied. Based on limited data, the frequency of A1298C homozygotes is estimated to be 9% and the frequency of C677T/A1298C heterozygotes is estimated to be 15 to 20 percent. Both C677T and A1298C alleles are found to decrease MTHFR enzyme activity. Only C677T homozygotes and C677T/A1298C heterozygotes are associated with increased plasma homocysteine levels.

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