Test Directory
MTHFR (A1298C) Mutation
Justification
This variant does not cause hyperhomocysteinemia on its own, but individuals with combined heterozygosity with C677T have similar levels to those homozygous for C677T. This variant is very common in the population, with an allele frequency ranging from 13 to 40% depending on the population.
STAT: < 48 hours (M-F)
RT-PCR
Draw Tube: Purple Top
Sample Type: EDTA Whole Blood
Specimen Requirements
Sample Type | Volume Required | Minimum Volume | Stability | |
---|---|---|---|---|
PREFERRED | EDTA Whole Blood | 3mL | 1mL | Room Temp.: 1 month Refrigerated: 1 month |
ALTERNATIVE | Cheek swab | 2 swab | - | Room Temp.: 1 month Refrigerated: 1 month |
REJECTION CRITERIA | Sample contamination; sample compromised |
SPECIAL INSTRUCTIONS | - |
General Information
METHODOLOGY | RT-PCR |
STAT TAT | < 48 hours (M-F) |
STAT TAT Performance | > 90% of results released in 48 hours |
ROUTINE TAT | < 1 week |
ALTERNATIVE NAMES | c.1286A>C, p.Glu429Ala |
DESCRIPTION | This test detects the A1298C variant (c.1286A>C, p.Glu429Ala) using real-time PCR. This test can detect whether a patient is normal or has one A1298C allele (i.e., heterozygous) or two alleles (i.e., homozygous). |
LIMITATIONS | Rare variants within the primer binding sites could lead to allele drop-out and a potential false negative result. Rare, pathogenic variants in MTHFR can cause an autosomal recessive inborn error of metabolism with developmental delay, eye disorders, thrombosis and osteoporosis. To detect these variants, full gene sequencing should be ordered. |
NORMAL RANGE | No mutation found |
ASSOCIATED TESTING | - |
REFERENCES | Hickey S.E., Curry C.J., Toriello H.V. ACMG Practice Guideline: lack of evidence for MTHFR polymorphism testing. Genet Med. 2013;15(2):153–6. |
SAMPLE REPORT | Upon request |
NEW YORK STATE APPROVED | No |
Test Codes
ORDER CODE | P3080 |
CPT CODE | 81291 |
LOINC CODE | 28060-2 |