Test No Longer Available
METHYLENETETRAHYDROFOLATE REDUCTASE (MTHFR) THERMOLABILE VARIANT, DISCONTINUED - (B)
Test Code: MD
Date: June 17, 2015
To: Ordering Physicians (MTHFR test)
From: Dr. Beth Spriggs and Dr. Ronald Agatep, DSM Molecular Diagnostic Laboratory, Health Sciences Centre, Room MS573, 820 Sherbrook St.
Subject: Discontinuation of Methylenetetrahydrofolate Reductase (MTHFR) Thermolabile Variant Test
Effective July 15, 2015, the DSM Molecular Diagnostic Laboratory will discontinue the test for the methylenetetrahydrofolate reductase (MTHFR) thermolabile variant, C677T. This decision is based on the American College of Medical Genetics and Genomics (ACMG) practice guideline*, where testing for the MTHFR variant is no longer recommended in the evaluation of a patient with venous thrombosis. This ACMG guideline is consistent with statements from the American Congress of Obstetricians and Gynecologists, the British Committee for Standards in Hematology, and the British Society for Haematology.
Although the presence of the MTHFR thermolabile variant, C667T, in a homozygous state may contribute to mild hyperhomocysteinemia, this variant is only one of many risk factors contributing to venous thrombosis. In addition, fortification of cereal products with folic acid is mandated in Canada and this has resulted in increased serum folate concentrations and corresponding lowered serum total homocysteine levels across the population. This dietary change appears to have further diminished the association between the presence of the thermolabile variant and homocysteine levels.
This test will be discontinued effective July 15, 2015. Please contact either molecular geneticist before this date if you have any concerns.
Elizabeth Spriggs, PhD, FCCMG at email: email@example.com
Ronald Agatep, PhD, FCCMG at ph: 204-787-2845 or email: firstname.lastname@example.org
*http://www.ncbi.nlm.nih.gov/pubmed/23288205 Hickey et al., 2013. ACMG Practice Guideline: lack of evidence for MTHFR polymorphism testing. Genet Med 15:153-156.