I’ve been wondering for some time whether my factor V leiden related DVT could be connected to my food chemical intolerance. I came across this very interesting page that connects hyperhomocysteinemia caused by methylhydrotetrafolate reductase (MTHFR) mutations and cystathione beta synthase (CBS) polymorphisms to blood clotting. I had no idea the MTHFR mutation was so common:
Studies looking at the prevalence of homozygosity (both (2) copies of the gene are mutated) for the thermolabile variant mutation in MTHFR have shown a prevalence near 15% in European, Middle Eastern and Japanese populations, compared with a range at or below 1.4% in African Americans. Patients who are heterozygous (1 copy of the mutated gene) are seen in 30-40% of the population.
Heterozygosity for the CBS mutation is thought to occur in .4% to 1.4% of the population. Homozygosity for the CBS mutation is quite rare.
The risk factors for DVTs tend to multiply one another. They don’t have a combined risk factor listed for hyperhomocysteinemia, oral contraceptives, and heterozygous factor V leiden, but I bet it is pretty darn high. My sister also recently got a DVT – she has the same heterozygous FVL gene, she was smoking (naughty girl), and she got it within *a month* of being given the third generation pill, which seems suspiciously fast. To connect the dots, smoking also raises homocysteine levels.
I don’t know whether they test for high homocysteine on the standard clot risk tests in the UK. But I think I should get myself tested. Wonder if I could be an individual who has struck it particularly lucky with an MAO mutation (30% of popn), a MTHFR mutation (30% of popn), an SUOX mutation (also a hefty chunk of the popn), a leukotriene production mutation (no idea of frequency), oh, and FVL too (5-20% of popn). Because that would explain a lot. And it probably wouldn’t even be that rare.