Well, as I have posted, there are 24 known MTHFR variants and two that are most common in our population. C677T and A1298C are the most common variants but there are others and ones yet to be discovered. I am curious which variants everyone has.
Something interesting to note is: I recently discovered that here in Canada apparently genetics clinics only test for C677T variant as opposed to both common variants. When I asked why this was, I was told that it was not relevant to test for A1298C due to the proven health risks associated with C677T. Now, I don't buy this for one second and I think that this is a result of specific opinions of our countries doctors as opposed to the actual statistics and medical studies which prove differently.
1. C677T Heterozygous variant (one copy/allele)
2. C677T Homozygous variant (two copies/alleles)
3. A1298C Heterozygous variant (one copy/allele)
4. A1298C Homozygous (two copies/both alleles)
5. Compound variant heterozygous (more than one variant in one copy/allele)
6. Compound Homozygous (more than one variant in both coies/alleles)
7. Other variant not listed heterozygous (one copy/allele)
8. Other variant not listed homozygous (two copies/both alleles)
Just wanted to note, the one poll choice, "COMPOUND HOMOZYGOUS" doesn't exist and I accidentally put that in there when it should not be. (The dark blue option.)
The only compound situation that can occur can be COMPOUND HETEROZYGOUS, which means one allele has a mutated variant and the other allele has another. Each person's body is made up of pairs of genes. Each gene has two alleles. One copy that comes from one parent and one that comes from the other.
An example of this -
The most common COMPOUND Heterozygous situation: MTHFR having C677T and A1298C. Simply being Heterozygous means that you have one mutated copy of an allele which holds a particular variant and one normal allele.
Homozygous means you have two identical mutated copies of the same gene with the variant.
When you have two different types of variants (OR COMPOUND) since each gene has two copies, one from each parent, in Compound situations those pairs of genes or alleles will contain different variants - One will have one kind of variant and one will have another variant. Basically Compound situations mean that you host mutations in both alleles (both genes are abnormal) AND the mutations themselves are different from one another. This situation (Compound variants) is the same in terms of risk, health problem and treatments as a person who is Homozygous. In layman terms either situation means that both copies of your alleles are mutated, rather then heterozygous which means only one allele is abnormal.
The reality is, each person can be affected differently or suffer varying degrees of health related issues for which ever case they have. A person who has ONE abnormal gene with a variant (heterozygous) may or may not have symptoms that cause concern just as a person who has two abnormal genes with same or different variants may or may not.
While in the world of controversy with MTHFR (as to whether it is problematic or not to health or pregnancy) the debate goes even further when doctors debate whether to treat a person who is heterozygous or homozygous and Compound. If you struggle with getting treatments, it is very important to discover whether your health care system tests for all variants and not just one. Because some doctors do not know that Compound variants act in exactly the same way as Homozygous mutations they can miss the fact that you have two mutated alleles if they only test for one type of variant. This is exactly what happened to myself when I was tested for ONLY C677T. Doctors then proclaimed that I appeared to only be Heterozygous and with many doctors, they don't want to treat anyone who only has ONE mutation because they don't feel it is a risk to health as much as having TWO mutated genes. After demanding and suffering through the health care system, I did get a test for the other common variant A1298C and learned that I had that mutation as well. This changed the fact that I no longer only had ONE mutation but two, albeit two different ones. for my pregnancy THIS changed my treatment dramatically and if it wasn't learned it could have affected the way my pregnancy continued or not. I stress that if you are in the investigation stages of testing that you ensure you are prepared to educate your physician in case a situation like this arises. Regardless and either way, do not allow your physicians to minimize your diagnosis if you only have one mutation. If you have symptoms, the reality is that they need to be treated or at the very least not ignored.
In addition to anything I have mentioned, please keep in mind, that while I or others may have extensive knowledge in many areas, you should always seek professional medical advice from your own physician, as it pertains to medical conditions or concerns.
Good luck, and if you have any other questions that I can help you with, please feel free to message me directly.
MedHelp Genetics Community Leader;
Children - Special Needs Community Leader;
Down syndrome Community Leader & Ds Group Forum Founder/Moderator;
MTHFR Group Forum Founder/Moderator;
Pregnancy: June 2011 Community Leader
Hi, my name is sandy and my daughter is in her 3 trimester and they have been doing a lot of testing on her (her 2 previous pregnancy she had placenta abruption and had to deliver early but, thank goodness her in the babies were fine but, her last one had more complications). they have her on lovenox right now and has just past the week she had my grandson joe(2 pregnancy). the first time they took blood 12 vials they told her she had facto V Leiden then they took then they took 13 vials almost a month later they told her she had the MTHFR just a folic problem, mean while she is seeing a special from Dallas every week and they switch her regular on dr. and she has a level 2 ultra sound every week....last week after the ultras sound they said they were sorry they have to do it but there is a part 2 to the MTHFR and would have to draw blood again. Well she went for her ultra sound today and I had ask her to ask what is part 2 and she said that her MHTFR mutation is coming up C and probably is nothing, and then said that she would have to draw blood again something about they changed tubes so they were going to have to do it again....I guess I'm trying to figure out what's going on .....they say everything is good with the baby ....do you know why or what this second test is and why blood every week it seems.....would appreciate anything
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