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Date of last update: 10/12/2017.

Forum Name: Hematology Topics

Question: Testing question

 cjjtmeca - Thu Jul 05, 2007 10:00 pm

My sister and daughter both had some DNA testing done and the test indicate that they have mutations of C677T and A1298C. My sister is 45 and my daughter is 32. I am in the middle of getting the same DNA testing done. What does these mutations mean? Neither are on any kind of medication I am taking a small mg of Prozac daily. Thank you
 Dr. Chan Lowe - Thu Jul 05, 2007 10:23 pm

User avatar Both these genes are involved in the synthesis of methionine. They affect an enzyme called methylenetetrahydrofolate reductase (MTHFR).

These variants have been implicated in an increased rate of spontaneous abortions and sometimes lead to an increase in homocysteine levels which can cause an increased risk of clotting.

The C677T mutation creates a thermolabile form of the enzyme MTHFR that has decreased activity for converting homocysteine to methionine. The level of increased homocysteine with this mutation is variable and may or may not cause problems.

With both these mutations, having only a single gene with one normal copy generally only causes mild, if any problem. When both genes are abnormal, the effects are more pronounced.

The exact significance in regards to increased risk I am not familiar with.

You may want to talk with a geneticist to discuss the implications of these findings. I would also recommend that all of you have your homocysteine levels checked.

Best wishes.
 cjjtmeca - Fri Jul 06, 2007 1:23 pm

I want to thank you for the quick reply with my questions. I am trying to get an appointment with a Gene Dr and sit down with all three of our test and have him explain what that means to me. From what I understand my sister is at a age where she will not be able to take hormones due to blood clotting issues and my daughter each time becomes pregnant and will have to take predisone to carry the baby to tearm. She had tried invetro twice and both times she has lost the baby right away. Your explaination helps me understand why now. I am currently having blood vessel skin eurptions all over my body. I am being tested for Lupus but the test look negitive at this point. It looks like someone has taken a fork and scraped me all over when this happens. My skin whelps up and my blood pressure goes up. I am waiting for a appt. with a IM but in the mean time maybe I should see a Dr that deals with Hemalology issues due to the fact of these mutated gens. Thank you once more for you help.
Christal Janis
 cjjtmeca - Fri Jul 06, 2007 1:28 pm

In my first post I listed my sister and daughter each have a mutated gene. I neglected to mention that my sister has two copies of the C677T. In your reply to me you mentioned that one copy is usually not too much of a issue but what about having two copies does that double her risk? I am sorry for forgetting this important detail. Christal Janis

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