When another frozen embryo cycle with an A grade embryo and Natural Killer (NK) Cell protocol didn’t work my Doctor suggested we try one more genetic test. Its was a test to see if we shared a match on a gene called DQ Alpha (DQa).
Despite originating from opposite sides of the planet, the tests came back confirming a match.
Seems that even when it comes to genetics it is a small world!!
So What Is DQa and How Does It Impact TTC?
The DQa gene sits on chromosome 6. Part of our immune system one of its key roles is helping the body identify and prevent foreign antigens from attacking and making us sick.
When it comes to DQa we each get a representation from our mother and from our father. These are represented in numbers - eg 1.02, 1.01, 05.05.
Having a genetic match for DQa actually doesn’t impact the health of your embryo or baby.
Instead a match impacts the connection between the paternal DNA contribution (sperm) and the maternal body (uterus).
Normally something in the sperm’s DNA sends a signal to the uterus that this foreign body (embryo) is ok, allowing it to implant.
In the case where the male DNA contribution of the embryo shares the same DQa gene as the mother this message is thwarted.
The uterus then fails to recognise the embryo as a separate body, instead seeing it as its own “self”. The immune system kicks in with NK cells to eliminate the embryo as it views it a risk.
In layman's terms - owing to one number, on one chromosome, my body systematically attacks and rejects our healthy embryos as it can’t tell the difference between my own DNA and my husbands!!
My understanding is that DQa can be the cause of:
- Recurrent miscarriage
- Failure to implant
- The activation of NK cells in the uterus (in response to repeated implantation of DQa embryos)
- Secondary Infertility (in response to a DQa pregnancy making it full term causing a build up of NK cells)
In this combination one of the female and one of the male partners DQa numbers match. It does not matter what the numbers are - only that they are the same. Eg Female 1.02, 1.01 Male 1.02 05.05
In this scenario 50% of your embryos will carry the matching DQa gene.
This can be represented in two ways:
- The male and female have two individual numbers and both sets match - eg Female - 1.02, 1.01 Male 1.02, 1.01
- The male has two of the same DQa genes and they match one of the females numbers eg female 1.01, 1.02; Male 1.02 1.02.
In a complete match 100% of your embryos will carry the matching DQa gene.
A 100% match often means your road to pregnancy will be limited. We were told if this was the case for us then our best options moving forward would be:
- Donor sperm
- Surrogacy using our embryos
- Donor Embryos
Thankfully our match is a partial one. The options are a little more open.
50% of our embryos will not share this match, and therefore it will not be an issue for them to implant. However, as you can’t screen the embryos for this it becomes a bit like pot luck!
Our options presented were as for the 100% match, and additionally the option to undertake increased immune system treatments to help desensitise me to my hubby’s DNA.
- NK Cell Protocol
- IVIG Blood plasma transfusions
- Lymphocyte Immunisation Therapy (LIT)
- Only transferring one embryo - making it less of a risk of losing both if one is DQa and the other is not.
LIT works like an allergy treatment by injecting the woman with white blood cells from her partner over a period of time until her immune system is desensitised to it and no longer reacts.
- If you have had repeated failed cycles or miscarriages despite the NK cell treatment it may be worth getting tested for a DQa match
- Find a Doctor who specialises in immunologic causes for infertility - Similar to the NK Cell treatment only some Doctors are offering this treatment.
- At this stage of things the treatment is getting quite invasive and expensive. Take the time to consider carefully how you feel about the treatment rather than just blindly moving forward. Do your own research. Consider what options are right for you.
Dr Sher in the US has a good website about immune-related causes for infertility and discusses DQa.
Do you have a DQa match with your partner? What did you decide to do? How did the treatment work for you?