New Thyroid Genetic and Blood Tests

One of the most common things I get asked about is thyroid issues. A person can be hypothyroid (underactive) or hyperthyroid (overactive). So far, so easy.

The difficulties come in testing the thyroid because, as we know, the vast majority of mainstream doctors will test the TSH and T4 levels, including an autoimmune antibody if you are lucky. If a result happens to show on that, happy days. More often than not, though, the result looks fine and off you pop, having been told your problem is not with your thyroid.

The truth of the matter is that is just not enough information to get a good look at what’s going on with the thyroid. After a time, people with that ‘all-is-OK’ diagnosis start wondering if they should look a bit deeper – and end up at my or another functional medicine practitioner’s door.

The first thing I do in that case, if the symptoms seem to fit and, importantly, the person’s instinct is that their thyroid is involved somehow – remember you know your body better than anybody else! – is ask them to do a simple basal temperature test. If that’s positive, we then do a full thyroid screen looking at all of the markers involved. We’re looking for how much of the active T3 there is, or are you converting your T4 into the inactive Reverse T3? Is there a lack of the co-factors such as iodine or selenium to do the necessary conversions, what autoimmune antibodies are present yada, yada, yada.

You can read a lot more about testing the thyroid on my Thyroid Factsheet here. 

But why?

I am very often asked: why do I have a problem with this or that to do with thyroid function? Or indeed, if someone is on thyroxine from the doctor, why are they not feeling any better? It could be any number of things and this graphic is a good reminder of some of the things that can go wrong – namely: nutrient levels, high cortisol, inflammation and genetic variants:


Thyroid disruptors


Note the genetic variants issue there. Up to now, I have been checking the nutrients, cortisol and inflammation levels with thyroid people, but now it is time to add on the genetic info, which I think will be useful especially for people whose thyroid is not correcting with the usual treatment.

Thyroid Genetics

I have been doing the DI02 Thyroid test for quite some time – this often shows why a person is not responding so well to thyroxine treatment: because they have a particular fault on the gene that controls the delivery of T3 to the brain, so they need T3 treatment with their T4.  Quite a few people have had that test done and had an ‘Aha’ moment, taken their results to their GP and been started on T3 – often as a trial as the Doctor is not usually au fait with the D102 – but it has worked.

However it can be a bit more complex than that and there has been a lot of new research on this over the past five years or so with quite a few other genes found to impact on thyroid function as well as D102. Here’s a pretty technical article for those of you who want to read more about it.

To help, here is a rundown of the key genes that could be involved:

Thyroid genes


So, I have listed several new tests here  to help with the genetic side of things.

First, a VX Thyroid Gen panel which covers the main genes involved as above. The gene panel investigates:

  • Pituitary receptivity to TRH
  • Thyroid receptivity to TSH
  • Thyroid receptivity to TSH signalling
  • Conversion of T4 to T3
  • Clearance of rT3 from circulation
  • Stress response and effect on thyroid function
  • Detoxification of compounds impacting thyroid hormone levels
  • Susceptibility to inflammation and infection, both of which affect thyroid function

Genes included:

  • TRHR: responsible for regulating the body’s receptivity to TRH which stimulates the pituitary to secrete TSH
  • TSHR: plays a central role in thyroid hormone metabolism by controlling the body’s receptivity to TSH
  • PDE8B: involved in the body’s receptivity to TSH signalling
  • DIO1 & DIO2: regulate the conversion of T4 to T3 and the clearing of rT3 from circulation
  • COMT: one of the main pathways for clearing compounds that impact thyroid hormone levels
  • FKBP5: involved in the body’s response to stress which affects thyroid hormone levels
  • TNF-alpha: impacts the body’s susceptibility to inflammation which has an affect on thyroid function
Sample Needed:
  • 1 x simple buccal (cheek) swab. Return envelope provided

You can do this Thyroid Gen test on its own, which is a simple cheek swab. Or, you can add the thyroid blood markers as the Thyroid Pro. I like this as it includes all the usual thyroid markers including the autoimmune antibodies as well as Reverse T3, serum and red cell folate, serum and active B12, plus ferritin, Vitamin D and an inflammation CRP check.

Even better, you can also add an adrenal test to this as the Thyroid Elite. That includes six salivary cortisol measurements rather than the usual four, plus DHEA-s, testosterone and oestrogen.

Both the Thyroid Pro and Elite tests are blood tests and include a phlebotomy home visit in the price, which makes life nice and easy for a change!

How will it help practically?

All the tests come with a report telling you what issues your genes might suggest and what to do about them if you suspect they have been triggered. Remember, just because you have a weakness or SNP on a gene, doesn’t mean you develop the problem, but sometimes you can see a clear reason why your thyroid is messing about or not responding to treatment, and that can be crucial information.

Are you susceptible to high cortisol or inflammation which will impact it and need to do more to keep those dampened down? Are you a person who needs more of the co-factors for certain pathways to offset a possible weakness? Do you need a higher than normal dose of meds or boosters because your TSH signalling is not quite right? If you put T3 with your T4 treatment, would it give your thyroid the boost it needs and stop side-effects?

See? Important info.

You can see sample reports for each element here: thyroid genethyroid blood markersadrenal markers

So, with these new tests, you can now cover most of those thyroid disruptors, certainly the genetic info, all the usual thyroid markers, high cortisol, inflammation, lack of Vitamin D, folate and B12 – and have a home visit for the blood to be taken in with the price – I’d say that’s a good test! If you throw in a vitamin and mineral test to check the nutrients needed for thyroid function too, that would be a really comprehensive check.

I hope it helps.




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