Family and Caregiver Schizophrenia Discussion Forum

Genetic testing for medication

I spoke with my sons Dr today and since he has had trouble with side effects on several of the meds he has been put on, he recommended that he try this. It will give the Dr. an idea of what he can and can’t metabolize and it will also show if he has The MTHFR ( Folic Acid) gene mutation

He also said that Medicare and Medicaid covers this.

I spoke to my psychiatrist about this today. His opinion after about 250 samples he went through in his practice was the results were uneven at best. I know everyone is searching for that magic bullet, but he gave up on testing when he observed that all too often patients who were stable on one medication yet results showed they were supposedly in the ‘red’ unrecommended zone, while drugs that already failed them were in ‘green’ recommended or ‘yellow’ may not work categories. Similar inconsistencies are found in comparing genetic origin tests from multiple vendors.

Granted these tests are improving all the time, but qualitative tests are not the sure thing that genetic identification or marker tests are. His thoughts were the tests were of dubious value and were being oversold and marketed beyond their capabilities. But this is a sample of one and I’ve been stable on my medication for years. I just happened to ask as I often do when these things come up on the forum to get my $270 an hour’s worth out of our sessions. YMMV.

Edit: he did see value in marker tests for folic acid metabolism if there were concerns, his issue was with tests that tried to recommend or discourage prescribing specific drugs.

Yes, he told me almost the same thing regarding the results. He said the psychiatric community at first was very excited about this testing when it first came out but soon found that it wasn’t as specific as "cell’ genetic testing and results do vary. I think we’re still going to have it done. It will at least tell us what he does or doesn’t have regarding the mutation.

Thank you for taking the time to talk to your Dr. about this. I think it’s so important to know what Drs. are doing or not doing for patients and I think sharing that information only helps us be more educated as patients and caregivers.

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I looked into the research literature last time the topic came up, and the consensus right now is that the genetic tests don’t offer anything above and beyond what you’d get from a knowledge of the basic pharmacokinetics of the medication (which a psychiatrist should get in their training). So your doctor’s take is consistent with the literature.

I believe genetic testing on how drugs are metabolized is well established. There are four major pathways. Here is what the FDA says about aripiprazole and dosing if one is a poor metabolizer on CYP2D6.

The metabolism and elimination of aripiprazole is mainly mediated through two enzymes, CYP2D6 and CYP3A4. Approximately 8% of Caucasians, 3–8% of Black/African Americans and up to 2% of Asians cannot metabolize CYP2D6 substrates and are classified as “poor metabolizers” (1).

The FDA-approved drug label for aripiprazole states that in CYP2D6 poor metabolizers, half of the usual dose should be administered. In CYP2D6 poor metabolizers who are taking concomitant strong CYP3A4 inhibitors (e.g., itraconazole, clarithromycin), a quarter of the usual dose should be used (Table 1) (2).

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My daughter had Genesight testing. I wish we had done it sooner. It was very helpful.

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We had the gene test done in January. Got back the results but were not able to do anything with them because my son decided to go off meds altogether. We were hoping to use these results to try and narrow down the med list. Not happy to hear that this might not be a good direction to go…

@kajlang It’s not a bad direction to go and the Dr can get some quality information. It just doesn’t give you all the answers. It told us the meds he could tolerate and it also showed us that he does have the MTHFR Gene mutation. We now follow the vitamin regimen for that deficiency. I looked at it as just an aid to this very foggy road.

Hmm, @Mojoclay , I haven’t done any reading on gene mutations at all. I think some time ago a gene oddity came up for my daughter. Oh, yes, I found it, “This individual is homozygous for the MTHFR A1298C variant (two copies). The MTHFR C677T variant was not identified.This MTHFR result is not associated with an increased risk of hyperhomocystenemia” I just did not understand what that meant back then, and still don’t.The doctor didn’t even mention any type of handling at the time. It was just noted on the test. So we didn’t do anything about it.

@GSSP has been away for a while, I hope things are okay for him and his crew. But in his absence I feel the need to comment on and speculate about the MTHFR genes. I mean these must be really bad genes huh? Real MTHFRs.

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… Chkl… nice pick-up MB! :+1:t3:
And I noticed that too. Wishing the best for him and his crew too.

Oh gosh, how did I miss that?? hehehe

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Received results today for my son. Interestingly, the medications he responds well to and the ones he has not received adequate benefit from align well with the use column descriptors. We are excited to review this with his new MD, a neuropsychiatrist, who has suggested far more adjunct therapies than his prior docs. Although only a few genes of the many that are possibly implicated in schizophrenia are tested, I think the test is worth a cheek swab to determine what meds have risks for possible future treatments.

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@Map, I’m curious which adjunct therapies your doctor is suggesting for your son. I’m a firm believer that AP therapy alone is incomplete threatment.

CBTp, daily exercise, neurology workup due at an abnormal finding on MRI which was deemed insignificant by prior psychiatrist and involvement in local peer support program. AP, can you define please?

Short for Anti Psychotic. Tons of acronyms here…

I spoke to my psychiatrist for my 19 year old son. She believes strongly about Genetic testing so I will get the kit. I will try anything to see if it works for him.