What can dna analysis of hair tell me besides ancestry?

June 28, 2024 10:07 AM

I would like to have dna from the hair in my deceased parent’s hairbrush analyzed, for whatever information it could provide, but particularly for what I suspect was mental illness. To what extent s this possible, and where might I have this done? There are many dna labs that test for paternity or criminal identification, but not for a profile this broad.
posted by mmiddle to Science & Nature (7 answers total)

Unfortunately, DNA analysis isn't going to tell you much, if anything, about your parent's predisposition toward mental illness. See this article from the National Institute of Mental Health (excerpt copied below):

Can genetic testing help predict my risk of developing a mental disorder?

Currently, genetic tests cannot accurately predict your risk of developing a mental disorder. Although research is underway, researchers are still learning about the ways genes can contribute to mental disorders—or protect against them. Of those genes that are linked to mental disorders, most raise the risk by tiny amounts.

While recent studies have begun to identify the genetic markers associated with certain mental disorders and eventually may lead to better screening and more individualized treatment, it is still too early to use genetic tests to diagnose or treat mental disorders.

posted by alex1965 at 10:34 AM on June 28 [2 favorites]

The DNA in hair is not easy to test. You need a root/bulb.
posted by soelo at 10:55 AM on June 28

The American National Institute of Health has a complete rundown on this topic.
posted by Tell Me No Lies at 10:59 AM on June 28 [1 favorite]

The hair strands might be ok to use to check for environmental stressors that can correlate with mental illness, such as environmental heavy metals, but testing protocols/accuracy/prioritization of specific studies will vary. If such exposures seem possible, I'd recommend working with a professional to assess your relative's likely risk and the best lab for such a study.

If you were considering storing hair strands with the bulb end/follicle attached in a clearly labeled sealed container kept in a cool dry place, be aware that DNA in the hair follicle does degrade and often is of poor quality and quantity for current testing - which is not saying that the extraction and testing protocols won't improve over time.

But all in all, it would be best to work with a professional first to assess risk based on family history, how your parent presented, and what studies your parent may have already done. Schizophrenia is different from depression is different from Alzheimer's, and familial Alzheimer's is different than sporadic occurance, and environmental factors can complicate all of it. If you've already done such a consult, then touching back with the professional every few years for updates would be the next recommendation.
posted by beaning at 1:29 PM on June 28 [1 favorite]

Response by poster: Thanks, each of you.
@beaning, how would I identify or locate such a professional?
posted by mmiddle at 4:14 PM on June 28

Check your MefiEmail link.
posted by beaning at 4:41 PM on June 28

Possibly get your own DNA done. You would get some insight into various risk factors that you may have inherited. But you probably need to consult w/ a geneticist to understand heritable diseases.
posted by mmf at 4:04 PM on June 29