According to the IRS pg 16 https://www.irs.gov/pub/irs-pdf/p502.pdf, you can't include the cost of nutritional supplements, vitamins, herbal supplements, “natural medicines,” etc., unless they are recommended by a medical practitioner as treatment for a specific medical condition diagnosed by a physician. These items are taken to maintain your ordinary good health and aren't for medical care.
Under the IRS Private Letter Ruling 201933005 https://www.irs.gov/pub/irs-wd/201933005.pdf genetic testing may be considered an eligible medical expense.
The burden is on the consumer to provide the necessary documentation to the IRS regarding qualified eligible expenses when using tax-deferred HSA/FSA funds. We strongly recommend that you seek advice from your tax advisor before purchasing Seeking Health products using HSA/FSA funds.