Genetic Testing for Mold Sensitivity: The HLA-DR Gene

Genetic lab testing

Genes are a factor in mold sensitivity

Why do some people become chronically ill following an exposure to toxic mold, while others recover quickly OR have no symptoms at all?

Genes can be a factor in susceptibility to mold toxicity leading to serious health challenges. Those who carry a specific gene called the HLA-DR gene, can have difficulty recovering from mold and other toxin exposures. Allergies are also common with certain gene combinations related to mold and toxins.

It is estimated that 25% of Americans have the genetic predisposition to be affected by mold. However, is seems 100% of my family is susceptible, including my husband who is not genetically related to me. In a study of people affected by the mold being found in the Pensacola Judicial Building in Florida, it is estimated that 50% of the occupants who worked in the building experienced health challenges related to the mold there. Perhaps the 25% number is not accurate or high enough? In the United States, just 25% of the population is over 80 million people!

The 25% + of people who carry the HLA-DRBQ gene related to mold toxicity do not make the antibodies needed to deactivate and remove mold toxins. Their bodies cannot recognize the mold toxins as ‘bad guys’ to be eliminated. So the toxins get stored…

“Mold toxins are lipophilic, meaning their molecular structure consists of fatty acid molecules. For this reason, mold toxins migrate to and deposit in the brain because the brain is the ‘fattiest’ organ, consisting of 60% fat.”

Once mold toxins enter the brain, they start to destroy neurons and hormone production, and eventually lead to many other symptoms and chronic health issues including:

  • Autoimmune Diseases
  • Multiple Sclerosis
  • Rheumatoid Arthritis
  • Hashimoto’s Disease
  • Graves Disease
  • Scleroderma
  • Sjogren’s Syndrome
  • Parkinson’s Disease
  • Alzheimer’s Disease
  • Heart Disease
  • & more

A full list of possible mold exposure health symptoms is listed here.

A staggering 25 percent or more, of the population is genetically wired to have a tough time ridding itself of the deadly microbes associated with water-damaged buildings. For this group of individuals, the invading pathogens are not “tagged” and cleared by the body. Instead, they run freely. The body is then left to deal with the attackers in any way it can—which leads to inflammation, so often at the root of chronic conditions.

Blood testing

Blood testing is available to answer the question of genetic susceptibility to health effects related to mold toxins. The proper genetic test – HLA-DR – Genetic testing determines whether you are in the population of people genetically unable to properly detect and eliminate biotoxins from mold/lyme and other sources via the immune system.

HLA DR Testing Details

Test: HLA DR by PCR

Lab to Use: LabCorp

Spec: Lavender, room temp

Code #: 167120

DX Codes: 279.10, 377.34, 279.8

CPT Code: 81375

Additional blood tests can help determine if mold exposure is involved in health challenges. These tests include a series of immune inflammatory and other markers commonly out of range in CIRS/Biotoxin Illness as a result of mold/lyme.

C4A – Indicative of recent mold exposure. – TGF-Beta 1 – Indicative of longer term mold exposure. – MMP9 MSHVIPADH/OsmolalityAntiGliadin AntibodiesVEGF

More blood testing information

For an updated Lab Order Sheet – CLICK HERE

For an Physician Results Sheet CLICK HERE


C3a & C4a Testing Details

Lab To Use: Quest Labs

Lab testing procedures are critical for valid results. The current recommendation for C4a and C3a testing is to use Quest Labs for these tests, as the LabCorp testing is no longer valid for some reason. It is normal for results to take up to 4 weeks to return. Updated Lab Orders can be found above.


Cheryl Ciecko is an ALA, LEED AP, Licensed Architect who helps homeowners and building professionals create safe homes through online education to prevent mold, water damage, and poor indoor air quality. 


You can find her video masterclasses, online programs, and education subscription options at .


For detailed answers on your specific situation or building project, schedule your appointment for an individual consultation.




The information contained in this presentation is for educational purposes only and is not intended to diagnose, prescribe, treat, or cure any disease, ailment or injury to the body. It is not medical advice. FDA regulations prohibit the use of medical claims in conjunction with the sale of any product not approved by the FDA. Statements made herein have not been evaluated by the FDA. 

Any products, techniques, and/or personal usage tips referred to are not suggested as a replacement for proper treatment from a licensed health care professional. I am not a licensed health care professional and the decision to use or not to use any of this information is the sole responsibility of the listener and/or reader. Everyone is an individual with different body types, different blood types, different body chemistries, and it is important to remember that what works for one person may not work for another person.