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HLA genetics and mold

The HLA-DR Gene and Mold Sensitivity

Why is it that mold affects each person differently? How come some people present no symptoms at all or they tend to recover from symptoms as soon as the source of the mold is eradicated, while others develop chronic health problems from a single encounter with mold? The answer lies in a person’s genetic predisposition toward mold illness, which stems from the HLA-DR gene.

Note to readers: The particulars behind HLA-DR’s problematic effect on the immune system require delving into expansive details of the Major Histocompatibility Complex (MHC) in humans, as well as the definition and functions of various molecules and proteins—such as antigens, peptides, and T-cell receptors, to name a few—in relation to the pituitary and hypothalamic axis, and the immune system as a whole. For those of you who are biology buffs, I apologize for oversimplifying things. And, for those of you who dreaded every day of high school biology, well, you’re welcome.

Without further ado, let’s jump right in and butcher a very complex problem with a very modest explanation.

What is the HLA-DR Gene?

The Human Leukocyte Antigen is a protein—or marker—that is found on most cells in your body. Your immune system uses these markers to recognize which cells belong in your body and which cells do not. When an antigen is presented correctly to a T-cell receptor, for example, the appropriate immune response is given and foreign threats can be destroyed or removed from the body. This is an imperative function in the defense against biotoxins—toxic substances that have an organic origin, such as mycotoxins (fungi—yeast and mold), zootoxins (animals), and phytotoxins (plants).

When a person carries the HLA-DR gene, however, they are genetically susceptible to biotoxic illnesses because the HLA-DR causes a misprocessing of antigens, which inhibits the immune system from reacting correctly to infection and toxins.

HLA-DR and Mold Illness

Fungal triggers of the HLA-DR are often the most devastating to health. Over 36 different diseases can result from an HLA-DR carrier’s exposure to mold. This is because HLA-DR(BQ) inhibits the immune system from recognizing mycotoxins as a threat, thus impeding it from producing antibodies that are needed for deactivating and removing mold toxins. Because of this, mycotoxins and aflatoxins are stored throughout the body (namely in the “fatty” regions, such as the brain) while their negative effects go undiagnosed or incorrectly treated by the immune system for weeks, months, years, or even a lifetime.

Because the mycotoxins are misprocessed and stored, the immune system will overreact to toxic and non-toxic materials. It can lose its ability to correctly differentiate between “self” and “foreigner,” often misfiring and wreaking more havoc on the body than the mycotoxins would have done on their own. In short, HLA-DR and mold illness are synonymous with autoimmune disease and disorder.

When a group is exposed to mold, the HLA-DR carriers will be the first to experience an immune response and the last to recover—if they recover at all. Rarely does the HLA-DR victim suffer only the first line of defense markers for mold sickness, such as:

  • watering, irritated eyes
  • red eyes
  • hives
  • sneezing
  • runny nose
  • nausea
  • vomiting
  • burning sensations in airways
  • a tightening in the chest
  • cough
  • nuances of asthma
  • nosebleed
  • fever
  • numbness/tingling
  • a long, painful headache

Instead, they’re more likely to experience many of those symptoms long term and more intensely than non-carriers who were exposed to the same mold for the same duration of time. In addition, they’re now more susceptible to other chronic and seemingly-unrelated illnesses, disorders, and diseases (because HLA-DR permits the storing of mold toxins that eventually destroy neurons in the brain and disrupt hormone production):

Acne (cystic, as well)



Autoimmune diseases

Balkan nephropathy (a type of kidney disease)

Brain disorders

Bronchitis (repeat occurrences)

Celiac disease (severe gluten intolerance that puts the small intestine at risk)

Chronic sinus congestion

Colitis (inflammation of the colon lining)

Dry skin (dull, ashy-looking skin, cracked heels, chapped lips)

Epstein-Barr Virus (“Mono”)

Gastrointestinal issues

Graves Disease (i.e. hyperthyroidism)

Gum disease

Hashimoto’s Disease (autoimmune disease that damages the thyroid gland)

Heart Disease

Hepatocellular carcinoma (primary type of liver cancer)

Histamine intolerance

Insulin resistance

Irritable Bowel Syndrome (IBS)

Joint-connective tissue disorders

Kashin-Beck disease (death of bone and joint cartilage growth plates, resulting in disruption of normal growth in children and adolescents)

Lupus (inflammatory autoimmune disease that attacks the body’s healthy tissues and organs)

Lyme’s disease

Memory problems (short term)

Multiple Sclerosis

Parkinson’s Disease


Respiratory infections

Reye’s syndrome (swelling in the liver and brain—mostly occurs in children and teenagers)

Rheumatological disorders (r. arthritis)

Scalp issues (lesions, rashes, acne, abscesses, cysts)


Sjogren’s Syndrome

“Static shock” occurrences more frequent (caused by higher salt content due to dehydration)

Thirst (unquenchable)

Thyroid dysfunction

Weight gain (sudden)

Worsening vision

And so much more…

What Are the Chances That You Are a Carrier of the HLA-DR Gene?

So far, it’s been established that roughly 25% of the population is a carrier (and sufferer) of the HLA-DR gene. That’s over 80 million people in the United States alone! New research, however, is emerging that indicates that the initial assessment could be drastically inaccurate. Genetic studies on certain populations now suggest that the true number could be anywhere between 40% and 60% worldwide!

In one study conducted on four different populations, including an isolated Hutterite population, it was determined that, while those working regularly in agriculture showed mildly increased cases of mold sensitivity and asthmatic symptoms, the predisposition toward mold sensitivity and related allergens/illnesses, certainly appears to be genetic and estimated to affect around 60% of the population. It was originally assumed that isolated “inbred” groups (closely and distantly related) were more likely to pass on these susceptibility genes, but after expanding their research to include several “outbred” groups from large, multi-racial cities, they discovered that cases of genetic mold sensitivity only dropped by 10 to 20% (due to gene variance). In other words, this alarmingly high percentage of genetic mold sensitivities is not dependent on tight-knit communities of distant cousins, nor is it dependent on whether or not the lifestyle centers on agriculture. Even the most genetically-diverse populations teeter between 40% and 60% (as mentioned before).

Is There Anything Good About Having the HLA-DR Gene?

Several health professionals and genetics experts would argue that carriers of the HLA-DR mold-sensitivity gene act as canaries for the health and safety of the population at large.

Mold affects everyone, even those who aren’t genetically vulnerable to it. Some mold victims seem to be asymptomatic, but given enough exposure time to a toxic mold, they’ll eventually succumb to a mold-related illness or disorder. Mold is not always growing where it is visible to the naked eye, especially in older buildings. Centuries-old homes, apartments, and municipal buildings, for instance, often have deep rot and mold infestation within the inner structures. This is why, in a sense, it is good to have HLA-DR carriers because their immediate immune response to mold could act as a warning sign to others in a home or workspace that mold is present. (Of course, this is assuming the carrier and others are able to diagnose the symptoms correctly.)

What Can Be Done if You are a Carrier of HLA-DR?

While it does leave the immune system vulnerable to biotoxins, it doesn’t have to be a death sentence. The most important point to take home, regarding HLA-DR, is that it is genetic, which means that, if you are a carrier, the effects of the HLA-DR gene will permanently govern the way you live your life. While your spouse, friends, or coworkers may experience a restoration of full health once mold exposure is diminished, you will have to actively encourage your body to heal from mold illness with lifestyle choices, such as an anti-fungal diet or an anti-fungal supplement routine, in addition to detoxing exercise and adequate sleep.

In other words, HLA-DR carriers, unlike non-carriers, will have to actively pursue a course of treatment and live a specific lifestyle that promotes biotoxin shedding.

Testing for the HLA-DR Gene

WARNING: If you believe you are a carrier of the HLA-DR gene, please do NOT pursue testing through commercial DNA testing agencies, such as 23andMe, AncestryDNA, National Geographic Geno 2.0, or any other like service. These agencies are not required by law to follow HIPAA guidelines, which means they have the right to sell your genetic panel to insurance companies. This could result in a denial of insurance coverage or a rise in the cost of insurance should you prove to have pre-existing conditions or medical predispositions.

For the most part, testing for the HLA-DR gene is not necessary when determining treatment options for the various illnesses and disorders encouraged by it. However, it might be helpful to a potential carrier if they obtain proof of their genetic susceptibility to mold sickness for the purpose of cautiously planning their lifestyle and living conditions, as well as establishing medical or legal recourse in the case of inept diagnoses and property negligence.

Unless you are able to convince your doctor to see the HLA-DR genetic panel as a necessity in their diagnosis and treatment, be aware that insurance will not cover the blood tests or the reading of the test results. In general, prices range between $300 and $400 if you must order the testing yourself.

Blood testing for HLA-DR is available through the LabCorp and Life Extension laboratories.

Important Note: Those familiar with the Quest Diagnostics laboratory should not confuse their HLA blood test for the HLA-DR mold illness susceptibility panel. A standard HLA blood test will only yield results in terms of tissue donor matching. Quest Diagnostics does offer the C3A and C4A tests that determine whether a person has been exposed to mold recently or long term, but those tests will not shed light on underlying genetic susceptibilities and are only useful in certain scenarios.


Unbeknownst to many, the HLA-DR gene affects between 40% and 60% of the world’s population. It accounts for a greater susceptibility to yeast and mold illnesses, as well as autoimmune diseases.

Carriers of the HLA-DR gene are prone to develop chronic health issues involving systemic inflammation, whether the cause is mold, Lyme’s, gluten, or countless other catalysts. Not only does HLA-DR make a carrier vulnerable to chronic biotoxin disease, it also makes detoxification and healing extremely difficult. Thankfully, there is hope with a strict adherence to preventative and detoxifying protocols.

For more information regarding mold, mold prevention, and mold solutions, please check out the rest of

Article by Amanda Demsky from the MoldBlogger team.

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When I was pregnant with my third, we were renting an apartment and each day in the summer, when the sun hit our southern wall, which was the wall in the kitchen, a smell that made me feel sicker than my normal morning sickness with the pregnancy began to grow and get stronger as the suns rays heated up that side of our home. I told my husband that there must be mold in that wall (I have had previous experience with mold sickness and was having symptoms again). Finally, he did some investigating behind the dishwasher and found the mold, and a leak from a slice in the plumbing that was continuously pouring in the surrounding wall. Apparently, whomever had been hired to do the plumbing for the apartment had cut the pipe in the wrong spot and then cut in the right spot, but then installed the partially cut pipe that leaked from day one! Always double check your plumbing to make sure there are no leaks that will grow a garden of mold in your home.

Do You Feel Sicker at Home?

Are you constantly feeling sick, and is it worse when you are at home? Do you experience unexplained respiratory issues, headaches, etc? Sick building syndrome is a real issue that many occupants of homes and buildings suffer from. The NCBI characterizes the signs and symptoms of sick building symptoms as: “Headache, dizziness, nausea, eye, nose or throat irritation, dry cough, dry or itching skin, difficulty in concentration, fatigue, sensitivity to odors, hoarseness of voice, allergies, cold, flu-like symptoms, increased incidence of asthma attacks and personality changes.” There can be many factors related to sick building symptom other than mold, and the cause of it is unknown, however, if you constantly feel sicker at home and suspect a possible mold problem, you may want to test your home for that possibility. 

Test Your Home

If you an unsure whether or not your home is infested with mold, or if you are purchasing a home and want to make sure you are not buying a mold headache to deal with, it may be a great idea to test your home for mold. There are many different ways to test your home, whether by hiring a professional to inspect and test, or by performing your own mold test, such as an ERMI dust test. It is a good idea to research which option is the best and most thorough way to test for your budget and situation.

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