Heavy metal is a broad term that describes a group of naturally occurring metallic elements of high molecular weight and density compared to water. At low concentrations, certain heavy metals, such as iron, zinc, copper, and manganese, are essential for human survival but can become toxic agents at higher concentrations. Other heavy metals, such as arsenic, cadmium, lead, thallium, and mercury, serve no biological role. However, they will inevitably enter the human body due to their presence in the environment. Similarly to essential metals, they induce toxicity once specific concentrations are reached.
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Fisher, Richard M. and Vikas Gupta. “Heavy Metals.” StatPearls, StatPearls Publishing, 27 February 2024.

ASARCO operated a smelter in Point Defiance Tacoma that pumped heavy metals like arsenic and lead up into our air. From 1888 to 1985 the toxic plume deposited toxins in the Puget Sound area soil and water.

​The Department of Ecology is still testing yards and and replacing yards in qualified areas. However, in order for your property to qualify for soil work it needs arsenic levels over 100 ppm or lead levels over 500ppm.

Pretty Gritty Tours has put together an amazing video telling the ASARCO story with so many great old photographs. ​

The Washington Department of Ecology is working to clean up yards in the Puget Sound.

It isn't just lead pipes that contaminate drinking water. If you have copper pipes or corroded galvanized pipes in your home, there can be lead in your drinking water. Even if your water district tests the water coming to your home, you could still have lead being added before the water comes out your faucet. Schools and daycares in Washington have a schedule for testing the water coming out of every single faucet. To prevent drinking and cooking with contaminated water, filter your water and/or get it tested. Click here for testing resources.

EPA FREQUENTLY ASKED QUESTIONS ABOUT DRINKING WATER PILOT STUDY
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The most common way that lead enters drinking water is through the corrosion of lead or galvanized iron plumbing.

EPA Frequently Asked Questions about Drinking Water Pilot Study
USS Lead Superfund Site www.epa.gov/uss-lead-superfund-site East Chicago, Indiana January 2017 
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LEAD TEST RESULTS FROM DRINKING WATER IN WA SCHOOLS

Schools must have their drinking water tested for lead at least once between July 1, 2014, and June 30, 2026. Retesting is required at least once every five years beginning July 1, 2026.
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Water--EPH-DW--4200, Drinking. “Lead Test Results from Drinking Water in Schools | Washington State Department of Health.” Doh.wa.gov, doh.wa.gov/community-and-environment/drinking-water/contaminants/lead/lead-schools/testing/test-results.

Silver amalgam fillings don't just contain silver. They are also made of zinc, tin, aluminum, and 50% mercury. Replacing these fillings with other non-metal materials can improve your health. It is important to only have amalgam fillings removed by a dentist that can do it safely and thus releasing the least amount of heavy metals into your body in the process.

HEALTH COMPLAINTS BEFORE AND AT ONE AND FIVE YEARS AFTER REMOVAL OF DENTAL AMALGAM RESTORATIONS-DATA FROM A PROSPECTIVE COHORT STUDY IN NORWAY

​In this study reduction of the intensity of symptoms after removal of amalgam restorations was observed, which suggests a possible dose–response relationship. 
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Sinha, Nivedita et al. “Health complaints before and at one and five years after removal of dental amalgam restorations - data from a prospective cohort study in Norway.” Acta odontologica Scandinavica vol. 83 219-229. 3 May. 2024, doi:10.2340/aos.v83.40260

A SAFE PROTOCOL FOR AMALGAM REMOVAL

Doctors and individuals request the removal of their amalgam (silver mercury) restorations due to the high mercury content. A safe protocol to replace the silver mercury filling will ensure that there is minimal if any absorption of materials while being removed. Strong alternative white composite and lab-processed materials are available today to create a healthy and functioning mouth. Preparation of the patient prior to the procedure and after treatment is vital to establish the excretion of the mercury from the body.

The following is a list of outcomes that I repeatedly hear from my patients over the years. Although I have not scientifically collected them, after amalgam removal and detoxification, they have also been reported in the literature. Comments include that

1. patients no longer have a metallic taste in their mouth;
2. patients feel as if they have more energy;
3. patients are able to concentrate better and make decisions easier (the “brain fog” is gone);
4. their body responds better to other treatments, as if a barrier has been lifted.

To achieve effective results one must include an integrative approach with a physician and health care team with attention to detoxification and diet over several months, with laboratory tests to monitor progress.
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Colson, Dana G. “A safe protocol for amalgam removal.” Journal of environmental and public health vol. 2012 (2012): 517391. doi:10.1155/2012/517391

Thimerosal contains a type of mercury called ethyl mercury. Thimerosal is a preservative used in some vaccines as a preservative. Since 2003 in the US you won't find it it childhood vaccines, but it is still used in multi-dose flu vaccines and one type of Td vaccine. It is still commonly used in less developed countries where it is impractical to transport a separate vial for each dose. 

​Many vaccines contain aluminum. Aluminum is an adjuvant. An adjuvant boosts your immune response thus making a vaccine more effective. 

When metals are injected a much higher percentage of them make it into your bloodstream than when they are ingested.

While many people are able naturally remove these metals injected into their bodies, some people are not so good at it. Body weight and genetics are factors. Inefficient detoxification leads to longer exposure times and increases the amount of metals able to cross the blood-brain barrier or get stored elsewhere in your body.

The website: JustTheInserts.com has done a great job of compiling all the vaccine product inserts. Look through the Table of Contents on a specific vaccine's insert and find "Description". The ingredients for that specific vaccine will be listed there. 

MERCURY IN VACCINES

Thiomersal, also called thimerosal, is an ethyl mercury derivative used as a preservative to prevent bacterial contamination of multidose vaccine vials after they have been opened.

Hessel, Luc. “Le mercure et les vaccins” [Mercury in vaccines]. Bulletin de l'Academie nationale de medecine vol. 187,8 (2003): 1501-10.

CHILDHOOD VACCINES AFTER 2003
UNDERSTANDING THIMEROSAL, MERCURY, AND VACCINE SAFETY

2003: All childhood vaccines with thimerosal as a preservative have passed their expiration date and are no longer available in the U.S. The amount of mercury in vaccines recommended for children is close to zero.
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Understanding Thimerosal, Mercury, and Vaccine Safety
Food and Drug Administration (FDA) 2011

MULTIDOSE VACCINES
VACCINE BASICS: U.S. CENTERS FOR DISEASE CONTROL AND PREVENTION

Most vaccines do not have any mercury in them. However, multi-dose flu vaccines and one type of tetanus-diphtheria (Td) vaccine contain a small amount of thimerosal. Flu and Td vaccines are also available in thimerosal-free versions.

CDC. “Vaccine Basics.” Vaccines & Immunizations, 2024, www.cdc.gov/vaccines/basics/.

VACCINES IN LESS DEVELOPED COUNTRIES
ABATING MERCURY EXPOSURE IN YOUNG CHILDREN SHOULD INCLUDE THIMEROSAL-FREE VACCINES

Newborns and infants in less developed countries have a concentrated schedule of Thimerosal-containing vaccines (TCVs); pregnant mothers are also immunized with TCVs.
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Dórea, José G. “Abating Mercury Exposure in Young Children Should Include Thimerosal-Free Vaccines.” Neurochemical research vol. 42,10 (2017): 2673-2685. doi:10.1007/s11064-017-2277-x

NEURODEVELOPMENT OF AMAZONIAN CHILDREN EXPOSED TO ETHYLMERCURY (FROM THIMEROSAL IN VACCINES) AND METHYLMERCURY (FROM FISH)

This study is distinguished from others by assessing co-occurring exposures of organic-Hg forms (chronic high fish-MeHg consumption, and acute EtHg-Al in TCVs from vaccines taken during pregnancy and in infancy). We found neurodevelopment delays to increase with time (from six to 24 months) and that co-occurring Hg exposures to significantly influence only Mental Developmental Index tests in Amazonian children.

Marques, Rejane C et al. “Neurodevelopment of Amazonian children exposed to ethylmercury (from Thimerosal in vaccines) and methylmercury (from fish).” Environmental research vol. 149 (2016): 259-265. doi:10.1016/j.envres.2015.12.022

EXAMINING THE EVIDENCE THAT ETHYLMERCURY CROSSES THE BLOOD-BRAIN BARRIER

22 studies from 1971 to 2019 show that exposure to ethylmercury-containing compounds (intravenously, intraperitoneally, topically, subcutaneously, intramuscularly, or intranasally administered) results in accumulation of mercury in the brain. 

Kern, Janet K et al. “Examining the evidence that ethylmercury crosses the blood-brain barrier.” Environmental toxicology and pharmacology vol. 74 (2020): 103312. doi:10.1016/j.etap.2019.103312

ENTRY AND DEPOSIT OF ALUMINUM IN THE BRAIN

Aluminum, as a known neurotoxicant, contributes to cognitive dysfunction and may contribute to Alzheimer's disease. The important reason is that aluminum can enter and be deposited in the brain. There have been three routes by which aluminum could enter the brain from systemic circulation or the site of absorption. Aluminum fluxes into brain across the blood-brain barrier (BBB), the choroid plexuses and the nasal cavity. Some factors, such as the increasing of the blood-brain barrier permeability, citric acid and parathyroid hormone (PTH), and vitamin D, can promote aluminum to enter the brain. But the redistribution of aluminum out of the brain is slow, so aluminum can be deposited in the brain for a long time.

Wang, Linping. “Entry and Deposit of Aluminum in the Brain.” Advances in experimental medicine and biology vol. 1091 (2018): 39-51. doi:10.1007/978-981-13-1370-7_3

AUTOIMMUNE/INFLAMMATORY SYNDROME INDUCED BY ADJUVANTS (ASIA) IN 2023

In 2011, a syndrome entitled ASIA (Autoimmune/inflammatory Syndrome Induced by Adjuvants; Shoenfeld's syndrome) was first described. ASIA aimed to organize under a single umbrella, the existing evidence regarding certain environmental factors which possess immune stimulatory properties, in order to shed light on a common pathway of autoimmune pathogenesis. Such environmental immune stimulators, or adjuvants, include among others: aluminum salts as in vaccines, various medical implants, as well as various infectious agents.

Typical clinical symptoms of ASIA are: chronic fatigue, arthralgias, myalgias, pyrexia, sicca symptoms, cognitive impairment, and or (atypical) neurological symptoms. Typically, patients present with severe fatigue, nonrestorative sleep, and a majority reporting post-exertional malaise as is observed in ME/CFS. 

Cohen Tervaert, Jan Willem et al. “Autoimmune/inflammatory syndrome induced by adjuvants (ASIA) in 2023.” Autoimmunity reviews vol. 22,5 (2023): 103287. doi:10.1016/j.autrev.2023.103287

Toxins can be found in our food in many and unpredictable ways. Mercury in fish. Arsenic in rice. Even mixed juices contain toxins. Fish that are higher on the food chain, that grow slower, and live longer accumulate more toxins. Safer fish choices include clams, cod, salmon, and tilapia. Bonus points for sardines because they are high in selenium.

HEAVY METALS IN FOODS AND BEVERAGES

Heavy metal toxicity is directly related to their accumulation in food. High amounts of these elements generate numerous health issues. Therefore, consumers must choose their food sources carefully. Metals like lead, cadmium, and arsenic are the main elements with high potential health risks. According to the analyzed studies, the highest value for cadmium was registered in lettuce cultivated in Romania; excessive amounts of lead were found in apple samples from Ukraine and Kosovo, but also in lettuce or red potatoes from Romania; and arsenic presented alarming values in lettuce from Florida. 
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Scutarașu, Elena Cristina, and Lucia Carmen Trincă. “Heavy Metals in Foods and Beverages: Global Situation, Health Risks and Reduction Methods.” Foods (Basel, Switzerland) vol. 12,18 3340. 6 Sep. 2023, doi:10.3390/foods12183340

TOXIC AND ESSENTIAL ELEMENTS IN RICE AND OTHER GRAINS

White rice from Thailand, India, and Italy showed higher median concentrations of toxic metal such as As, Pb, and Cd compared to white rice from the US. Lead and Cd concentrations did not exceed the codex standards; however, Arsenic (As) concentrations in brown rice and one white rice from US exceeded the codex standards.
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TatahMentan, Mom et al. “Toxic and Essential Elements in Rice and Other Grains from the United States and Other Countries.” International journal of environmental research and public health vol. 17,21 8128. 3 Nov. 2020, doi:10.3390/ijerph17218128

CONTAMINENTS IN FISH AND CLAMS IN SINCLAIR AND DYES INLET 1992

Concentrations of several metals in fish from Sinclair and Dyes Inlets exceeded those found in comparable studies in the same area and were equivalent or higher than fish from other urban bays. Most importantly, mercury in fish in the present study (0.4 mg/kg) approached the FDA action limit of 1 mg/kg. The California limit is 0.5 mg/kg.
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Contaminants in Fish and Clams in Sinclair and Dyes Inlet
Washington State Department of Ecology 1992
https://apps.ecology.wa.gov/publications/documents/92e09.pdf

SEPARATING THE EMPIRICAL WHEAT FROM THE PSEUDOSCIENTIFIC CHAFF: A CRITICAL REVIEW OF THE LITERATURE SURROUNDING GLYPHOSATE, DYSBIOSIS AND WHEAT-SENSITIVITY
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While the current review focused on the agricultural practice of desiccating wheat, it should be noted that many crops, including legumes, corn, and soy, have been shown to contain high glyphosate residues due to desiccation and the advancement of glyphosate-resistant crops. Eliminating wheat from one’s diet does not guarantee the elimination of glyphosate exposure. However, wheat products have been shown in independent testing to contain higher residues post-processing and make up a significant portion of the average North American’s dietary glyphosate exposure.

Barnett, Jacqueline A, and Deanna L Gibson. “Separating the Empirical Wheat From the Pseudoscientific Chaff: A Critical Review of the Literature Surrounding Glyphosate, Dysbiosis and Wheat-Sensitivity.” Frontiers in microbiology vol. 11 556729. 25 Sep. 2020, doi:10.3389/fmicb.2020.556729

Fires release particulates and heavy metals into the air. Trees absorb heavy metals, but when homes and other man made structures burn, that's when the pollution is the worst.

METAL TOXIN THREAT IN WILDLAND FIRES DETERMINED BY GEOLOGY AND FIRE SEVERITY

Accentuated by climate change, catastrophic wildfires are a growing, distributed global public health risk from inhalation of smoke and dust. Underrecognized, however, are the health threats arising from fire-altered toxic metals natural to soils and plants. Here, we demonstrate that high temperatures during California wildfires catalyzed widespread transformation of chromium to its carcinogenic form in soil and ash, as hexavalent chromium, particularly in areas with metal-rich geologies (e.g., serpentinite). In wildfire ash, we observed dangerous levels (327-13,100 µg kg−1) of reactive hexavalent chromium in wind-dispersible particulates.

Lopez, A.M., Pacheco, J.L. & Fendorf, S. Metal toxin threat in wildland fires determined by geology and fire severity. Nat Commun 14, 8007 (2023). https://doi.org/10.1038/s41467-023-43101-9

BEYOND PARTICULATE MATTER MASS: HEIGHTENED LEVELS OF LEAD AND OTHER POLLUTANTS ASSOCIATED WITH DESTRUCTIVE FIRE EVENTS IN CALIFORNIA

This study finds elevated concentrations of metals mobilized by wildfires destroying infrastructure in California over the last decade, raising potential health concerns for downwind communities.

Boaggio, Katie et al. “Beyond Particulate Matter Mass: Heightened Levels of Lead and Other Pollutants Associated with Destructive Fire Events in California.” Environmental science & technology vol. 56,20 (2022): 14272-14283. doi:10.1021/acs.est.2c02099

ARE SOME METALS IN TATTOO INKS HARMFUL TO HEALTH?
In this study, amounts of some metals were measured in samples taken from the market, and some of the amounts were found to be above the concentrations specified in the guidelines and in amounts that could pose a risk to public health. Reliable results were obtained by validating the method and choosing the best acid combination for the preparation of the samples.
Many people may not be aware that they can get harmful effects by the chemicals of tattoo inks. We believe that it will be beneficial to make the results open to public and to inform tattoo artists and people who have tattooed, albeit limited, when deciding to purchase tattoo ink.
Karadagli, Sumru Sozer et al. “Are Some Metals in Tattoo Inks Harmful to Health? An Analytical Approach.” Chemical research in toxicology vol. 36,1 (2023): 104-111. doi:10.1021/acs.chemrestox.2c00323

Our air quality is negatively impacted ground-level ozone, particle pollution, carbon monoxide, sulfur dioxide, and nitrogen dioxide.

SHORT SUMMARY OF THE 2023 TACOMA AND SEATTLE AIR TOXICS STUDY

The study confirmed that diesel exhaust (from trucks, ships, trains, etc.) contributes most of the health risk from air toxics. Hexavalent chromium (in industrial areas) and wood smoke were the next highest, each contributing about 5% of the total risk.
We also found Black, Indigenous, and other people of color and lower income households in our region have higher potential cancer risks from air toxics due to living near major roadways.
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Puget Sound Clean Air Agency: Short Summary of the 2023 Tacoma and Seattle Air Toxics Study
https://pscleanair.gov/DocumentCenter/View/5442/2023-Air-Toxics-Community-Report

Heavy metals block the absorption of Vitamin D. Additionally, Vitamin D may "help" heavy metals be absorbed and retained in your body. 

Tobacco products are found to contain lead, cadmium, nickel, chromium, arsenic, and mercury. Different products and different brands have varying concentrations of each.

REVIEW OF CIGARS AND CIGAR-TYPE PRODUCTS AS POTENTIAL SOURCES OF CONSUMER EXPOSURE TO HEAVY METALS

Among the heavy metals, the following contents of elements in tobacco were recorded in cigars: Fe (420–2200 µg/g), Mn (100–370 µg/g), Zn (14–180 µg/g), Cu (15–140 µg/g), Pb (not detected–32 µg/g), Cd (nd–19 µg/g), Ni (nd–13 µg/g), Cr (nd–10 µg/g), Co (0.65–1.0 µg/g), As (nd–0.66 µg/g), Hg (18–25 ng/g). Importantly, the values often differ between cigars of different origins and types, indicating the need for more extensive research.

Hać, Paweł Jacek et al. “Review of cigars and cigar-type products as potential sources of consumer exposure to heavy metals.” Journal of environmental science and health. Part C, Toxicology and carcinogenesis vol. 40,2 (2022): 172-196. doi:10.1080/26896583.2022.2052708

TOXIC METAL CONCENTRATIONS IN CIGARETTES OBTAINED FROM U.S. SMOKERS IN 2009: RESULTS FROM THE INTERNATIONAL TOBACCO CONTROL (ITC) UNITED STATES SURVEY COHORT
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Cigarettes obtained from a sample of smokers in the United States were found to contain metals that could potentially be harmful to human health. The average metal concentrations observed per gram of unburned tobacco were comparable to amounts found in cigarettes on the US, Canadian, and Brazilian markets, but less than those found in cigarettes purchased in China.

Caruso, Rosalie V et al. “Toxic metal concentrations in cigarettes obtained from U.S. smokers in 2009: results from the International Tobacco Control (ITC) United States survey cohort.” International journal of environmental research and public health vol. 11,1 202-17. 20 Dec. 2013, doi:10.3390/ijerph110100202

UNTESTED, UNSAFE? CANNABIS USERS SHOW HIGHER LEAD AND CADMIUM LEVELS

Cannabis belongs to a class of plants known as hyperaccumulators because their tissues can accumulate metals from soil, water, fertilizers, and other sources at levels hundreds or thousands of times greater than is normal for most plants.

Researchers with Columbia University reviewed data from the National Health and Nutrition Examination Survey (NHANES) between 2005 and 2018 representing 7,254 participants who completed a drug use questionnaire and provided single samples of blood and urine. In their analysis, the researchers adjusted for factors that may affect exposure to metals and their excretion. These included race/ethnicity, age, sex, education, tobacco use, and seafood consumption.
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They found that survey participants who reported using marijuana but no tobacco in the previous 30 days had higher levels of cadmium and lead in their blood and urine than did those who had used neither marijuana nor tobacco. Users had cadmium levels on average 22% higher in blood and 18% higher in urine than nonusers. Lead levels were higher by 27% in blood and 21% in urine. None of the 15 other elements evaluated—including arsenic, cobalt, manganese, mercury, and uranium—showed a clear association with cannabis use.

Seltenrich, Nate. “Untested, Unsafe? Cannabis Users Show Higher Lead and Cadmium Levels.” Environmental health perspectives vol. 131,9 (2023): 94001. doi:10.1289/EHP13519

METAL/METALLOID LEVELS IN ELECTRONIC CIGARETTE LIQUIDS, AEROSOLS, AND HUMAN BIOSAMPLES: A SYSTEMATIC REVIEW

Numerous metals/metalloids—Al, Sb, As, Cd, Co, Cr, Cu, Fe, Pb, Mn, Ni, Se, Sn, and Zn—were present in e-cigarette samples in the studies reviewed. For most metals/metalloids, levels were heterogeneous according to sample (e-liquid, aerosol), source of the sample (bottle, cartridge, open wick tank), and device type (cig-a-likes and tank). Studies of biosamples support the hypothesis that e-cigarettes are a source of metals/metalloids because most metal/metalloid biosample levels, with the exception of Cd, were similar or even higher in e-cigarette users in comparison with conventional cigarette users, and higher in comparison with cigar users. The direct comparison of metal/metalloid aerosol levels to human biosample levels also provides direct support for the hypothesis that aerosol metals/metalloids are inhaled and absorbed by the e-cigarette user.
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In comparison with conventional cigarettes, e-cigarette aerosols may result in less exposure to Cd but not to other toxic metals/metalloids found in tobacco. 

Zhao, Di et al. “Metal/Metalloid Levels in Electronic Cigarette Liquids, Aerosols, and Human Biosamples: A Systematic Review.” Environmental health perspectives vol. 128,3 (2020): 36001. doi:10.1289/EHP5686

Largely airplanes have shifted away from using leaded fuel. However, there are still 220,000 smaller older aircraft still using leaded fuel. Communities near airports that serve these piston-engine aircraft are still suffering from increased lead exposure. The FAA is partnering with the aviation community to eliminate leaded fuels by 2030.

EPA DETERMINES THAT LEAD EMISSIONS FROM AIRCRAFT ENGINES CAUSE OR CONTRIBUTE TO AIR POLLUTION

Aircraft that operate on leaded aviation gasoline are typically small piston-engine aircraft that carry 2-10 passengers. These aircraft are approximately 45 to 47 years old, on average, depending on the type of aircraft. Jet aircraft used for commercial transport, on the other hand, do not operate on leaded fuel. Levels of airborne lead in the United States have declined 99% since 1980, but emissions from aircraft that operate on leaded fuel may still pose risks to nearby communities, including those with environmental justice concerns. 

EPA Determines that Lead Emissions from Aircraft Engines Cause or Contribute to Air Pollution
United States Environmental Protection Agency 2023
https://www.epa.gov/newsreleases/epa-determines-lead-emissions-aircraft-engines-cause-or-contribute-air-pollution

BUILDING AN UNLEADED FUTURE BY 2030

The FAA and partners in the aviation community launched the EAGLE initiative as the result of a Congressionally mandated report from the National Academies. The EAGLE team’s goal is to eliminate leaded aviation fuels in piston-engine aircraft safely by the end of 2030.
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“EAGLE Initiative | Federal Aviation Administration.” Faa.gov, 2022, www.faa.gov/unleaded.
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The field of genetics is relatively young. We are still searching for all the genetic connections impacting our ability to remove toxins from our bodies. Some connections have already been found. Bearing in mind that genes are not always expressed (turned on) we are seeing genetic predispositions to heavy metal toxicity.

THE IMPACT OF GENETIC VARIATION ON METABOLISM OF HEAVY METALS: GENETIC PREDISPOSITION?

The study of genetic variations and their interactions with environmental factors can provide an extra chance to elucidate individuals’ susceptibility to heavy metals. Nowadays, it is well-known that the genetic based factors and in general genetic background are just one part of a bigger complex in defining heavy metal sensitive individuals. In here, other internal and external elements are playing a substantial role. Such inter-individual genetic differences, along with other environmental factors can make a unique phenotype and consequently a distinctive response of individuals to encountered toxins. Therefore, identification of variations in head related genes, as well as their interactions with other environmental factors will provide important data not only about the individual differences and identification of susceptible groups, but also for developing novel preventively or/and therapeutic approaches.

In this review, we briefly discussed various experiments investigating genetic variations in different genes, which are directly (MT, GST, etc.) or indirectly (PON1, MTHFR, etc.) related to heavy metals and their body metabolisms. 

Joneidi, Zeinab et al. “The impact of genetic variation on metabolism of heavy metals: Genetic predisposition?.” Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie vol. 113 (2019): 108642. doi:10.1016/j.biopha.2019.108642

ASSOCIATION BETWEEN MTHFR C977T/A1298C AND SUSCEPTIBILITY TO AUTISM SPECTRUM DISORDERS: A META-ANALYSIS

The findings of the meta-analysis indicated that MTHFR C677T polymorphism is remarkably associated with ASD in the five genetic models, viz., allelic, dominant, recessive, heterozygote, and homozygote. However, the MTHFR A 1298C polymorphism was not found to be significantly related to ASD in the five genetic models. Subgroup analyses revealed significant associations of ASD with the MTHFR (C677T and A1298C) polymorphism.

Li, Yan et al. “Association between MTHFR C677T/A1298C and susceptibility to autism spectrum disorders: a meta-analysis.” BMC pediatrics vol. 20,1 449. 24 Sep. 2020, doi:10.1186/s12887-020-02330-3

GENETIC DISORDERS ASSOCIATED WITH METAL METABOLISM

Metabolic disorders related to metals are regarded as quintessential single-gene disorders. However, in recent years, advances in next-generation sequencing and other advanced technologies have revealed that the classical "one gene–one enzyme" paradigm is not always the culprit. It has been reported that defects in multiple genes may lead to the same phenotypic presentation. Furthermore, mutations in different domains of the same protein might produce a difference in the phenotypes. Thus, it very difficult to pin-point a specific mutation and proceed with therapeutic strategies as different mutations respond differently during therapy. This process is not homogeneous across diseases and specific mutations.
In addition, next-generation sequencing has also shown that affected individuals with hybrid phenotypes might have mutations in more than two different genes that are responsible for causing more than two phenotypes in the same individual, which leads to a complex phenotype. Such complex genetic disorders are very difficult to diagnose and become increasingly difficult to manage with a therapeutic plan. Newly discovered disease-causing genes and disorders associated with metal metabolism have provided us with insight into the basics of the micronutrients that are required for the proper maintenance of the human body. Advances in the fields of molecular diagnostics and precision medicine have allowed us to understand more about the metabolism, regulation, and functions of these micronutrients, which will ultimately lead to new therapeutic strategies. However, we still have a lot to learn.

Umair, Muhammad, and Majid Alfadhel. “Genetic Disorders Associated with Metal Metabolism.” Cells vol. 8,12 1598. 9 Dec. 2019, doi:10.3390/cells8121598

MTHFR DEFICIENCY IN BIOLOGICAL SIBLINGS DIAGNOSED WITH AUTISM AND ATTENTION-DEFICIT HYPERACTIVITY DISORDER (ADHD): A REPORT OF TWO CASES

Much research has been dedicated to learning about one of the most important enzymes involved in folate metabolism and pathways involving catecholamine neurotransmitters. The MTHFR C677T mutation is the most common MTHFR mutation. In fact, the MTHFR 677CT mutation is found to be among the genes associated with the increased risk for autism in individuals and is further found in mothers of kids with autism. This, by no means, is a direct correlation of MTHFR C677T to the diagnosis of ASD since ASD and its variability is due to multiple cofactors between genes and multiple environmental factors.
Decreased MTHFR activity, which results in decreased folate metabolism, can be seen in multiple psychiatric illnesses such as schizophrenia, bipolar disorder, depression, ASD, and ADHD. As discussed, research indicates the positive effects of l-methylfolate as adjunctive therapy for certain mental health illnesses. Nevertheless, more research using behavioral scales studying the acute and chronic changes in mood and behaviors with and without the supplement in patients with behavioral health needs would be beneficial and be able to add to the medical knowledge within behavioral health. Studies have yet to show concrete evidence that folate supplements can be helpful in treating mental health illness, but they have demonstrated the importance of being able to detect the MTHFR deficiency in patients with and without mental health illnesses in order to develop a strategic treatment plan to help treat the individual with specific supplements such as folate, L-methylfolate, folic acid, and/or cobalamin.
Khan, Samira, and Abeera Naeem. “MTHFR Deficiency in Biological Siblings Diagnosed With Autism and Attention-Deficit Hyperactivity Disorder (ADHD): A Report of Two Cases.” Cureus vol. 15,3 e36294. 17 Mar. 2023, doi:10.7759/cureus.36294

ROLE OF MTHFR 677C>T AND 1298A>C GENE POLYMORPHISMS ON RENAL TOXICITY CAUSED BY LEAD EXPOSURE IN WASTEWATER TREATMENT PLANT WORKERS
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The WWTP workers carrying MTHFR 677TT as well as MTHFR 1298CC are more vulnerable to elevation of the Pb excretion in their urine, and elevation in the homocysteine levels than the workers carrying MTHFR 677CC/CT or MTHFR 1298AA/AC, respectively. These elevations in Pb and homocysteine, as well as MDA, could lead to elevation in the urea and creatinine among them. Therefore, the polymorphisms of these two genes could be used as predictor gene susceptibility to kidney impairments among those sludge exposed workers.

Saad-Hussein, Amal et al. “Role of MTHFR 677C>T and 1298A>C gene polymorphisms on renal toxicity caused by lead exposure in wastewater treatment plant workers.” Environmental science and pollution research international vol. 30,35 (2023): 84758-84764. doi:10.1007/s11356-023-28309-y