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Disclaimer: This article is for informational purposes only and is not intended for diagnostic use. LifeDNA does not provide diagnostic reports on any traits discussed. Genetics is just one piece of the puzzle; please consult a healthcare professional for comprehensive guidance on any health condition.
Pernicious anemia may sneak up on someone without them realizing that they actually have a serious condition. At first, they might just feel tired or experience brain fog, symptoms easy to brush off as everyday stress or busy life. But underneath, their body isn’t absorbing enough vitamin B12 because of an immune system issue. Genetics may also play a role, making some people more likely to develop this condition. Knowing about these hidden connections can help them get diagnosed and treated sooner.
Recent statistics shows that Pernicious anemia typically affects people between the ages of 60 and 80, especially those of Northern European descent. In the United States, it is estimated to affect about 151 in every 100,000 people. Although it is more common in this group, anyone may develop the condition.
Understanding this condition is important because the early symptoms are often subtle and easy to miss. If this is left untreated, it may lead to serious complications, including nerve damage and cognitive issues. Being aware of the symptoms and risk factors may help people seek timely medical advice and improve their quality of life.
Pernicious anemia is a type of megaloblastic anemia, a type of anemia where the body produces unusually large and immature red blood cells that don’t work properly. This happens because the body lacks important nutrients, usually vitamin B12 or folate (vitamin B9) that are needed to make healthy red blood cells. As a result, the blood can’t carry enough oxygen to the body’s tissues, causing symptoms like tiredness and weakness.
The root cause is typically an autoimmune response that attacks the stomach’s parietal cells or intrinsic factor, a protein necessary for vitamin B12 absorption. Without adequate vitamin B12, the body can’t produce healthy red blood cells, leading to symptoms like fatigue, weakness, numbness, and cognitive difficulties.
You may want to read: How Genetics May Affect Vitamin B12 Levels
Pernicious anemia symptoms often develop slowly and may be mistaken for other conditions, especially in the early stages. Because vitamin B12 is involved in red blood cell formation and neurological health, symptoms can affect many systems in the body.
Primary Causes:
The main cause of pernicious anemia is when the body’s immune system makes a mistake and attacks components in the stomach that help absorb vitamin B12. Normally, special cells in the stomach called parietal cells make a protein called intrinsic factor. This protein is needed to help the body take in vitamin B12 from food.
In people with pernicious anemia, the immune system creates antibodies that destroy these parietal cells. Sometimes, the antibodies attack the intrinsic factor protein itself, stopping it from working properly. Because of this, the body can’t absorb enough vitamin B12, which is important for making healthy red blood cells. Also, long-term swelling and damage in the stomach lining, called autoimmune gastritis, often happens along with pernicious anemia and makes the problem worse.
Other Contributing Factors:
Aside from problems with the immune system, other things may raise your chances of getting pernicious anemia. Your genes play a big part, but some people are born with genetic variation that makes their immune system more likely to attack the lining of the stomach. If you have family members with autoimmune diseases like type 1 diabetes or thyroid problems, your risk may be higher too. Age matters as well, and people over 60 get this condition more often.
Researchhas shown that pernicious anemia is closely linked to genetics and the immune system. Researchers analyzed the DNA of over 2,000 people with pernicious anemia and compared it to more than 650,000 people without the condition. They discovered several genetic markers that are much more common in those affected.
Three large European biobanks were used: the Estonian Biobank (EstBB), UK Biobank (UKBB), and FinnGen. In Estonia, 378 cases and over 138,000 controls were identified, with a disease rate of 0.3%. In the UK, 754 cases and 390,000 controls were found, with a rate of 0.2%. In Finland, researchers looked at a broader category called “Vitamin B12 deficiency anemia,” identifying 1,034 cases and 131,000 controls, with a rate of 0.8%. All studies applied a special analysis method that adjusted for factors such as age, sex, and genetics. The combined results from these populations were analyzed together in a meta-analysis to better identify genetic links to the disease.
The meta-analysis pinpointed five specific genetic variants strongly associated with pernicious anemia. These variants are located on Chromosome 1 (rs6679677), Chromosome 2 (rs12616502) , Chromosome 6 (rs28414666), Chromosome 10 (rs2476491) , and Chromosome 21 (rs74203920). Importantly, these findings were consistent across all three biobanks, confirming the genetic basis of this autoimmune form of vitamin B12 deficiency. The genetic markers are near genes involved in immune system function and other autoimmune conditions, suggesting that inherited immunological traits may increase the risk of developing pernicious anemia. Overall, this research confirms that genetics plays a significant role in pernicious anemia..
The primary approach to managing pernicious anemia involves restoring and maintaining adequate levels of vitamin B12, typically through intramuscular injections since the body cannot absorb the vitamin naturally due to the lack of intrinsic factor. Once B12 levels stabilize, some patients may switch to high-dose oral supplements under medical supervision. Treatment is ongoing and often lifelong, as the underlying absorption issue remains. In certain cases, antibiotics may be prescribed if intestinal bacteria are interfering with B12 absorption. Many individuals begin to feel better within days of starting treatment, although it may take several weeks for noticeable improvements. Long-term management generally requires regular monitoring and continuous supplementation to prevent recurrence and complications.
LifeDNA offers a personalized Vitamins and Supplements Report based on your DNA to help you understand your body’s unique nutritional needs. This includes insights on Vitamin B and D levels, giving you a clearer picture of what your body may need.
Vitamin B12 is one of the essential nutrients covered in these reports. Since the body doesn’t produce B12 naturally, it must come from food or supplements. Good sources include eggs, red meat, soy, nuts, seeds, shellfish, leafy greens, mushrooms, and bananas. While the recommended daily amount for adults is 2.4 mcg, higher amounts—up to 1000 mcg—may be needed for those with a deficiency. Fortunately, excess B12 is typically excreted through urine, making it safe to take more than the minimum.
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