Healthy Living

New DNA Test May Identify Celiac Disease

New DNA Test May Identify Celiac Disease

As far as healthy living and dieting are concerned, it seems that a gluten-free diet is the latest fad. Invite some friends to dinner, and it will be obvious that at least one of them will have issues with some of the dishes, probably due to gluten availability. This happens because some people suffer from gluten intolerance and others from celiac disease. A study showed that parents tend to diagnose allergies in their children. However, when appropriate allergy test is conducted, their children didn’t suffer from anything. What could this mean?

Gluten intolerance or celiac disease

Perhaps some people have decided that they have celiac disease and eat a gluten-free diet only. Sometimes, people haven’t understood that there is a difference between gluten intolerance and celiac disease. These people also are not aware that it might come at a cost when avoiding gluten: a gluten-free diet might lack essential nutrients and minerals. Apart from that, a gluten-free diet sometimes leads to weight gain. Usually, people find other ingredients in gluten-free products which add to overall salt, calorie and fat content. These extra ingredients are added to improve flavor and make the diet as tasty and palatable as their counterpart that contains gluten. For instance, flour is replaced by potato starch when used in gluten-free products, but the products are higher in calories.

Also, another study showed that about one-third of NCGS patients still had symptoms after they had given up gluten. The reasons may be due to poor dietary, diagnostic error, compliance or any other reason, and no one knows why this happens. However, it shows that we don’t get gluten.

Celiac affects about 1% of the world population. The disease is more common than rheumatoid arthritis or lupus. Celiac affects any part or organ of our body, including our digestive system. It is triggered by a mixture of proteins in derivatives, barley, wheat, and rye, as well as the eating of gluten. Research indicates that environmental factors are associated with it.

Twin studies and family studies have proven that celiac disease is hereditary. Celiac disease has far wider reaching consequences and side effects. Diagnosing the condition can be hard, but a genetic test could be the answer.

Gluten problem

Gluten is a protein found in many derivatives and products including flour. Some people are either gluten intolerant or suffer from celiac. Sometimes gluten intolerance is called gluten sensitivity or non-celiac gluten intolerance. Being celiac is serious than having gluten intolerance. Some people are gluten intolerant but don't have celiac disease. A person with celiac may suffer as the immune system attacks the intestine and damages intestinal villi which are crucial in the absorption of nutrients such as water soluble vitamins. It might result in non-absorption and malabsorption of crucial nutrients leading to malnourishment.

What is the cure?

Curing celiac involves eliminating gluten from medicines, diet, etc. A person who is gluten intolerant can consume gluten occasionally without discomfort. However, that person needs to avoid gluten.

Testing for celiac disease

When someone eats pasta or bread, and they feel bad, how do they know what they are suffering from? The best way to know is by carrying out a genetic predisposition test. The test will show if the person carries genes known to be associated with celiac disease.

Apart from the genetic testing, the blood antibody screening test is another test applied widely. The two methods are different from each other. The blood test also known as serology test concentrates on the level of Tissue Transglutaminase Antibodies in blood. This antibody is triggered as the body responds to gluten ingestion. When the result is positive, then it means the person tested suffer from celiac disease. For the test to be successful, the person tested needs to follow a diet that contains gluten. A person with celiac disease will suffer discomfort. Those on gluten free diet will have to introduce some gluten so that the level of antibodies might increase in their blood. When the level of antibodies is low, the test might report false results.

The genetic test is very different from the antibody test. In this method, mouth swabs are used in collecting a DNA sample. To understand celiac disease, celiac DQ (specifically DQ8 and HLA DQ2) genetics needs to be checked. Genes found on chromosome 6 is responsible for this disease. Human leukocyte antigen is found on chromosome 6. There are other genes responsible for celiac disease, but the HLA-DQ8 and HLA-DQA2 genetic variations are the main ones. HLA-DQ8 gene is responsible for about 5% of the patients while HLA-DQ2 gene is responsible for about 95%.

The antibody test may show if the person tested is developing celiac or at high risk of getting the disease. However, it doesn’t mean that the person tested is celiac at the time of testing. The genetic test depends on polymerase chain reaction which is a molecular biology technique. This technique helps in amplification of extracted DNA.

Unlike the antibody test, a person testing for celiac disease doesn’t have to follow gluten-free diet since the genetic test only looks at the genes. When the genetic DNA test shows the results, it's either someone is celiac or needs to avoid gluten. When the results are negative for both HLA-DQ8 and HLA-DQ2, then it means that the person tested has 99% possibility of not developing celiac disease.

What is the perfect celiac test?

HLA genetic testing isn’t an ideal way to test if you are celiac or not. There isn’t an ideal test. Doctors recommend a combination of several tests. HLA genetic testing only shows the level of predisposition, but the chances are that the person testing might not have developed celiac at the time of screening. However, this test is useful when excluding celiac disease when a doctor suspects it. A good screening test to start off with is blood antibody test.

Endoscopic biopsy is the only testing that is diagnostic as the procedure will determine the extent of damage that the disease has caused. It will also determine if the damage is consistent with the disease. This procedure uses an actual intestinal tissue sample in the analysis.

Hidden gluten

Having a gluten-free diet isn’t an issue when two things are known: a test is required to know if celiac exists and great attentions need to be paid to gluten-free products. Someone can self-diagnose themselves with gluten intolerance or celiac. When a person is diagnosed with celiac, what should they avoid? Doctors usually give people what to avoid but here is a short list of the things to avoid.

Cookies, cakes, bread crackers, pasta and other baked delights have gluten. However, gluten is hidden in many medicines and foods. For instance, soy sauce contains gluten since it is made with soy, salt, wheat and other ingredients. Therefore, sushi bought in a restaurant could be a problem.

Ready-made soups are tasty, convenient and quick. It contains high gluten as well. Most people also love ice cream, but sometimes it might contain gluten. The most obvious one is the biscuit chip ice cream. Other foods that contain gluten are sausages, cubes, preserves, dietary supplements, and toothpaste.

Most people believe that oats contain gluten. This misconception isn’t true. In the natural taste, oats don’t contain gluten. However, oats are processed in facilities that process other products and cereals. These other products and cereals contain gluten. It means that it will contaminate the oats.

Sources

http://www.zmescience.com/medicine/nutrition-medicine/celiac-gluten-dna-test-08032017/

Key Takeaways

  • One test for gluten, a blood test also known as a serology test, concentrates on the level of Tissue Transglutaminase Antibodies in the blood. 
  • The genetic test is very different from the antibody test. In this method, mouth swabs are used in collecting a DNA sample. 
  • Doctors recommend a combination of several tests.