Genetic testing - what does it do for a person

Genetic testing deals with the part of a person's health that no other test can tell us anything about. Thanks to them, we are able to "predict" which diseases a person may develop.

DNA tests are usually carried out when:

• we have a family member with a hereditary genetic disease and we want to find out whether we might also have it,
• we have symptoms of a genetic disease and need to confirm the diagnosis,
• we know we have a disease, but are afraid to pass it on to our offspring.

Genetic testing is used today, for example, in the diagnosis of diseases such as Huntington's disease, cystic fibrosis, Duchenne muscular dystrophy or Down syndrome. There is also a whole range of so-called predisposition tests behind genetic testing, e.g. for breast or ovarian cancer. Knowing that you are at increased risk of contracting a disease is very important, because instead of treating it, you can then try to prevent it from occurring. Recently, genetic testing has also been increasingly used in the diagnosis of coeliac disease, which is a very good example demonstrating the superiority of genetic testing over other methods of disease diagnosis.

Coeliac disease - a disease of children and adults

Coeliac disease (visceral disease) is a genetic disease caused by an abnormal reaction of the autoimmune system to the gluten consumed. Once this protein enters the body, the immune system begins to secrete antibodies that damage the villi in the small intestine. Without functioning villi, the body does not receive sufficient amounts of vitamins and minerals, as it is these small structures that are responsible for their entry into the body. Over time, therefore, nutritional deficiencies occur, and with them a range of unpleasant symptoms.

How celiac disease progresses depends on the age of the patient. Because it is a condition that occurs in both children and adults. In younger children, the symptoms mainly revolve around the digestive system - these are usually diarrhoea, vomiting and abdominal pain. In older ones, mood swings, oral aphthae or fatigue may occur. Nutritional deficiencies can also stunt growth. In adults, on the other hand, the disease concentrates on all other systems apart from the digestive - the skeletal, causing frequent fractures, the reproductive, leading to infertility, or the haematopoietic, increasing the tendency to bleed.

Celiac disease is a condition that only occurs in genetically predisposed people. It appears in carriers of the HLA-DQ2 and HLA DQ8 genes.

DNA test for coeliac disease or serological test - which to do?

It is best to do both, with DNA analysis being the best place to start. Simply finding the symptoms of coeliac disease is not enough to make a diagnosis. It is then best to reach for a quick and convenient DNA test for coeliac disease. It will determine whether the person tested has the genes that cause the disease. If not, it means that he or she does not have the disease and will never have celiac disease again. This is where all the diagnostics end. If, on the other hand, the test reveals the presence of genes, the patient must undergo further tests to determine whether or not celiac disease is active in the patient. For this purpose, a serological test is performed to detect the antibodies present in visceral disease. Only a positive result of both tests and the presence of symptoms of the disease allows it to be confirmed.

It is worth remembering, however, that serological tests may be ineffective in the case of children under two years of age. Their immunity is still developing and antibodies characteristic of coeliac disease may be absent in them. It is therefore all the more advisable to immediately resort to DNA testing and, in the event of a positive result, to consult a doctor about further diagnostics.

Genetic testing - has it changed the face of modern medicine?

Definitely! We do not even realise how many diseases are caused by mutations of specific genes (or the mere presence of such mutations). Fortunately, thanks to genetic testing, we are now able to quickly (and, against all appearances, for very little money) identify these and then take effective action. Perhaps the time will come when every child will undergo preventive genetic testing immediately after birth to determine which diseases he or she is at risk of developing. This knowledge, in turn, will give him or her the chance to avoid risks and stay healthy for years to come.