5 questions about genetics

Proven content

Is it true that …

… is it worth doing a genetic test? TRUE

But it’s best to know why. The cost of performing a genome-wide test is quite high. Some choose to do this comprehensive study to make sure their genome is of high quality. Most often, however, they look for an answer to a specific question – can a genetic disease in someone in the family affect my life or the lives of my children. In such a situation, however, it is best to examine the genes of the sick person. It is then much easier and cheaper to find the cause of the genetic disease – you know where and what you look for in the genome. Only later should a similar mutation be looked for in a healthy person to determine whether he is at risk of the same disease in the future.

… can you cure yourself of a genetic disease? NOT TRUE

Not yet. Genetic information is like a blood type, you have it for life. If it is incorrect, it causes the so-called a mutation that sometimes results in a genetic defect that affects the quality of human life. For now, it is not possible to easily replace the defective genetic information with the correct one, although scientists and doctors are working hard to “repair” defective genes in the near future. And they are getting closer to success. Still, their biggest problem is how to get the correct genetic information to the right place in the genome.

Gene therapies are experimental treatments and are sometimes successful. Recently, the world has heard that several children have been cured of severe genetic defects by using a mutant HIV virus to transport genetic information. A characteristic feature of viruses is that they easily penetrate into human cells and build their own genetic information into the cell nuclei. It is enough to trick the virus by implanting it with the correct human genetic information and sending it to deliver it to the right place. Scientists have high hopes for the HIV virus – its advantage is that they know exactly where they will drop their genetic baggage. With its help, it is possible to treat only certain diseases and only at an early stage of life, before the genetic defect has time to cause irreversible damage to the body.

… the older the woman is, the more likely she is to give birth to a child with a genetic defect? TRUE

Every woman is born with a ready-made set of eggs. It does not produce new ones. Each of these cells is dormant for years to be fertilized. Over time, the eggs are increasingly exposed to damage to the genetic information they contain. Hence the risk that after 40 years of waiting, they will develop a genetic information defect, which will cause a genetic defect in the child.

It is different with men. Their reproductive cells, the sperm cells, are formed continuously throughout life, and age has no effect on the chromosomal aberration in the sperm. Therefore, even in old age, they most often become fathers of healthy children.

… in old age it is not worth doing genetic tests? NOT TRUE

There is no limit on which we stop taking care of our health. On the contrary, medical practice shows that the older a person is, the more wise they are. Hence, among the sick but also healthy people visiting genetic doctors’ offices, a large group is people in their sixties. They want to know if their ailments are caused by a genetic mutation and whether they are at risk of diseases such as Alzheimer’s, Parkinson’s or cancer in their old age. Especially if these ailments affected someone from their family. Such knowledge will help them, if not prevent, at least delay the development of the disease. For example, in the case of genetic background of thrombosis, they can take preventive medications and lead an active lifestyle at the same time. Knowing about the risk of diseases such as Alzheimer’s and Parkinson’s will encourage them to exercise – body and mind, and also allow them to prepare for situations when they need care. In cancer, if it is known that it is conditioned by a specific and discovered genetic mutation, it is easier to select drugs. You can also warn children and grandchildren of a hereditary risk, and thus make them take preventive measures to prevent the development of the disease in them.

… genetic testing is very expensive? TRUE / NOT TRUE

A genetic test covering the entire genome is indeed expensive (PLN 8-12 thousand). Most often, however, it is not needed. When we look for the genetic cause of ailments in ourselves or a family member, a lot depends on whether we are looking for a known and common mutation in the population, in the same small gene, or we are looking a little blindly by searching a large gene or even several genes. Most often, we deal with the first situation – a genetic test is usually a study of a minimal fragment of the genome, which is to answer a specific diagnostic question. For example, am I at risk of thrombosis, breast cancer? Such a test costs several hundred zlotys (the cheapest for thrombosis – about 200 zlotys). And it is cheaper than looking for the causes of the disease by biochemical diagnostic tests. However, if a patient has the misfortune to get sick due to scattered mutations in a huge gene, e.g. in the case of type 1 neurofibromatosis, as many as 58 fragments in the great NF1 gene have to be searched. Then the cost increases to several thousand zlotys.

Tekst: Zuzanna Matyjek

Consultation Monika Jurkowska, MD, PhD, Krystyna Spodar, MD, PhD, NZOZ Genomed