What genetic tests for hereditary diseases are available? | The genetic examination

What genetic tests for hereditary diseases are available?

The principle of every genetic examination is DNA sequencing. Here, the DNA is broken down into its building blocks, the gene section to be examined is multiplied and then analyzed. Basically, a distinction can be made between genetic examinations that take place before birth (prenatal diagnostics) and examinations that take place in childhood and adulthood (postnatal diagnostics).

Prenatally, there are various examinations available, which will be discussed in more detail in the next section. But also postnatally there are different methods for DNA analysis. For example, a predictive test can be carried out to see whether a genetic change is present that could lead to the disease under investigation.

The disease can therefore be diagnosed before the outbreak. Accordingly, therapeutic measures can be taken early. The so-called heterozygote test describes a method where a healthy looking person is examined. The aim is to find out whether he/she is a carrier of a hereditary disease that could be passed on to the offspring.

What is a prenatal test?

A prenatal test is a genetic examination of the unborn child.It may be necessary to do this if genetic diseases are known in the family or if the previous examinations of the child indicate a genetic defect. On the one hand, a chromosome examination can be performed. Chromosomes are the carriers of the genetic material and can be wrongly combined during fertilization, resulting in malformations or even miscarriages.

Furthermore, tissue samples can be taken from the unborn child. For this purpose, amniotic fluid is taken, from which the cells of the child can be isolated. Subsequently, more detailed examinations are carried out.

In addition, the mother’s blood can also be analyzed molecular genetically. Here it is possible to see whether a trisomy 21 is present. Another alternative in prenatal diagnostics is the triple test.

Here the mother’s blood is tested for three specific hormones. On the basis of this, one tries to draw conclusions. However, this method is controversial.