Huntington’s gene contains a specific region that, in affected individuals, is expanded.
In all people, DNA stretching contains a pattern called "trinucleotide repetitions". Nucleotides are the building blocks of DNA and are indicated by the letters G, C, A and T. In many people, the CAG repetition pattern is present no more than 30 times or less, while in case of disease, it is present for more than 36 times. By analyzing the person's DNA and counting the number of CAGs, it is possible to know if that individual will develop Huntington's disease.
It is possible to know if a person is a carrier of the mutation through the genetic test, which consists of a simple blood sample.
The minimum age required for genetic testing in a person without symptoms is 18 years.
The decision to take the test is personal and cannot be taken lightly. A person at risk cannot be forced to know his or her destiny in advance..
It is important that people who intend to undergo the test do so in a specialized center, which provides preliminary sessions and interviews with various professional figures: geneticist, neurologist, psychologist. The discussion of the result and the follow-up at a later time complete this process.
The purpose of the preliminary sessions is to ensure that the potential implications of one’s genetic state are completely understood, that the choice is made in full awareness and that patients are prepared to receive a positive result of the test.
It is important to remember that, at the time of testing, it is not yet possible to determine when the disease will begin, how its course will be and what level of severity it will reach.
Individuals who tested positive can stay healthy for a long time, as the symptoms can occur even many years later.
If you intend to plan a family, the couple can request the prenatal test of the fetus or think of a pre-implantation (which in Italy, however, is not currently executable).