What genetic counseling is, what it is for and how it is done

Genetic counseling, also known as genetic mapping, is a multidisciplinary and interdisciplinary process carried out with the aim of identifying the probability of the occurrence of a certain disease and the chances of it being transmitted to family members. This examination can be done by the carrier of a certain genetic disease and by his family members and from the analysis of genetic characteristics, prevention methods, risks and treatment alternatives can be defined.

Genetic counseling has several applications, which can be used in pregnancy planning or prenatal care, to check if there is any chance of alteration in the fetus, and in cancer, in order to assess the chances of cancer occurring and establish the possible severity and treatment.

What is genetic counseling for

Genetic counseling is done with the aim of verifying the risk of developing certain diseases. This may be possible from the analysis of the person’s entire genome, in which any type of alteration that may favor the occurrence of diseases, especially cancer with hereditary characteristics, such as breast, ovary, thyroid and prostate, for example, can be identified.

In order to carry out the genetic mapping, it must be recommended by the doctor, in addition, this type of test is not recommended for all people, only for those who are at risk of developing hereditary diseases, or in the case of marriage between relatives, for example, called consanguineous marriage. Know the  risks of consanguineous marriage.

How is done

Genetic counseling consists of carrying out tests that can detect genetic diseases. It can be retrospective, when there are at least two people in the family with the disease, or prospective, when there are no people with the disease in the family, being done with the aim of checking whether there is a chance of developing a genetic disease or not.

Genetic counseling takes place in three main stages:

  1. Anamnesis:  at this stage, the person fills in a questionnaire containing questions related to the presence of hereditary diseases, problems related to the pre or postnatal period, history of mental retardation, history of abortion and presence of consanguineous relationships in the family, which is the relationship between relatives. This questionnaire is applied by the clinical geneticist and is confidential, and the information is for professional use only and with the respective person;
  2. Physical, psychological and laboratory  tests : the doctor performs a series of tests to check if there are any physical changes that may be related to genetics. In addition, childhood photos of the person and his family can be analyzed to also observe characteristics related to genetics. Intelligence tests are also carried out and laboratory tests are requested to assess the health status of the person and his / her genetic material, which is usually done through the examination of human cytogenetics. Molecular tests, such as sequencing, are also performed to identify changes in the person’s genetic material;
  3. Elaboration of diagnostic hypotheses:  the last stage is performed based on the results of physical and laboratory exams and analysis of the questionnaire and sequencing. With this, the doctor can inform the person if he has any genetic alteration that can be passed on to the next generations and, if passed, the chance that this alteration has to manifest and generate the characteristics of the disease, as well as the severity. 

This process is done by a team of professionals coordinated by a Clinical Geneticist, who is responsible for guiding people in relation to hereditary diseases, chances of transmissibility and manifestation of the diseases.

Prenatal genetic counseling

Genetic counseling can be done during prenatal care and is indicated mainly in case of pregnancy at an advanced age, in women with diseases that can affect the development of the embryo and in couples with family ties, such as cousins, for example.

Prenatal genetic counseling is able to identify the trisomy of chromosome 21, which characterizes Down’s Syndrome, which can help in family planning. Learn all about Down syndrome. 

People who wish to have genetic counseling should seek out a clinical geneticist, who is the doctor responsible for the guidance of genetic cases.

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