It is a test performed for knowledge of chromosomes, genes or proteins, which can be associated with disease, predisposition to disease or paternity studies.

Our organism consists of cells that contain 46 chromosomes in their nucleus (22 pairs of autosomes and one pair of sex chromosomes (XX – women, XY – men)). Chromosomes contain genetic information encoded by a sequence of nucleotides that are the basic unit of DNA.

Genes are regions of our DNA that encode proteins (responsible for all of our characteristics). Each gene has two copies, one on each pair of chromosomes.

A mutation is a permanent change in the genetic code, by exchange, deletion or insertion of nucleotides in a gene, whether or not it can change the final protein.

You should be followed up in a specialist consultation appropriate to your pathology as well as in Medical Genetics consultation.

The first to monitor your pathology, prevention, anticipatory care and prophylactic measures. The second is to assess the mechanisms and prognosis of the disease, as well as the risks for the remaining members of your family and the limits and possibilities of resorting to prenatal diagnosis or pre-implantation genetic diagnosis (DGPI).

When a mutation is present only in one of the pairs of a non-sexual chromosome and is still sufficient to cause disease, it is said that we are facing an autosomal dominant disease. In this type of inheritance, there is a 50% risk of being transmitted to offspring (eg, Marfan syndrome).

When it is necessary for both pairs of the non-sexual chromosome to have the mutation, we are facing a disease with autosomal recessive heredity. In these cases, individuals with only one mutation are called carriers, or heterozygotes, and these, in most cases, do not have a disease. The risk of disease transmission to offspring is 25% for couples where both elements have the same genetic disease (eg, cystic fibrosis).

Heredity linked to the X chromosome has particular characteristics because the genes on these chromosomes have 2 copies in women (XX) and only 1 in men (XY). Therefore, in diseases linked to recessive X chromosome, male individuals are sick and females are carriers, with a 50% risk of transmitting the change to offspring (to daughters as carriers and sons as sick). Dominant X chromosome-related diseases are usually lethal in males and manifest in females. Examples of the former are Duschenne Muscular Dystrophy and the latter of Incontinentia Pigmenti.

It is a test carried out on a healthy person with family members in 1st degree heterozygotes/carriers or with a certain autosomal recessive inheritance pathology (ie, in which only one of the chromosome pairs has the mutation).

Heterozygous studies can only be performed in the context of a Medical Genetics consultation.

Germline mutations are mutations present in all cells of our body. They can be screened in lymphocytes, by sample of peripheral blood.

Somatic mutations are mutations that occur only in certain tissues and have to be studied in cells of that tissue. The samples are usually fibroblasts (by skin biopsy) or tumor piece (by surgical biopsy, in cancers).

The predictive test is performed on healthy people with 1st degree relatives affected by a syndrome of predisposition to disease (ex: BRCA1 and BRCA2).

Predictive studies can only be performed in the context of a Medical Genetics consultation.

It is a test carried out on a healthy person with first-degree relatives with late onset syndrome (ex: Huntington’s disease, PAF).

Pre-symptomatic studies can only be performed in the context of a Medical Genetics consultation.

When a direct family member has a positive result in a genetic test, the family members/healthy people should be referred to a genetic consultation to assess the risk of heredity and the indication or not to perform a genetic study.

If you have a family member with an identified genetic disease (or not), we advise you to visit a genetic consultation, where the doctor can consequently indicate the necessary tests for diagnosis.

Tests ordered at the hospital level are paid for by the hospital. At the outpatient level, there is no convention with the SNS, so genetic tests will have to be paid for by the user or possibly by the insurer in the case of some health insurance and for some tests.

Yes, as long as requested by a doctor specializing in Clinical Genetics.

No, the legislation requires that genetic diagnostic tests be carried out only with a medical request, which can be issued by a specialist doctor depending on whether it is a patient, or by a geneticist doctor in the case of non-sick relatives.

The prescribing physician receives the result of the analysis, and transmits it to the user, as well as the need for genetic monitoring or not.

Yes, at GenoMed there is a harvesting room, which works at the following hours: Mondays from 9 am-1pm.

Harvesting for genetic testing does not require marking. Crops for paternity tests preferably with marking.

It is not necessary to harvest on an empty stomach. The harvesting room is located in the Egas Moniz Building, behind the Santa Maria Hospital.

To perform a genetic test, it is necessary to send:

• Sample (type of sample is specified with each test);
• Informed consent of the user;
• The GenoMed requisition, duly filled in with the user’s data, the type of test required, date and time of collection.
• Term of responsibility of the requesting entity “Private or public hospital”.

All of these documents are available for download here.

The legislation that regulates the matter of genetic tests, is Law No. 12/2005 of January 26, qualified by Decree-Law No. 131/2014 of August 29.

Diagnostic tests involve a medical request, and preferably follow-up by a geneticist after receiving the results, as these may have implications for the user’s health. Genoration non-clinical tests focus on genetic variations that have no clinical significance, so the results have no implication or translation for the user’s health.

Yes, GenoMed has a partnership with Dr. Diana Antunes, a geneticist, who makes appointments at predefined times.

For more information or to make an appointment contact genomed@genomed.pt or dianaantunes@medicina.ulisboa.pt