Cheek test: what it is, benefits and how it is done

In Brazil, every newborn has the right to perform four tests of neonatal screening. They identify the increased risk for the development of early-onset congenital diseases that can interfere with development and even lead to death.

With early diagnosis, it is possible to carry out the specific treatment of these diseases — reducing or avoiding sequelae that compromise quality of life. The screening includes the basic foot test, eye test, ear test and little heart test.

Know more: 7 exams to do on the baby before leaving the maternity hospital

There are also other complementary neonatal tests that can be performed soon after birth. With the same premise of detecting and controlling disorders manifested in the first years of life, the new method that is emerging in Brazil is the cheek test.

What is the cheek test?

The cheek test is a genetic neonatal screening that, through the sequencing of the newborn’s DNA, identifies changes in more than 380 genes associated with genetic and congenital diseases that can manifest in childhood, all with treatment already available in Brazil.

“The test is considered one of the most comprehensive to complement newborn screening. It is the test that delivers quick results and can reduce or prevent sequelae and even early death”, explains Rosanelle Araújo, geneticist at Grupo Sabin Medicina Diagnóstica.

The test, already available in Brazil through the private network, was developed and marketed by the Brazilian laboratory Mendelics.

How does the cheek test work?

Being a genetic neonatal screening, the test allows directly investigating the newborn’s DNA, looking for changes that may indicate the emergence of diseases even before the manifestation of symptoms.

For this, the baby sample is analyzed with a method called Next Generation Sequencing (NGS), which allows for faster sequencing of DNA and RNA structures.

“It is in the DNA that we store the information for the production of proteins, responsible for our characteristics and functionalities of our body”, explains Rosanelle.

According to the specialist, the cheek test is able to identify:

• Inborn Errors of Metabolism;

• Neurological diseases;

• Immune diseases;

• Hematological diseases;

• Kidney diseases;

• Endocrine diseases;

• Gastrointestinal and liver diseases;

• Lung diseases;

• Eye diseases;

• Deafness.

Also read: Enzyme in blood may indicate risk of sudden death in babies

How is the cheek test done?

The collection of the analysis material is done with the aid of a cotton swab (swab), which is passed on the inside of the child’s cheek. Quick and painless, the exam lasts about a minute and can be done as soon as the baby is born or up to one year of age, in the maternity ward or at home, by the parents themselves.

Before the collection, Rosanelle explains that the baby must be thirty minutes of complete fasting, without ingesting food and liquids or inserting any objects into the mouth.

After that, the sample is sent to a clinical analysis laboratory, where the DNA will be isolated and sequenced to then be aligned with the child’s genome.

Benefits of the cheek test

One of the biggest advantages of the cheek test is that, once the baby’s DNA is analyzed, it is possible to identify the risk of the disease even before any clinical signs.

Early diagnosis allows the diseases detected to be treated from the first days of life, reducing or avoiding sequelae and even the death of the child.

“It’s an exam that adds a lot to neonatal screening, a fundamental care for the child’s quality of life”, adds Rosanelle. The most recommended is that it be performed soon after birth or as soon as possible.

Does the cheek test replace the heel prick test?

Not. According to Rosanelle, although the test is an important ally in the early identification of disorders, it does not replace the heel prick test. “There are diseases that do not have genetic causes and, therefore, it is recommended that both tests be carried out”, adds the specialist.

In addition, Rosanelle points out that the genetic test of the cheekbone can supplement information and help confirm diagnostic suspicions identified from the conventional newborn screening test.

“These are exams such as the foot, ear, tongue, little eye and little heart and, now, the cheek, which complement each other and allow a comprehensive assessment of the baby’s health in the first days of life”, he concludes.

Is the cheek test really necessary?

It is important to understand that, as it is a more comprehensive test, all diseases detected by the cheek test are rare, with a incidence of 4%. The main ones and with the highest incidence are still those of the heel prick test.

Also, the cost of testing should be a factor to consider. It is only available on the private network, and can cost from R$800 to around R$1,200.

Another point of discussion is that the results can bring about changes in the way parents take care of their children – generating unnecessary spending and even too much anxiety. Remembering that, because it is a screening test, it does not determine a final diagnosis.

It is essential that, before reaching a decision, parents consult a specialist, who will be able to indicate whether the test is really necessary and follow the case with the family.