WES TEST

Why are TWO genetic consultations necessary when performing a WES test? 

A pre-test consultation is necessary for the geneticist to assess and describe the Patient’s symptoms. A correct description of the symptoms has a great impact on the analysis, which is always individualised and directed towards finding the cause. On this basis, areas of genes are selected to be 'scanned’ in great detail.

Consultation with a geneticist after the test is crucial. The doctor discusses the results obtained with the Patient in detail and makes recommendations regarding further management.

Therefore, we should consider TWO GENETIC CONSULTATIONS as an integral part of any WES test.

The extent of gene alterations checked can vary depending on the used technology. It is a bit like blood tests. You can do a basic blood test, but this will not provide a complete picture of the Patient’s health. In addition, many other parameters can be tested from the blood, e.g. vitamin or micronutrient levels, cholesterol, metabolites, etc. In the same way, different things can be checked in genes The basic WES test checks exons – the best known parts of genes that influence the development of congenital diseases. However, there is already technology that checks introns – equally important parts of genes, but much more difficult to check. The best WES test (WES COMPLEX) is able to check them too, increasing the chance of knowing the cause of symptoms by up to 11% – which is a lot.

Additional gene parameters that can be checked in a WES test include, for example, larger losses or excesses of DNA material (known as copy number variations – CNVs) or mitochondrial DNA, which is very important for diseases related to the nervous system (e.g. epilepsy).  It is therefore worth having an idea of the scope of the chosen test before choosing.

In addition to checking genes, the most advanced WES -WES COMPLEX tests also check the levels of metabolites responsible for certain metabolic diseases. By checking selected enzymes and biomarkers, it is possible to confirm whether or not a particular disease is developing in the Patient’s body and the stage of the disease.

Another important thing when choosing a WES study are the databases. Whether they are paid or only free databases can determine the outcome of the study. The databases are kind of like a DICTIONARY for those performing the WES analysis. When a change in a particular gene is detected in a Patient, the diagnostician checks the meaning of the gene – just as one checks the meaning of a word in a dictionary. What is important is which 'dictionary’-base the diagnostician has access to. Free databases do not have all possible information – all 'words’. They are therefore incomplete. Only the use of paid databases (e.g. HGMD) guarantees access to all the information that can affect the Patient’s outcome.

Low-cost WES tests are usually performed on the basis of FREE databases. Using only these has a real impact on whether the result will be complete. For example, in a free database, a variation detected in a child may not exist and so will not be reported on the test result, whereas in a paid database this variation will be explained and, on that basis, should already be indicated on the result.

For the Patient, the fact that the Laboratory uses paid databases means that the chance of diagnosis and help for the child is increased.

A very important aspect when choosing a WES test are the certificates that the Laboratory performing the analyses has. Why are certificates so important? Because they prove that the Laboratory follows procedures and high standards that ensure the reliability of the results. For the Patient, this simply means confidence in the diagnosis and that nothing has been overlooked.

If the WES test is performed in a certified Laboratory, you can be sure that an external institution (e.g. the (European Molecular Genetics Quality Network, EMQN) has verified that the analysis process is set up and applied according to recommendations and standards. External institutions only issue a certificate once all the required standards have been met. Obtaining certification is not easy – it requires implementation of rigorous procedures and their maintenance, but laboratories choose to make the effort because it guarantees the quality and reliability of the results.

WES testing at the TestDNA Laboratory can be arranged in the shortest possible time. The Patient waits a maximum of about one week for a consultation with a geneticist. Then the time from the arrival of the sample in Poland to the issuing of the result is about 6 weeks. After the result is issued in a maximum of about one week, a consultation with a geneticist takes place, who discusses the result with the Patient.

The sample for the test is a dried blood spot. To collect it, it is enough to gently puncture the Patient’s finger or foot; the process is non-invasive and painless and there are no contraindications.

A dried blood spot is a very durable sample, which means that there is no problem to transport it from the collection site to the Laboratory. The sampling can even be performed on a newborn baby. In addition, it is worth noting that the number of samplings is minimised as much as possible, which significantly increases Patient’s comfort.