Whole Exome Sequencing (WES)

Whole Exome Sequencing method aims at examining all of the regions of the human genome called exome. Through this method, similar to other NGS tests, it has been possible to perform these tests fast with reasonable costs in exome sequencing studies.

Properties of a whole-exome sequencing technique

  • A small amount of blood sample is sufficient for study
  • Examination of all the exomas of a sick child, and parents
  • Quick results (~ 1.5-2 months)
  • Low costs compared to the scope of the test
  • The fact that it can also be used in patients whose clinical diagnosis are not made *

*The situation that standard chromosomal analyzes are performed primarily for suspected cases of the genetic disease but not diagnosed, the aCGH application should also be recommended if it is normal. If the aCGH test turns out normal, "whole exome sequencing" can be recommended as the last step.

One of the most important advantages of exome sequencing is that it offers a chance to diagnose a disease that can not be diagnosed clinically. There was not any other proposal for this kind of disease because there was not anything more than genetic science could do before. After whole-exome sequencing is started to be used by a lot of patients whose clinical diagnosis was not previously made or whose test results were normal after pre-diagnosis. It also allows the identification of sick embryos by genetic examination in the IVF stage for parents, who wish to be able to perform prenatal diagnosis in new pregnancies of patients having sick children.

At our center, detailed disease information, which has a very important role in the accurate evaluation of exome sequencing results, is taken before the analysis for the family tree. Then, exome sequencing is performed for all of the blood samples of parents and sick children. The obtained data are evaluated in line with information received from the family. If the sick child is not alive, if the autopsy has been done, studies carried out on the babies' tissues stored in the pathology laboratory, if tissues have been previously stored, studies carried out on blood and DNA samples. If there is no sample of the sick person, exome sequencing is performed only for the parents and the results of the study are evaluated only for autosomal recessive diseases and the disease is tried to be diagnosed.