Polyclinic

Sequencing (Exome/Genome/Trio)

This technique is applied in the healthcare sector to identify genetic variations and is used in research. Many of the mutations known to cause diseases occur in exomes. Exome sequencing is considered an effective technique for identifying mutations that cause diseases. Ongoing examination of exomic and genomic sequences will assist in the diagnosis of diseases in the future. Additionally, this method helps determine whether new genetic variations are associated with health conditions.

Exome sequencing not only enables the identification of variations in the coding regions of several selected genes but also in every gene. Exome sequencing has proven successful in identifying new causative mutations for unknown diseases through technology focused on the coding regions of the genome. This method has the potential to increase the ability to take preventive action before the disease develops or to begin treatment for an undiagnosed disease. In this sense, exome sequencing allows for efficient identification of coding variations across a wide range of applications, including genetic diseases and cancer. This technique is one of the next-generation sequencing methods aimed at identifying genetic diseases that cannot be diagnosed with clinical and laboratory tests.

Interpretation of exome sequencing data, in accordance with clinical findings and family history, is carried out in light of current scientific data. Currently, out of more than 20,500 genes in humans, 8,000 are known and associated with existing diseases.
The diseases/findings being investigated in the patient are assessed in relation to findings in the literature cases, and the identified variations are analyzed using pathogenicity assessment tools (SIFT, PolyPhen-2, MutationTaster, MetaLR…) and reported according to the ACMG (American College of Medical Genetics) criteria. As a result of these investigations, possible treatments for the patient’s diagnosis are determined, and with family screening, individuals at risk for diseases/carriers can be identified, which may lead to disease prevention in future pregnancies. Results from these analyses are usually completed within 1-2 months.

In Exome Sequencing:

• Analysis of 20,500 gene sequences
• Copy number changes
• Evaluation of clinically significant HLA variations.

In the analysis:

• Variations that may explain the clinical findings of the patient
• Variations that could be important and treated in the future, at the individual’s request.

The analysis consists of four phases:

• Data analysis in the laboratory
• Bioinformatics
• Clinical assessment
• Confirmation

For quality analysis:

• Resolution of data generated from the analysis
• Detailing of data in bioinformatics, quality assessment, and identification of high-risk variations
• Review of the process by a doctor with experience in patient review and evaluation
• Confirmation of obtained data, family screening, and necessary additional analyses for pathogenicity assessment of identified variations (RNA sequencing, Western Blot, X-ray, biochemistry, etc.)
• Review of data for patients with unclear or undiagnosed diseases at appropriate intervals and re-interpretation in line with current literature.

Analyzing:
Analysis is the process of transforming obtained data into a clinical report that is useful for the patient and clinician. Reports are prepared that include accurate interpretations of variations selected from a data set to provide the necessary information for the clinician.