What is the definition of genetic testing?
Genetic testing is a type of medical test that identifies changes in genes, inherited from our parents, which we then typically pass on to our children. “Mistakes” in our genes (called “mutations”) can manifest the disease, and genetic tests may be used to confirm the disease diagnosis.
A genetic test is an analysis of our DNA, genetic material in our cells, that gives us specific features and enables our body to perform various functions. A number of different methods exist for fast and reliable testing of our DNA, with sequencing (reading the order of DNA building blocks, called nucleotides), and deletion/duplication analysis (detection of large deletions or insertions within DNA/ genes) being the most common. In some diseases, especially in the field of lysosomal storage disorders, biochemical/biomarker testing allows an early diagnosis and continuous therapy monitoring
What are the benefits of genetic testing?
- For a lot of disorders, genetic testing is the only way to make an accurate diagnosis and help avoid additional unnecessary clinical investigations.
- Genetic testing can guide the clinician in choosing the most suitable therapy and support for the patient.
- A definite diagnosis can be a great relief to patients and families, especially if they have been searching for the answer for long time.
- In some genetic diseases good surveillance and early intervention can save the patient’s life (e.g. early diagnosis of hereditary cancer).
- The results of genetic testing may be useful for future family planning.
The accuracy of genetic test results is paramount. Major life decisions are often based on genetic test results. Therefore genetic testing should only be performed by accredited, high quality labs that regularly take part in external quality assurance schemes. Ideal patient care involves pre- and post-test genetic counseling to explain the range of options and possible outcomes, in order to obtain truly informed consent.
is performed in order to identify or rule out the mutation that causes the symptoms, and in a lot of cases to confirm the diagnosis.
is used when no symptoms are shown yet. But there is a probability of carrying the mutation and developing symptoms later in life.
is relevant for people who carry a mutation but are not affected themselves, although there is a risk for their children to be affected.
is important in families with a known genetic disorder when couples are planning to have children. Can be invasive and non-invasive.
At CENTOGENE, we perform the following types of genetic testing in house
- Hotspot testing – only tests for a few most common mutations
- Single gene sequencing – sequencing of the entire gene
- Deletion/duplication testing – longer stretches of missing or extra genetic material
- Repeat expansion analysis (fragment length analysis) – looks at repeats of nucleotide motives
- Next generation sequencing (NGS) panels – sequencing of groups of genes at once
- Whole exome sequencing (WES) – sequencing of all our genes (20,000) at once
- Whole genome sequencing (WGS) – sequencing of our complete genome including genes and the non- coding sequence (20,000) at once