What You Should Know About Genetic Testing
Genetic testing is becoming increasingly commonplace, both at home and at the doctor’s office. It’s possible to glean an incredible amount of information from your genetic code. Whether it’s having fun exploring your genetic root or potentially diagnosing a serious issue, here’s what you should know about genetic testing.
Basics of Genetics
Everything that occurs in our body is due to the “directions” written in our DNA. Our genes have a code based on the sequence of nucleotides. There are only 4 different nucleotides in DNA: adenine (A), thymine (T), guanine (G) and cytosine (C). However, the various combinations contribute to the vast array of cellular functions and variations between people. These long sequences DNA coil tightly together into chromosomes. Humans have 23 pairs of chromosomes in the nucleus of each of their cells.
If there is a suspected chromosome issue, a karyotype will be ordered. Cells are grown in an optimal, but sterile, environment. They are treated with chemicals so that the chromosomes can be best visualized based on the cell cycle. They are then fixed, stained, and analyzed via banding.
Molecular tests are used to look at gene-specific regions. Mutations in the nucleotide code can lead to pathogenic diseases. The specific gene is sequenced, where the exact nucleotides are “read”. From here, it can be determined if a mutation for that gene is present.
Types of Genetic Testing
Genetic tests types are broken down into the following categories:
- Newborn Screening
- Diagnostic Testing
- Prenatal Testing
- Preimplantation Testing
- Predictive/Presymptomatic Testing
- Forensic Testing
While the power of genetics has given us a great deal of information, there are limitations. One of the limitations is interpreting data. It’s still difficult to slough through all the data and make sense of everything in certain scenarios. Data analysis and computer algorithms are helpful but haven’t been fully perfected just yet.
Additionally, it is possible to find variants of unknown significance (VUS). This occurs when the results yield something that is not normal, but it’s not known if it causes disease either. With additional research over time, it is possible that a VUS will eventually become understood.
Most of the risk involved with genetic testing is emotional. Finding out you, or potentially your children, have genetic abnormalities can be difficult and stressful. It is essential that you speak with a genetic counselor before having the tests performed to ensure you understand the potential outcomes.
All in all, genetic testing is a valuable tool that helps to diagnose a variety of medical issues. It can be used across a large array of specialties and help people of all ages. With proper foresight and the expertise of a genetic counselor, getting the right test for your specific situation has never been easier.