A <genetic test> uses <genomic sequencing> to ‘read’ your DNA. Your chromosomes are made up of DNA, and contain your genes. Each cell has an almost identical collection of all of your DNA, which can be called your <genome>. Four subunits, called nucleotides, are repeated in long, unique sequences, and make up the large DNA molecule. When we ‘read’ DNA sequences, these nucleotide building blocks are represented as ‘A’, ‘T’,‘C’, and ‘G’ so that scientists and their computers can analyze DNA data more easily. DNA analysis, used by genetic tests, can provide information about your risk of hereditary cancer. Here is what raw genomic data looks like:
A genetic test is one of the many different ways to be screened and tested for cancers and cancer risk. Getting a genetic test allows scientists to ‘read’ the order of all of your ‘A’s, ‘T’s, ‘C’s, and ‘G’s to check for ‘mispellings’, or <variants>, in important genes such as BRCA-1 and BRCA-2. The variant is then reported back to you or your doctor. Sometimes, having a different spelling in your gene doesn’t matter much: think of the words /color/ and /colour/. Even though they are spelled differently, they mean the same thing and can both be used effectively. Similarly, you might have a variant in a BRCA-1 gene that is spelled differently, but does not cause harm. However, if color was mispelled to be kolyr, the word would be unrecognizable to many readers. If your BRCA-1 or BRCA-2 variant misspells the gene’s As, Ts, Cs, and Gs in ways the cell cannot make sense of, it might put you at higher risk of BRCA-associated cancers. A genetic test can help determine these risks based on knowledge of about your variant.
If you are concerned about your risk, a genetic test can rule out the possibility of hereditary cancer. If you have a cancer diagnosis, a genetic test can help your doctor make treatment decisions. Genetic tests ultimately help you and your doctor account for, or rule out, BRCA-1 and BRCA-2 gene defects impacting your health.
[Should I include a note about BRCA Exchange's contributions here?]
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More comprehensive resources for understanding test results can be found here