Here are some commonly-used genetic terms:
DNA: deoxyribonucleic acid (DNA) is the material inside each of your cells that contains all the genetic information your body needs to function
Gene: a piece of DNA that instructs your body to make a certain product
Chromosome: a large piece of DNA that carries many genes
Variant: a change in the sequence of the DNA that may or may not affect the function of the gene(s) or product(s). Variants can be pathogenic, likely pathogenic, benign, or have unknown significance.
- Pathogenic: Pathogenic variants (sometimes called a mutation) are changes in your DNA that lead to a known health condition. If you have a pathogenic variant in your DNA, you will receive a positive test report.
- Likely pathogenic: Likely pathogenic variants (sometimes called a mutation) are changes in your DNA that are expected to lead to a known health condition. If you have a likely pathogenic variant in your DNA, you will receive a positive test report.
- Variant of unknown significance (VUS): A variant of unknown significance (VUS) is a change in your DNA that has an uncertain or unknown impact on your health. If you have a VUS, you do not necessarily have an increased risk of developing a certain health condition. Over time, the scientific and medical community will identify new evidence about each particular VUS and the classification of the variant may change from VUS to pathogenic, likely pathogenic, or benign. If a VUS in your sample is reclassified to pathogenic or likely pathogenic, Invitae will notify your clinician and issue an updated report.
- Benign: Benign variants are changes to the DNA that do not lead to known health conditions. DNA contains many, many variants and most are benign. Benign variants are not included in your test report and you will receive a negative test result if no other variants are identified.
Deletion or duplication: Deletions and duplications are large sections of DNA that are missing or extra. They can range in size from a small section within a gene to a large chunk containing multiple genes. Invitae’s tests include detection of deletions and duplications in most cases.
Genetic testing: the process of analyzing an individual’s DNA to look for variants in their genes that are associated with health conditions.
Genetic counseling: an appointment with a healthcare provider specifically trained in medical genetics to help individuals understand the process of genetic testing, what their genetic test results mean, and the implications for themselves and their family members.
Pedigree: a chart showing the family tree of an individual that can be used to analyze inheritance of a trait or health condition.
Proband: the first person in a family to receive genetic testing, usually the person in the family who has a health condition. A proband’s genetic test results often times has implications for their family members.
Inherited variant: a genetic variant that was passed down from a parent or ancestor.
De novo variant: a genetic variant that was not passed from a parent or ancestor, but arose new in an individual’s DNA.
Inheritance pattern: how a trait or a health condition is inherited through a family.
- Autosomal dominant: an individual with a single disease-causing (pathogenic or likely pathogenic) variant in a gene will be affected with or at risk for developing the disorder.
- Autosomal recessive: an individual with at least two disease-causing variants, one in each copy of a gene, will be affected by the disorder. Learn more >
- X-linked: X-linked inheritance means that the gene associated with the disorder is located on the X chromosome. Females have two X chromosomes, while males have one X and one Y chromosome. Since males have only one X chromosome, pathogenic or likely pathogenic variants in genes on the X chromosome typically affect males more often than females. Learn more >