Preimplantation diagnosis: Used after the in vitro fertilization to diagnose a genetic disease or condition in a preimplantation embryo.

Prenatal diagnosis: Used to diagnose a genetic disease or condition in a developing fetus.

Newborn screening: Performed in newborns to detect certain genetic diseases for which early diagnosis and/or treatment are available. Screening is usually done for phenylketouria and other metabolic disorders, sickle-cell anemia and Tay Sachs disease.

Carrier screening: Performed to determine whether an individual carries one copy (allele) of a mutated gene for diseases such as cystic fibrosis, sickle-cell anemia or Tay Sachs disease, hemophilia, and Huntington’s disease.

Diagnostic/Confirmatory Testing: Used to identify or confirm the diagnosis or condition in an individual.

Predictive testing: Determines the probability that a healthy individual with or without a family history of a specific disease might develop that disease. Presymptomatic testing is predictive testing of individuals with family history. It is done for the diseases or conditions like Huntington’s disease where people with a positive test result have higher probability of developing the condition. Can also be done to estimate the risk of developing adult-onset cancers and early-onset Alzheimer's disease.

Compatibility testing: Genetic testing is also done to increase the success of organ transplantation, by determining the presence of a close match between the genetic types of an organ donor and a recipient.

Forensic and Identity Testing:Genetic testing is used to provide answers when questions of identity or criminal intent arise. These results allow criminal investigators to match DNA from evidence found at a crime scene, as well as a means to confirm the identity of an alleged parent. A list of possible specimens that contain DNA evidence is available here.