What kinds of direct-to-consumer genetic tests are available?

Some direct-to-consumer genetic tests, such as paternity tests, are very specific, while other tests provide a broad range of information about disease risk, ancestry, and lifestyle. No single genetic test can detect all genetic conditions, and direct-to-consumer genetic test results typically need to be confirmed by clinical genetic testing or provider-driven genetic testing.

Types of direct-to-consumer tests:

• Carrier tests
• Disease risk tests
• Pharmacogenomic tests
• Trait tests
• Lifestyle tests
• Ancestry tests
• Kinship tests

Carrier tests can determine whether someone is a carrier for a group of genetic conditions, including cystic fibrosis and sickle cell disease. A carrier is someone who has a gene variant (also called a mutation) in copy of a gene that, when present in both copies of the gene, causes a genetic disorder.

Disease risk tests can estimate a person's risk of developing several common diseases that are caused by a combination of genetic and environmental factors. These common diseases include such as celiac disease, Alzheimer's disease, and several types of cancer.

Phmarcogenomic tests provide information about how genetic variations could affect a person's response to certain medications.

Trait tests can estimate the genetic probability of having specific physical traits, such as a certain eye color, a certain hair texture, cheek dimples, or a specific type of earwax.

Lifestyle tests use genetic variations to provide information about certain topics, such as nutrition (also known as nutrigenomics), fitness, weight management, metabolism, or sleep. The company may recommend or sell specific diet or fitness programs, dietary supplements, or other products and services on the basis of your results.

Ancestry tests provide clues about the region or country where a person's ancestors might have lived, their ethnicity, and the genetic connections between families.

Kinship tests can indicate whether tested individuals are biologically related to one another. For example, kinship tests can establish whether one person is the biological father of another (paternity tests).

Direct-to-consumer genetic testing method

Most direct-to-consumer tests involve looking at patterns of common variations in the DNA called single nucleotide polymorphisms (SNPs) that may be associated with certain traits or conditions. By analyzing these SNPs, the genetic testing companies determine if a person is likely to have a high risk or a low risk for that specific trait or condition.

In some cases, direct-to-consumer genetic testing companies will sequence entire genes or all of a person’s DNA (known as a whole genome). When receiving this type of testing, it is important to remember that not all DNA variants affect a person’s health, and the health impacts of some variants may be unclear.

Before undergoing direct-to-consumer genetic testing, it is important to understand how the test is done and what the test can and cannot tell you. Consumers should reach out to the company with any questions before ordering a test kit or submitting a sample.