When the Human Genome Project was completed twenty years ago, it marked the beginning of an exciting new era in life sciences. It provided us with the blueprint of human life and elevated our understanding of biology to a new level. In less than 20 years, genetic testing has become a significant part of our lives.

The genetic testing that is available to us today can be divided into two main categories, non-clinical and clinical. Non-clinical genetic testing has evolved to include testing for a wide array of characteristics and traits, from ancestry to how we metabolize nutrients, alcohol, caffeine, as well as other biological, physical, sensory, and reproductively relevant traits.

Genetic testing is categorized as clinical if the results will be used for medical diagnosis, disease prevention, treatment, or management decision-making. Clinical testing must be performed in labs with a Clinical Laboratory Improvements Amendment (CLIA) certification to safeguard against testing issues due to sample handling or data reporting errors.

Ancestry tracing has grown in popularity with the emergence of multiple companies like 23andMe, My Family Tree, and African Ancestry. There are different types of ancestry testing available including biogeographical, maternal, and paternal ancestry testing. Biogeographical ancestry analyzes chromosomes inherited from both parents and commonly provides estimates of African, European, and Asian ancestry. Several companies are capable of providing population level information tracing an individual back to specific ethnic or tribal groups.

Our genetic heritage from our mother’s (maternal) and father’s (paternal) family lines can be explored individually. Maternal ancestry testing analyzes the genetic material found in mitochondria, the tiny power plants in your cells, called mitochondrial DNA or mtDNA. It is different from the chromosomal DNA you inherit from both parents because it is only inherited from your mother. This makes it ideal for tracing maternal ancestry. Populations of the world can be compared and grouped using their mtDNA sequence. All mtDNA can be traced back to the most recent common ancestor of modern humans referred to as “Mitochondrial Eve”. Paternal ancestry testing analyzes Y chromosome variants which are unique to genetic males and inherited exclusively from their fathers.

Genetic testing for biomarkers, biometrics, characteristics and traits is also available to consumers. Nutrigenomics, the genetics of nutrient metabolism, is an area of widespread interest for health and wellness enthusiasts. In addition to nutrition, there are companies that offer testing on other health related traits including athletic performance, fertility, skin care, and the genetics of drug metabolism or pharmacogenomics.

MedAnswers offers the Fertility Wellness Genetic Test that provides information on nutrigenetic factors and traits relevant to fertility including cholesterol, insulin resistance, and genetic weight. In addition, information on variants associated with polycystic ovary syndrome (PCOS) is provided. This information is intended for educational or research purposes only and is not for clinical use.

Clinical genetic testing is conducted throughout all stages of life and is focused on human disease and reproduction. Prior to having children, couples from high-risk populations may use a form of genetic testing called carrier screening to test for the presence of known disease-causing variants for conditions like cystic fibrosis, fragile-x syndrome, and Tay-Sachs disease.

If a couple uses some form of assisted reproductive technology (ART) like in vitro fertilization (IVF), the embryo is screened for genetic abnormalities using one of multiple forms of preimplantation genetic diagnosis (PGD). This testing is conducted to maximize the likelihood of having a successful pregnancy and a healthy child. It tests for disease like cystic fibrosis and structural changes in a parent’s chromosomes. This is commonly an option for couples with a family history of a condition that they want to reduce the risk of or to ensure that a child will have a matching bone marrow/stem cell donor.

After a woman conceives, her doctor will recommend prenatal genetic screening for conditions like Down syndrome as well as other chromosomal disorders. This testing is conducted to identify issues that may require specialized medical care to give parents the time to prepare or make other decisions regarding the pregnancy.

When a child is born, newborn genetic screening for congenital and metabolic disorders for which early diagnosis is critical, like sickle-cell disease and phenylketonuria (PKU), are prescribed. Each state has a list of conditions and disorders screened, the severity of which may be significantly reduced or even prevented with early intervention.

In the unfortunate event of pregnancy loss, genetic testing may be ordered in order to help identify the issue that impeded the survival of the child. The results of this testing can inform future attempts to have children

Throughout the remainder of the life cycle, genetic testing can be used as a diagnostic to confirm clinical findings of a disease that may have genetic causes, predictively in pre-symptomatic individuals with a family history for a genetic disease, and to help determine which medication and dosage will be most effective and beneficial for you.

Research on rare and familial diseases continues to identify causal genetic variants. As larger studies with more comprehensive sets of clinical and sequencing data are completed, the genetics of common chronic diseases will also be better understood.