Expand knowledge – Genomics technology
Genomics technology is embedded into all areas of medicine. About 7,000 hereditary conditions exist which are individually rare, but collectively not uncommon. The original focus of human genetics research upon rare hereditary conditions has expanded greatly. Genomics is now integrated into all areas of medicine including common diseases such as cancer, heart disease and diabetes.
Technological advances in laboratory testing and computational biology have created rapid transformation, decreased cost and increased population access to genetic testing. However, challenges remain. Some of the greatest impact of genomics technology relates to cancer, where precision medicine customises risk assessment, diagnosis, prognosis, and treatment to the individual.
In the following, our focus is on actionable genetic tests, which have evidence-based medical value in disease prevention, diagnosis, risk stratification and treatment. Genetic tests differ from other medical tests as they are always optional.
Complexity – Rapid growth in genetic test numbers
The large degree of utilisation of genetic testing in the U. S. is illustrated by Concert Genetics’ payor data:
“Genetic testing is the linchpin of precision medicine, but the rapid pace of change in the market makes it enormously complex. Today, there are more than 140,000 unique genetic testing products on the market, and an average of 10 to 15 new products are added each day…”1,2
- The increasing demand for genetic testing is driven by healthcare providers and the public.
- The pattern of access to healthcare has changed. Today, the individual is the central focus of their own care, proactively investigating healthcare options including genetic testing. Healthcare providers partner with their patients to make informed, collaborative (shared) decisions, rather than directing decision-making, as in the past.3
- The public’s desire for independent decision-making has influenced growth of the direct-to-consumer (DTC) industry in genetic testing.
- Genetic testing, previously performed only for medical indication, can now be obtained for the individual’s personal interest (such as perceived health benefits).
- Perceived benefits of genetic testing (including whole genome sequencing/whole exome sequencing – WGS/WES) for the unselected population must be balanced with evidence of actionable benefit and risk.
- Polygenic risk scores currently have limited clinical utility.
The following data limitations in identifying genetic testing prevalence have been found:
- Challenges include, but are not limited to diverse data sources, data collation issues, and many payors (commercial, public, self‑pay).
- Research-based testing: data (including WGS/WES) is difficult to obtain. Some of these research-based test results are actionable and are communicated to the patient.
- DTC test data is difficult to obtain.
Uncertainty – What does the genetic test result mean?
The following relates to rare single gene hereditary conditions. Genetic tests for actionable findings seek “pathogenic variants” (previously called “mutations”). Genetic variants are classified along a spectrum, based upon specific laboratory parameters with evolving interpretation (see Figure 1). This broad spectrum of variation in interpretation is unusual in clinical medicine.
Figure 1: Searching for pathogenic variants