11 - The postgenomic era: Genetic & genomic applications for clinical practice

Abstract

Genetic research has fundamentally changed how human health and disease are viewed. PAs should seek guidance from the latest clinical practice guidelines regarding diagnosis, testing, and treatment for genetic disease. Specifically, PAs should understand that diagnoses such as breast cancer or Alzheimer disease (AD) must be thought of as phenotypic descriptions. That is, different individuals may appear clinically to have the same disease, but genetic or genomic testing may reveal that they have different genetic etiologies (genetic heterogeneity). If the treatment varies between forms of these diseases, further medical workup is necessary to characterize the type of disease. This will likely be accomplished with the assistance of genetic and genomic testing technologies. Genomic testing enables the testing or study of an entire human genome rather than just the analysis of single alleles and will likely replace most genetic testing. Direct-to-consumer (DTC) genetic testing is coming into more widespread usage; PAs will work with individuals and families who have had DTC genetic testing and want to better understand their test results and/or to have further confirmatory genetic testing. Depending on their practice setting, PAs may choose whether to screen for genetic disorders using family medical histories (FHx); recommend and/or order genetic testing or next-generation sequencing (NGS) or guard against inappropriate testing; or collaborate with genetic health care providers and/or provide continuity of care for those individuals who have had testing and were found to have a significant result.