Background Disease severity is important when considering genes for inclusion on reproductive expanded carrier screening (ECS) panels. We applied a validated and previously published algorithm that classifies diseases into four severity categories (mild, moderate, severe, and profound) to 176 genes screened by ECS. Disease traits defining severity categories in the algorithm were then mapped to four severity‐related ECS panel design criteria cited by the American College of Obstetricians and Gynecologists (ACOG). Methods Eight genetic counselors (GCs) and four medical geneticists (MDs) applied the severity algorithm to subsets of 176 genes. MDs and GCs then determined by group consensus how each of these disease traits mapped to ACOG severity criteria, enabling determination of the number of ACOG severity criteria met by each gene. Results Upon consensus GC and MD application of the severity algorithm, 68 (39%) genes were classified as profound, 71 (40%) as severe, 36 (20%) as moderate, and one (1%) as mild. After mapping of disease traits to ACOG severity criteria, 170 out of 176 genes (96.6%) were found to meet at least one of the four criteria, 129 genes (73.3%) met at least two, 73 genes (41.5%) met at least three, and 17 genes (9.7%) met all four. Conclusion This study classified the severity of a large set of Mendelian genes by collaborative clinical expert application of a trait‐based algorithm. Further, it operationalized difficult to interpret ACOG severity criteria via mapping of disease traits, thereby promoting consistency of ACOG criteria interpretation.

Purpose of reviewWith the advent of precision medicine and demand for genomic testing information, we may question whether it is time to offer genetic testing to our patients with Parkinson disease (PD). This review updates the current genetic landscape of PD, describes what genetic testing may offer, provides strategies for evaluating whom to test, and provides resources for the busy clinician.Recent findingsPatients with PD and their relatives, in various settings, have expressed an interest in learning their PD genetic status; however, physicians may be hesitant to widely offer testing due to the perceived low clinical utility of PD genetic test results. The rise of clinical trials available for patients with gene-specific PD and emerging information on genotype-phenotype correlations are starting to shift this discussion about testing.SummaryBy learning more about the various genetic testing options for PD and utility of results for patients and their care, clinicians may become more comfortable with widespread PD genetic testing in the research and clinical setting.