Carrier screening tests have been available for clinicians to order for many years. Current guidelines rely on a patient’s self-reported ethnicity, which conflates genetic and cultural factors. Common questions being asked about the future of carrier screening are: How many genes and what genes should be on Expanded Carrier Screening panels? Should we only be testing for severe/prevalent autosomal recessive disorders? Should carrier screening evolve to a healthy patient screen including pre-symptomatic gene results? How do we make complex, clinically relevant testing more accessible and digestible to the average patient? Guidelines/recommendations for expanded carrier screening relevant to residual risk estimates will be reviewed. The ambiguity, misalignment, incompleteness, deficiency, inequity, and inconsistency of current guidelines will be explored by combining a novel genetic-ancestry analysis method and several retrospective analyses on hundreds of thousands of patients tested with expanded carrier screening. Analytical detection rates of different sequencing technologies will be compared and contrasted. Calculation of residual risk estimates will be explained, and the current shortcomings will be reviewed. A path forward for guidelines that avoid current shortcomings will be elucidated.
The Limitations and Consequences of Ethnicity-specific Guidelines for Carrier Screening
Dale Muzzey, PhD, Myriad Women's Health, Inc., San Francisco, CA, USA
Current Complexities and Future Directions of Expanded Carrier Screening
Nicole Faulkner, PhD, FACMGG, Invitae Corporation, San Francsico, CA, USA
Technological Advances and Detections Rates: Demystifying the Influence of Ethnicity on Carrier Detection and Residual Risk
Lisa Edelmann, PhD, Sema4, New York, NY, USA
Objectives:
- Describe the original intent of carrier screening and current challenges for the laboratory.
- Understand how to calculate residual risk after a negative carrier screening result.
- Explain how self-reported ethnicity is an imperfect proxy for carrier risk that measurably impairs discovery of carriers if screening is based on current guidelines.
Duration: 1.50 hr
Recording Date: November 8, 2019
CME/CMLE credit: Not available
