Challenges in providing residual risks in carrier testing.

Area of Science:

• Genetics
• Reproductive Health
• Medical Diagnostics

Background:

• Carrier screening identifies individuals who carry genetic mutations for recessive disorders.
• Residual risk accounts for carriers missed by genetic testing.
• Accurate residual risk calculation is challenged by population-specific carrier frequencies and evolving variant data.

Purpose of the Study:

• To evaluate the necessity and feasibility of precise residual risk calculations in contemporary carrier screening.
• To inform counseling practices regarding the interpretation of carrier screening results.

Main Methods:

• Review of methodologies for calculating residual risk in carrier screening.
• Analysis of factors affecting the accuracy of carrier frequency estimates across diverse populations.
• Assessment of the clinical utility and impact of residual risk on patient management.

Main Results:

• Estimates for recessive disorder incidence and carrier frequencies vary significantly across populations and are often unavailable.
• Pathogenic variant detection and frequency data change over time, requiring continuous updates to residual risk.
• Residual risks from current carrier screening are generally low, often below the risk associated with invasive prenatal diagnosis.

Conclusions:

• Precise residual risk calculations are often impractical and unnecessary due to data limitations and evolving genetic knowledge.
• Counseling should emphasize that while carrier screening may miss some carriers, residual risks are typically low.
• Focusing on precise residual risk quantification may be less beneficial than understanding the overall low residual risk in the context of reproductive decision-making.