Improving Screening for C3-associated Diseases Through Higher-Tier Testing: Strategies, Timeliness, and Programs Experiences

Newborn screening (NBS) programs face persistent challenges when screening for the diseases associated with elevated C3 (propionylcarnitine). As a biomarker, C3 is known for its limited specificity and its inability to reliably distinguish severe disease, even when urgent cutoffs are applied. These limitations make higher-tier testing essential for improving accuracy. However, programs must work to balance improved screening performance with the clinically time-critical nature of these diseases.

This webinar provided a broad, practical look at how NBS programs can successfully implement and sustain higher-tier testing for C3-associated diseases. The session began with an overview of the scientific content behind C3 and why its poor performance as a screening biomarker necessitates additional testing. Speakers then explored strategies to meet timeliness recommendations, including considerations around performing higher-tiered testing in-house versus outsourcing. 

The session is designed for NBS laboratory staff, follow-up teams, clinicians, and other NBS stakeholders seeking actionable strategies to enhance screening for C3-associated diseases.