What is the difference between diagnostic yield and clinical utility?

• A. Yield is the cost; clinical utility is patient satisfaction
• B. Yield is the proportion of tests identifying a causative variant; clinical utility is how results affect management
• C. Yield is lab turnaround time; utility is number of genes tested
• D. They are the same

Answer: (B)

Diagnostic yield is about how often a genetic test finds a causative variant that explains the patient's condition. In other words, it’s the proportion of tests where a pathogenic or likely pathogenic variant is identified that accounts for the phenotype. Clinical utility, on the other hand, is about what you do with that result—whether it changes patient management, surveillance, treatment options, reproductive decisions, or overall outcomes.

So a test can have a high diagnostic yield if it frequently finds a pathogenic variant in the tested group, but its utility depends on whether those findings lead to tangible actions or benefits for the patient. Conversely, you might have a result that informs management in meaningful ways even if the overall diagnostic yield isn’t very high. Note that variants of uncertain significance don’t contribute to diagnostic yield because they don’t establish a clear cause, and diagnostic yield isn’t about cost, turnaround time, or the number of genes tested.