Which Myriad test is used to determine HRD status?

• A. MyChoice CDx
• B. HRD Panel
• C. OncoVantage
• D. BRACAnalysis

Answer: (A)

Homologous recombination deficiency (HRD) is a tumor feature that indicates impaired DNA repair via the HR pathway and helps predict response to PARP inhibitors. To determine HRD status, a test must assess genome-wide instability in addition to any BRCA mutation status. MyChoice CDx is designed for this purpose: it provides BRCA1/2 mutation status and a composite HRD score derived from genomic instability markers, such as loss of heterozygosity, telomeric imbalance, and large-scale state transitions. A high HRD score classifies the tumor as HRD-positive, guiding the use of PARP inhibitor therapy. Other options either focus solely on germline BRCA testing or are not the standard Myriad assay used to determine HRD status.