The effect of a genetic variant on quantitative real-time PCR in a case of disseminated adenovirus infection

•TaqMan probe mismatch causes real-time PCR curve abnormalities.•These abnormal curves can be corrected with re-engineered, matched probe.•Abnormal curves can also be corrected by increasing mismatched probe concentration.

A patient developed disseminated adenovirus infection following bone marrow transplant. TaqMan real-time PCR showed reduced maximum fluorescence in the amplification curve from all plasma samples. Sequencing revealed three single nucleotide mismatches between the TaqMan probe and probe binding region. Real-time PCR with probe matching the isolate sequence showed normal amplification and a higher copy number result.