The breakdown of amyloid (A), tau (T) positive or negative status for biomarkers and molecular PET scans, along with median and interquartile ranges (IQRs) for each biomarker are provided in Table 1. Of note, there were 6 total participants that were amyloid positive but tau negative on CSF, consistent with our experience with this commercial biomarker assay in young-onset Alzheimer’s disease variants.45 Here, MAPT is linked to early-onset autosomal dominant Alzheimer disease.