Abstract: A genomic data analyzer may process the next generation sequencing data of a patient sample to identify whether a variant is present (positive variant calling), absent at a high confidence (negative variant calling), or equivocal (possible false negative calling) as falling under a calculated limit of detection (LOD). This LOD estimate corresponds the lowest variant allele fraction (VAF) detectable at the required sensitivity (true positive rate). The presently disclosed genomic data analyzer may improve any legacy variant caller by automatically calculating the limitations of variant calling detection for a user-defined sensitivity and minimal VAF of interest for any variant genomic position and/or mutation, depending on analytical factors of the NGS assay and workflow such as the sample type, the DNA sample amount and the NGS assay library conversion rate (LCR), and/or its molecular barcoding capability, as well as its NGS assay error profile.