A proband variant is assigned the category HasDeNovoRefAllele if all of the following are true:
The variant has an allele that:
The coverage of the father's genotype at this variant position is at least denovo_ref_allele_min_father_coverage.
The coverage of the mother's genotype at this variant position is at least denovo_ref_allele_min_mother_coverage.
See also HasDeNovoNonRefAllele.