Fig. 1.

Allele Drop-Out related artifacts in variant identification. a One mutated (C > T, in green) and one wild type allele are shown. Only amplicons originated from primers pairing a non mutated region (in red) are randomly generated by both alleles, while primers pairing the mutated region (in blue) preferentially amplify the wild type allele. b In this configuration, a second mutation (G > A, in purple) is also present on the mutated allele. This mutation is masked by ADO effects, since the mutated allele is never amplified by blue primers. c Primer trimming (i.e., the removal of primer sequences from reads) restores the balance of aligned bases in the mutated position. d Primer trimming in this context is not sufficient to restore a balanced number of reads in the position relative to the second mutation. In order to do this, one possible approach is the removal of blue reads, generated by the amplicon affected by ADO-artifacts