A method for compressing nucleic acid sequence data wherein each sequence read is associated with a molecular tag sequence, wherein a portion of the sequence reads alignments correspond to sequence reads mapped to a targeted fusion reference sequence includes determining a consensus sequence read for each family of sequence reads based on flow space signal measurements corresponding to the family of sequence reads, determining a consensus sequence alignment for each family of sequence reads, wherein a portion of the consensus sequence alignments correspond to the consensus sequence reads aligned with the targeted fusion reference sequence, generating a compressed data structure comprising consensus compressed data, the consensus compressed data including the consensus sequence read and the consensus sequence alignment for each family, and detecting a fusion using the consensus sequence reads and the consensus sequence alignments from the compressed data structure.