G-SNPM mapping strategy. G-SNPM exploits a three-stage pipeline to update the chromosomal position of a SNP. In the first stage, SOAP3-dp is used to unambiguously map a SNP against a reference sequence. Unmapped or ambiguously mapped SNPs are remapped at the second stage by exploiting SHRiMP2. At the third stage, mapped SNP sequences are analyzed to identify the SNP chromosomal position.