Closed:hisat2-build --snp build personal index but mapping result doesn't change

Question

[liying]

I used this command to build hisat2 index : hisat2-build -p 16 ~/hg19/chr19.fa --snp snps.txt genome ; the snps.txt only has 300 SNPs ; I used this index and hisat2 index built without snps to map, but the results (bam file) are the same... But when I used this individual's all SNPs (about 370w) to build index, the result is different... I don't know if it is caused by too few SNPs to build... Could someone give me some advice?