Description

This track contains information about single nucleotide polymorphisms and small insertions and deletions (indels) — collectively Simple Nucleotide Polymorphisms — from dbSNP build 147, available from ftp.ncbi.nih.gov/snp. A subset of the items in this track are contained in Mult. SNPs(147), which are SNPs that have been mapped to multiple locations in the reference genome assembly.

The default maximum weight for this track is 1, so unless the setting is changed in the track controls, SNPs that map to multiple genomic locations will be omitted from display. When a SNP's flanking sequences map to multiple locations in the reference genome, it calls into question whether there is true variation at those sites, or whether the sequences at those sites are merely highly similar but not identical.