dbVar is NCBI's database of genomic structural variation – it contains insertions, deletions, duplications, inversions, multinucleotide substitutions, mobile element insertions, translocations, and complex chromosomal rearrangements. (from the NCBI web site)
NCBI provides an FAQ on dbVAR at http://www.ncbi.nlm.nih.gov/dbvar/content/help/
This guide will show a sample variation viewer using the LCT gene as the source.
First change the database search to dbVar and create a search for the gene we are interested in and limit to the organism:
The resulting page shows larger scale variations for this this gene. Choosing one, nsv1123397, click on the link to view this variation in more detail: