Can anyone explain why a few of my SNP's come out with a single minus sign as opposed to the standard -/-, -/+ or +/+? Is a single minus something to be aware of? Also, do you guys ignore the -/- because it means nothing is wrong or can that also be a good sign and those should be investigated as well? Finally, what about large chunks of blanks for SNP's its like big pieces of missing data. What's that about?