Dear David, I should also mention that 2 years ago I did an analysis of the i SNPs at 23andMe. Below is that analysis: "453,854 atDNA SNPs in 23andMe v4 data are also found in 23andMe v2 data in a 2009 download. Of these SNPs, 419 are i SNPs. 453,357 atDNA SNPs in 23andMe v4 data that are also found in 23andMe v2 data in a fresh download. Of these SNPs, 546 are i SNPs. 509,630 atDNA SNPs in 23andMe v4 data that are also found in 23andMe v3 data in a fresh download. Of these SNPs, 6153 are i SNPs. 304,864 atDNA SNPs in 23andMe v4 data that have rs numbers are also found in Family Finder in a fresh download. I then checked the 41,855 i atDNA SNPs in 23andMe v4 data and checked for matching positions in the Family Finder data. I found that there were 2556 i atDNA SNPs in 23andMe v4 data that had matching positions in the Family Finder data." Therefore 23andMe has chosen to name at least 2556 SNPs that have rs numbers as i SNPs for whatever reason. See http://www.yourgeneticgenealogist.com/2013/12/23andme-releases-sample-of-the ir-new-v4.html for more background on my analysis. Sincerely, Tim Janzen -----Original Message----- From: genealogy-dna-bounces@rootsweb.com [mailto:genealogy-dna-bounces@rootsweb.com] On Behalf Of David Schroeder via Sent: Saturday, December 12, 2015 9:33 PM To: genealogy-dna@rootsweb.com Subject: [DNA] My Raw Data Files - Comparison 23andme vs AncestryDNA I have tested at both 23andme (V3) and AncestryDNA. I have written a program to add the raw data file information into a MySQL database, creating separate tables for my 23andme results and my AncestryDNA. I am trying to understand some things. I can understand all the A, C, G, T lettering. The single letters represent SNPs on my Y and X chromosomes. I also understand that '--' is a no call. What are 'DD' and 'II'? I also found that AncestryDNA had no 'AT' SNPs for me, but 23andme had 611: Can anyone explain why I have no 'AT' SNP pairs in my AncestryDNA raw data file? I verified this by browsing my Ancestry Raw data file. I had every other SNP pair represented. The final question is about RSIDs. What are the ones that begin with 'i' in my 23andme raw data file? I have 10,709 RSIDs that begin with 'i-----'. David