Shared segments: How my 3 siblings compare to me

In addition to my own test, I now have 3 of my siblings who have taken autosomal DNA tests.   I've been concentrating on our paternal line because it contains a research roadblock beyond the 2nd great Grandfather of our Cook(e) line.  I was curious what Paternal DNA I had gotten from Dad that none of my other siblings had.  A little background---We are full siblings.  Dad passed before we began DNA testing.  Our Mom has tested.  I've generated phased kits for myself and my 3 siblings at GEDmatch.

I compared each of my 3 sibling's Paternal Phased kits to my Paternal Phased kit and I painted those segments on my profile at DNApainter.  You can click on this to enlarge.  I didn't include Chr 23(X) in the comparison.  As you can see in the image below there are portions on pretty much each of the chromosomes where none of the 3 match with me. (Note:  You should exclude the first portions of Chr 13, 14, 15, 21, and 22 which aren't included in testing.)

Looking at these paternal segments of each of the siblings compared to me, there is a range of about 200 cM.  My sister and I seem to have gotten a variety of different segments from our Dad. See the comparison of the paternal matching segments for she and I in the image below.

Paternal Overlap with Siblings --Dad (Non-Tested Parent)
Becca to Marie  1499.9 cM shared  42 segments
Michael to Marie  1662.4 cM shared 45 segments
David to Marie 1712.4 cM shared 48 segments

I used the same process explained above to compare the maternal segments.

With very few exceptions it looks like my siblings and I have received more of the same maternal segments.  That would make me think that more of the DNA which Mom had might have been lost.  Thankfully she tested so I have her test for comparison to others.

My sister also shares the least amount in common segments maternally as well.  Still a good bit more In-Common-With segments on the maternal lines than paternal.  My recommendation remains the same.  Test as many siblings as possible.

Maternal Overlap with Siblings--Mom(Tested Parent)
Becca to Marie 2473.8 cM shared  63 segments
Michael to Marie   2605.2 cM shared 56 segments
David to Marie 2696.5 cM shared 63 segments

Working AncestryDNA circles and a few observations

My sister and I have both tested at AncestryDNA.  When I am working on a segment and it is pointing in the direction of a specific ancestor, I always check my AncestryDNA circles to see if I have a Circle for that particular ancestor or ancestor couple.  I work the circles.  What do I mean by work?  I have a spreadsheet template I use.  I begin by adding the Ancestor's name at the top.  The spreadsheet has columns for:

• Ancestry User Name
• Match or Match to Circle
• Estimated cMs/segments
• Group(Child thru which they descend)
• GEDmatch #(known and added as they upload)

I add the info for each circle I work and this helps me to track not only who matches me but the descendant pathways.  Also and probably the most important thing for me is that I can see at a glance which tester would be the most valuable to have their info at GEDmatch.   I generally write those who Ancestry estimates match me on multiple segments or at amounts greater than 15 cMs.  I ask them to consider uploading to GEDmatch if they are not already there and if they have uploaded, how to identify them among my many matches.  I want to focus on these larger matches for a number of reasons. The circle membership gives me a pretty good idea of where they could match me. It is easy to get overwhelmed by all the matches but I feel if you focus on the larger ones, those will help in identifying others.   I also like to look at the smaller matches and see how their estimated segment matches are in comparison with my sister's results.  If they match her at amounts over 15cMs I also message them. 

Stay focused on the larger matches when trying to get folks to GEDmatch.  However do not forget the randomness of DNA.  Siblings can vary greatly in what matches they have.

My sister and I are a great example of that.

Since Mom tested I was able to make phased kits(thanks to GEDmatch tools) which show the matches that each of us got from Dad(who passed before we began DNA testing.)  I have compared my Paternal Phased Kit to my sister, Becca's Paternal Phased Kit and also compared each of our Maternal Phased Kits.   Below are the results

Comparing Paternal Phased for Marie and Paternal Phased for Becca(Full siblings)

(Chr 1-22, X not included)

Largest segment = 134.6 cM

Total of segments > 7 cM = 1,526.2 cM

33 matching segments

Estimated number of generations to MRCA = 1.6

Comparing Maternal Phased for Marie and Maternal Phased for Becca(Full siblings)

(Chr 1-22, X not included)

Largest segment = 145.6 cM

Total of segments > 7 cM = 2,513.8 cM

50 matching segments

Estimated number of generations to MRCA = 1.3

So you can see that on our Paternal lines we appear to have gotten a greater variety, while Mom seems to have given us more of the same.  

Table below shows another example of the randomness. The amounts shown are those estimated by Ancestry and they tend to be slightly higher at GEDmatch.

Comparing segment matches we have to
members of a Paternal Ancestor Circle.  

Working on Identifying larger segment matches

I have been mapping my DNA segments to specific contributing ancestors for a little over 2 years now.  It is something I really enjoy doing but at the same time, it can be very frustrating.  When I first began I was the only one in my family who had tested.  A few months after getting my results I bought a test for my Mom who agreed to test.  This really helped when her results were in and uploaded with mine to GEDmatch as I was able to differentiate between matches which were on her side and those which were on my paternal side of the family.  GEDmatch has a tool that is extremely useful if you only have one parent who is able to test.  It allows you to use that parent's DNA to subtract the DNA they gave you leaving you with a Phased kit which containing just the DNA that the un-tested parent contributed.  Last year my sister tested and her results came in which gave me more date with which to work.  I couldn't have asked for better results.  While she is a full sister she and I match at 2513.7 cMs(not including the X amount) which is on the low end of full siblings meaning we received varying DNA from our parents.  I also created a phased kit of the DNA which she received from Dad and compared it to the phase kit of the DNA which I received.  It has given me a pretty good visual phasing though it's not perfect you can see the re-combinations.  I used this comparison to mark the segments where we were opposite and was able to narrow down some segments to PGM or PGF.

When I first got my results I was busily collecting my matches.  I collected anything 5cMs and up.  I guess I thought I'd miss something if I didn't.  Sure, I could have, but now I am working with the larger segments and I wish I had done this when I began.   I use GenomeMate Pro to catalog my matches and keep track of the kits I manage.  Most of the time I have anything under 12 cM hidden when viewing the matches on each chromosome.   I thought it would be a good project to tackle some of the larger segments.   I wanted an easy way to see the larger matches across all of the chromosomes at the same time. Below is what I did using my paternal phased kit

• Run a Matching Segment report set where it only includes 20+ cM segments
• Paste the results into a spreadsheet
• Format with headers to your preference 
• Set the sorts so it will sort by Chromosome and then by starting point
• Use the fill cell tool to group the ones which cover the same area
• Add a column on the far right of your Spreadsheet.  This column will be used to identify whether the match or the match group is from the Paternal Grandfather or the Paternal Grandmother's lines.

 How my chromosome, starting and ending position and segment size groups look
minus any identifying info(GEDmatch #s email addresses cropped out of pic)

I did the same thing using the paternal phased for my sister.  Yesterday I printed the spreadsheets and put them in  sheet protectors in a binder.  Today I begin reviewing our largest unassigned segments.   Technology is great, but I really do better if I have a printed paper to look at while searching over a pedigree chart rather than flipping back and forth from the chart to an actual spreadsheet or program.  Just the way I'm wired I guess.  I'd love to hear what has worked for others 

This is how I have my outer column for now  I could do a reprint later as I identify
PGM or PGF lines....but for now I will edit the old fashion way
(remove from sheet protector use color pencil and pen to add info
replace in sheet protector)

DNA Logic Puzzles

My Dad always loved the Logic puzzles in the Dell Puzzles Magazines. As I'm working on DNA matches today I can't help thinking about him.  Not just because I am working on my paternal matches but that he would like the logic I am using.  While I have had my DNA results and those of my Mom for over a year, my sister's results came in not long ago and we now have her kit at GEDmatch. She is a full sibling but there seems to be a good variation in the people which we match due to the randomness in the 50% which you get from each of your parents..  What does that mean for me? I can take her kit....run it with Mom's to phase out Mom's matches and create a kit of Sis' DNA she got from Dad...which I can then compare to my DNA which I got from Dad.  If I know that one of us matches Dad's Mom along one segment..and it's a segment that we don't match along....I then know that the other one of us matches Dad's Dad along that segment which we don't have in common.  After all...Dad only had two to offer...so you got one or the other.

An Example:
Chromosome 4 on my Paternal side(which I can see by using the phased kit) I have a section from about 4-40 which I know I can attribute to my Paternal Grandmother's  Morrow/Sutton lines. My Sister has NONE of these same matches along that same segment of her Paternal side(I can again distinguish her Paternal from her Maternal matches by using the phased kit of her DNA she got from Dad mentioned earlier).  By this I can conclude that the matches along that segment for her are from my Paternal Grandfather's side and somewhere back along the Cook/Putman or King/Manire lines.


While this won't solve all of my unknowns, it is a big help in knowing where to look for the connection for these matches. So many times I wish that the matches had some idea of which side I match them along.This is one of the greatest things about having a parent and a full sibling that have also tested.