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  #1  
Old 21st June 2017, 07:43 AM
T E Peterman T E Peterman is offline
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No calls in Autosomal data??

What is the likelihood of a few random "no calls" in autosomal data interfering with Family Finder match reporting.

I have a handful of matches that are not shared with my father. However, the matches in question are shared by his siblings & share the identical segment as me. Most of these are in the speculative range (7 to 10 centimorgans).

My assumption is that my father is being by-passed in the matching because of no calls.

Timothy Peterman
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  #2  
Old 21st June 2017, 10:25 AM
georgian1950 georgian1950 is offline
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T E, has your mother been tested?
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  #3  
Old 21st June 2017, 10:34 AM
Ann Turner Ann Turner is offline
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Quote:
Originally Posted by T E Peterman View Post
What is the likelihood of a few random "no calls" in autosomal data interfering with Family Finder match reporting.

I have a handful of matches that are not shared with my father. However, the matches in question are shared by his siblings & share the identical segment as me. Most of these are in the speculative range (7 to 10 centimorgans).

My assumption is that my father is being by-passed in the matching because of no calls.

Timothy Peterman
No calls don't affect segment matching. However, it may be that your father doesn't have enough small (meaningless) segments to reach the 20 cM total threshold required if the longest segment is less than 9 cM.
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  #4  
Old 21st June 2017, 10:59 AM
prairielad prairielad is offline
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Quote:
Originally Posted by Ann Turner View Post
No calls don't affect segment matching. However, it may be that your father doesn't have enough small (meaningless) segments to reach the 20 cM total threshold required if the longest segment is less than 9 cM.
As Ann says, it is most likely due to father not meeting the matching thresholds if segment is under 9cM.

This is where Gedmatch comes in handy if both you and match utilize site. You would probably see the segment in your father as Gedmatch allows one to lower thresholds if needed, by default they show all segments of 7cM or greater
Where as FTDNA will only show you matches who share 20cM or greater in total DNA, failing to meet that, they will also show matches under 20cM in total DNA if longest segment is over 9cM.
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  #5  
Old 21st June 2017, 11:04 AM
T E Peterman T E Peterman is offline
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My mother passed away in 1999. I am the admin of a large autosomal project (over 80 participants). Close relatives include: myself, my father, paternal uncle Melvin, paternal uncle Paul, maternal uncle Roy E., maternal aunt Martha. Beyond this, participants include a number of first cousins & second cousins to my father, as well as first cousins & second cousins to my mother.

Is it possible for my paternal uncles & I to share segments with a match, but for my father to not share the same segment with the match? I don't see how this would be possible. My inclination is to mark these as IBS in Genome Mate Pro.

I'm talking about maybe 50 matches out of 2,000 or more, so this isn't a huge problem.

Timothy Peterman
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  #6  
Old 21st June 2017, 11:11 AM
T E Peterman T E Peterman is offline
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Most of these segments are under 9 cms. I could see a case where an uncle may have shared 21 cms total & my father shared 19 cms, with the different being a small segment elsewhere. I could have inherited a similar small segment from my mother that isn't shared with any paternal relatives, but which nonetheless places me back over 20 cms.

The last time I downloaded data into Genome Mate Pro was about May 18, 2016. That gave me 73,000+ combined matches. I just finished working my way through them & began to process some of these anomalies. This handful of matches was significant enough to get me to pose this question.

Timothy Peterman
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  #7  
Old 21st June 2017, 11:14 AM
T E Peterman T E Peterman is offline
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My father & I share 3,384 centimorgans. It sounds like I should go ahead & consider these unshared segments as belonging to paternal relatives.

Timothy Peterman
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  #8  
Old 21st June 2017, 12:25 PM
MoberlyDrake MoberlyDrake is offline
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I have quite a few matches that my mother doesn't have. Some of them I share with her 1st cousin. My father tested. He was Italian and has very few matches. I can easily tell from the matches I have in common with the matches my mother doesn't have that they are on her side.
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  #9  
Old 22nd June 2017, 07:03 AM
T E Peterman T E Peterman is offline
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As I continue to study this, I'm finding that in all or most cases, I share more centimorgans with the match than the match shares with my paternal relative. This tells me that in these cases, I am related on both paternal & maternal sides, with the shared segment coming from the paternal side.

Timothy Peterman
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  #10  
Old 22nd June 2017, 08:29 AM
Ann Turner Ann Turner is offline
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Quote:
Originally Posted by T E Peterman View Post
As I continue to study this, I'm finding that in all or most cases, I share more centimorgans with the match than the match shares with my paternal relative. This tells me that in these cases, I am related on both paternal & maternal sides, with the shared segment coming from the paternal side.

Timothy Peterman
Are you looking at total cM for this analysis? The small segments < 5 cM should be ignored.
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