Go Back   Family Tree DNA Forums > Universal Lineage Testing (Autosomal DNA) > Family Finder Advanced Topics

Family Finder Advanced Topics Advanced discussion about Family Tree DNA's Family Finder Product.

Reply
 
Thread Tools Display Modes
  #1  
Old 30th July 2017, 12:04 PM
kjsargent kjsargent is offline
FTDNA Customer
 
Join Date: Mar 2014
Posts: 5
Exclamation 24,323 No-calls is too much (3.5%)

I was working with small segments when I noticed that my fathers kit has 24,323 No-calls (3.5%) percent. I no longer trust the results I am getting. Is there an FTDNA policy that might retest the existing sample, or allow me to send in another sample?

My mother's test also seems high, especially compared to AncestryDNA and 23andme.
Her test has No-calls = 16462 = 2.3172827740952 percent.

Last edited by kjsargent; 30th July 2017 at 12:11 PM. Reason: Adding more information
Reply With Quote
  #2  
Old 30th July 2017, 12:42 PM
John McCoy John McCoy is offline
FTDNA Customer
 
Join Date: Nov 2013
Posts: 526
Those numbers sound high, but I have to wonder how much difference they would make in finding matches out to about 4th cousins. The matching algorithms, as I understand them, treat "no calls" as if they matched, and allow some low level of mismatching as well. I have a feeling the effect will be very small, and possibly not even detectable. If you do get retested, you would be in a perfect position to measure the effect, by comparing your match lists for the "bad" and "good" samples. It's important to have some real data for these situations, so please let us know what happens.
Reply With Quote
  #3  
Old 30th July 2017, 03:54 PM
kjsargent kjsargent is offline
FTDNA Customer
 
Join Date: Mar 2014
Posts: 5
Not too long ago, I decided to submit both my parents DNA to FTDNA for mtDNA full. I manage kits on 23andme for both my parents, wife, son, fathers 2 sisters and various aunts/uncles on my mother's side. I already have my yDNA-111. All these kits were transferred to FTDNA.

I decide to add Family Finder to both parents believing that it would be more accurate when compared to other FTDNA tested subscribers. I sort of justified thinking it would save me time at some point.

Now, I'm not so sure. The main effect of no-calls is to predict a relative to be closer than if the no-call had not happened.

When I compare the 23andme/FTDNA transfer kit with the FTDNA kit, I have 1 more 3rd cousin, 8 more 4th cousin, and about 90 more distant cousins. I also concerned the segments, which are clues to where on my tree we are related, may send me down a rabbit hole.

I will try to contact the 3rd cousin in question to see which kit is more accurate.

Below is from www.gedmatch.com with some interesting statistics.

AncestryDNA:
Number of regular SNPs = 680,968
Heterozygosity index = 0.148916 (fraction of total SNPs that are heterozygous)
No-calls = 10593 = 1.5317520797153 percent.

23andme:
Number of regular SNPs = 943,313
Heterozygosity index = 0.206257 (fraction of total SNPs that are heterozygous)
No-calls = 4552 = 0.47338705735658 percent.

FTDNA:
Number of regular SNPs = 686,078
Heterozygosity index = 0.277065 (fraction of total SNPs that are heterozygous)
No-calls = 24,323 = 3.4238409011249 percent.
Reply With Quote
  #4  
Old 31st July 2017, 03:58 PM
ltd-jean-pull ltd-jean-pull is offline
FTDNA Customer
 
Join Date: Jun 2016
Posts: 373
I hadn't noticed this function at Gedmatch.

The numbers for the kits I manage range from:
Number of regular SNPs = 695658
Heterozygosity index = 0.293488 (fraction of total SNPs that are heterozygous)
No-calls = 2167 = 0.31053630924659 percent.

To
Number of regular SNPs = 691207
Heterozygosity index = 0.278875 (fraction of total SNPs that are heterozygous)
No-calls = 19194 = 2.7018543048222 percent.


The top kit belongs to an enthusiastic tester who leapt out of bed and did the swab before breakfast the day after it arrived and would have followed the instructions exactly.

The bottom kit was a reluctant tester who didn't appear to swab very vigorously and I was concerned we might need to send another kit.
Reply With Quote
Reply

Bookmarks


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
No calls lolkha BIG Y and SNP Discovery 0 22nd January 2016 01:39 AM
No Calls 1798 Family Finder Advanced Topics 53 13th January 2015 01:33 PM
Checking for No-Calls jbarry6899 BIG Y and SNP Discovery 2 1st November 2014 05:45 PM
mtDNA calls wkauffman BIG Y and SNP Discovery 3 27th March 2014 01:50 PM
No calls with MtDNA FGS thetick DNA and Genealogy for Beginners 5 8th August 2011 07:19 PM


All times are GMT -5. The time now is 06:00 PM.


Family Tree DNA - World Headquarters

1445 North Loop West, Suite 820
Houston, Texas 77008, USA

Phone: (713) 868-1438 | Fax: (832) 201-7147
Copyright 2001-2010 Genealogy by Genetics, Ltd.
Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.