Questions tagged [dna]

For questions about using DNA to further knowledge of family history, relationships, ethnic origin, and overall ancestry. Most common tests include Y-DNA, mitochondrial DNA, and autosomal DNA.

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3
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1answer
57 views

Are there different amounts of “fuzziness” in the endpoints when doing pairwise 1-1 comparisons among three people at GEDmatch?

I was performing a triangulation at GEDmatch and obtained the following start and end points for the triangulated segment on Chromosome 1 for each comparison: Person A with Person B: 19,899,991 ...
0
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1answer
176 views

Centimorgans shared with a great unclie

I have a 1400+ centimorgan Match to a great uncle on my father's side. Is it common to have this strong of a match to a great uncle? I have read this high number is usually shared with half-siblings,...
0
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1answer
738 views

Half Uncle Mystery

I discovered a match on ancestry.com that was a first cousin match to me on my fathers side but assumed it was his half sibling (we suspected existed.) We share 756 centimorgans. He is five years ...
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1answer
100 views

Is Whole Genome Testing in any way useful for Genealogy?

There are several DNA testing companies out there that are excellent for genealogists. These include Ancestry DNA, Family Tree DNA, MyHeritage DNA and 23andMe. These companies provide match lists of ...
5
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1answer
137 views

Phased psuedo-kit on GEDmatch — what accounts for huge drops in SNP count?

I guess first I should make sure I understand how GEDmatch stores raw data -- I'd guess that during "tokenization", GEDmatch turns my raw data file into a format that it likes, i.e., perhaps replacing ...
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3answers
186 views

DNA results from Ancestry

A friend of mine took a DNA test with Ancestry.com a while back. Now I (a trained mathematician) am being asked to help interpret the results, and I am finding myself totally out of my depth. The ...
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2answers
3k views

Is this close family member on AncestryDNA a half sibling?

on ancestry.com i got a "close family" match, with 1,430 centimorgans shared across 58 DNA segments - it says it could be a niece, aunt, or half sibling (range includes 1st cousin, but i have read ...
3
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1answer
167 views

Why would I match someone in a region neither of my parents do?

I was surprised to find someone show up in FTDNA as a 2nd-3rd cousin to me (168 shared cM, 34 segments with a minimum length of 5 cM) but not among the 17,667 matches of my father or the 18,178 ...
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1answer
307 views

half-sibling's child listed as 1st/2nd cousin

A child of a half-sibling has been determined to be a 1st or 2nd cousin; and the explanation is that variability to four degrees. Is it possible that the half-sibling status with his mother creates ...
0
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1answer
112 views

Finding biological father and half siblings in Spain using DNA?

I am 56 years old and I recently received negative paternity results from a spanish court appointed lab in Sevilla , Spain regarding half siblings, biological father is deceased. My mother will not ...
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1answer
139 views

Evaluating Ancestry DNA match to clarify Half Sibling relationships?

I did the Ancestry DNA an had a match of 1671 to a person I did not know. My sister did the test and matched him at 1251. My father believes he has a son he does not know and the stories seem to add ...
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1answer
123 views

How to help adoptee find her father without outing him?

I provide a lot of background, which may not all be essential. Feel free to skip to the question. Background I was contacted by a woman who got a 3rd cousin match with me online. She told me that ...
2
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1answer
5k views

Is this a half niece/uncle relationship vs 1st cousin once removed, or something else?

I've been in search of my deceased father's biological family. He was placed for a closed adoption 60+ years ago. I've discovered the two families who parented him thanks to Ancestry DNA matches. ...
0
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1answer
79 views

How does this cousin have NO relation to other cousin? [closed]

My husband and two of his cousins had their DNA done. Cousin A comes back as 1st cousin (as he should) cousin B comes back as distant 6th-8th cousin. Cousin A and B have NO relation. Cousin B ...
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1answer
1k views

Can half-siblings show different relationships to extended family?

My husband has found a half sibling, first on Ancestry showing a match of 1542 cm over 77 segments, and then confirmed on 23andme with a suggested relationship of "half sibling". Ancestry only showed "...
0
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1answer
51 views

Using DNA to prove parentage?

I am the biological mother of a woman born in 1967. To substantiate birth records for her and to prove that I am her biological mother, what is BEST DNA testing?
5
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3answers
690 views

Strategies for finding biological grandparents using DNA matches?

I need some advice to help track down my biological grandmother. My father was adopted in 1920 and died in 2000 without knowing the identity of his biological parents. I have his birth certificate but ...
4
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1answer
4k views

Total centimorgans vs shared dna segments?

What is the relevance of the amount of shared DNA segments? Example: I have a match that is from my adopted grandmother's family. The match shares 167 cMs over 12 DNA segments. I typically use DNA ...
3
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1answer
313 views

Taking endogamy into account when analyzing DNA matches?

How can I be certain how closely I actually relate to my cousin matches when I know that I have a person in my tree who is my 4th Great Aunt on my Father's Maternal side. This same person is possibly ...
0
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1answer
67 views

Identifying which husband of my great grandmother my father came from

My father was adopted. I believe that I have located his mother. Her father is my GREAT GRANDMOTHER's first husband. I have tested 3 1st cousins once removed??(Female 1 cm=673 on 29seg/female 2 cm=...
0
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1answer
86 views

Seeking DNA test to identify region or tribe for Native American ancestry?

I have done an Ancestry.com DNA test that revealed 32% Native American. I was looking for a specific region or tribe--searching for my great-grandmother, who was native american. my grand father is ...
6
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1answer
267 views

Is longest cM a better predictor of relatedness than total cM for Ashkenazi Jews?

As an Ashkenazi Jew, I'm used to matches being predicted to be closer than they really are. My father recently got a match to an adoptee of 348.3 shared cM, with a longest segment of 57.4 cM (...
3
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1answer
360 views

How to interpret my having ethnicities inconsistent with my parents?

According to MyHeritage's interpretation of our 23andme lab results: My father is 93.7% European (90.5% Ashkenazi, 2% Baltic, and 1.2% Italian), 5.5% West Asian, and .8% Central Asian. My mother is ...
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1answer
107 views

How likely is it that I am related to a specific person who was living 20 or 30 generations ago? [duplicate]

I have discovered that I am related to someone specific who lived in 1066. How likely is this? In other words, the answer could be “No big deal. When you go back that many generations,the math shows ...
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1answer
60 views

find relatives in-common or not-in-common based on multiple people?

Out of the hundreds of DNA relatives that show up I only recognize a few. My paternal grandfather's side is a complete mystery; I haven't found one person I recognize from what I know of my family ...
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2answers
814 views

Different genetic relation strength through maternal vs paternal line?

Is there a different genetic relation strength through maternal vs paternal line? In other words: am I more related to my mother than to my father or are they exactly equal? Or another way to ask it ...
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1answer
324 views

Using DNA data on different genealogy sites?

I had my DNA tested through a third party, independent (i.e.: not one of the main genealogy sites) lab. I have my results from them but want to upload them to the main site that I use (myheritage.com, ...
6
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4answers
312 views

Is birthmother sharing only 1549 centimorgans possible?

I'm adopted. I found my birthmother over 20 years ago. After a DNA test it shows we share 1549 centimorgans over 51 DNA segments. Is it possible that the DNA test had inaccurate results while ...
5
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2answers
414 views

Using “shared DNA” column in 23andme for triangulation?

On the 23andme site when you compare dna with a relative there is a column labeled "Shared DNA" and the description on their site says Shared DNA means that you and your two genetic relatives share ...
5
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1answer
597 views

I'm a 2nd cousin to someone, my brother is a distant cousin?

My brother and I have both been tested on 23andme. There are many people that show up at different relationships and I'm trying to understand how there can be large differences in predicted ...
2
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1answer
139 views

Seeking tools to analyse 23andme raw data?

I recently got my ancestry genetic test done from 23andme. I am interested in finding out more about my raw data. Does anybody know of some good tools that come for a good price and give me the ...
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3answers
3k views

Half Siblings not showing up as DNA matches?

I am managing the DNA accounts of my adopted brother. He has been tested directly with Ancestry and 23andMe. In 2017 FTDNA was allowing users to upload their raw dna data for a fee, and they would be ...
7
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1answer
297 views

Explaining major discrepancy in genomic position between Gedmatch and MyHeritage?

I have identified a discrepancy with several test kits that were tested at Ancestry, with results transferred to both Gedmatch and MyHeritage, all relating to the same area at the end of chromosome 19....
8
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3answers
236 views

Using shared cM to determine likelihood of misattributed paternity?

My ancestor Harriet Smith was born in the mid-1850s in England. Her birth certificate shows both of her parents (John Smith and Sarah Johnson). For the purposes of the birth registration, John and ...
3
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1answer
123 views

Are We Closer Kin Than First Cousins?

I had a match on Ancestry of a lady who was adopted as a baby, who is looking for her birth parents. She is my age. She matched at 1111 across 45 DNA segments! I know that is in range that is more ...
0
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1answer
997 views

Determing if DNA match is half sibling or 1st cousin?

The person in question matches a known aunt with 1718 cM and 56 segments. He matches a known 1st cousin with 967 cM and 49 segments. He matches another relative with 2057 cM and 57 segments. Could ...
0
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1answer
213 views

Tracing African relative based on autosomal DNA results?

I DNA tested my 3 children and one son shows as 1% Benin/Togo, my ex-father in law has also tested and he shows having SE Bantu. I am guessing 1% means about 10 generations back? Between my ex-in laws ...
2
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2answers
619 views

Should Male or Female Sibling Take DNA Test?

My sister and I are looking to do a DNA test to aid in our genealogy research. What is best practice here? Would one of us provide better results or will they be the same?
5
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2answers
136 views

Can group of matches on same segment with cM value in mid 20s be out-of-range?

WARNING: This is a question that involves endogamous genetic genealogy. (Not applicable to "normal" or "standard" DNA evaluation). I am still struggling to find some statistical limits/boundaries for ...
2
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1answer
2k views

How many CentiMorgans would a half 2nd cousin be?

I have a cousin who is adopted. I am related on her father's side, but we don't know who he is. Ancestry says she and I share 250 cM in 12 segments, Gedmatch says 255.2 cM in 11 segments. She shows up ...
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2answers
74 views

Is it possible for DNA from two male cousins to appear to have the same father in the sibling test?

If a buccal swab is taken from a cousin of a man. (ie his uncle's son) and it was compared to that man's DNA in a sibling test, would it be possible for a false positive test result showing that ...
0
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1answer
134 views

Half brother and sister related to other family?

After taking an AncestryDNA test, I matched a half brother, who I'll refer to as Y to preserve privacy, and sister, who I'll refer to as X. Both appear to come from the maternal side (both adopted ...
0
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1answer
140 views

Helping my son find his unknown biological father

My son's biological father and his family is unknown. Both my son and I took Ancestry DNA tests. Then I went through his matches for "shared matches" - if I didn't show up, I assumed the match was ...
2
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0answers
738 views

Is the relationship an aunt /niece or half sister to my mother?

I am a genetics beginner: A little back story: My mother was adopted at birth. She found her birth mother and siblings back in the 90s. The birth mother was deceased at the time, and we also ...
4
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3answers
722 views

Trying to find father using AncestryDNA?

I'm trying to help my friend find out who her biological father is. She currently has no clue. Our starting point is that she has taken an Ancestry DNA test and so has access to some 2nd and 3rd ...
0
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1answer
103 views

Could be half brother?

I recently received my DNA match from Ancestry we share 757 centimorgans shared across 35 DNA segments. Could this be a half brother instead of 1st cousin like it predicts? I have no history of my ...
2
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1answer
162 views

How to filter and sort MyHeritage DNA matches?

I'm relatively new to MyHeritage. And I'm having a hard time figuring out how to manage all my DNA matches. (The help center-DNA maches shows no help and there appears to be no MyHeritage forum for ...
2
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1answer
804 views

Explaining DNA mystery of unexpected 1st cousin?

I wanted someone to confirm my thoughts or give me some guidance. I have uncovered a possible 1st cousin mystery dna match. (ancestry)( I know all my first cousins and no one has done a dna test.) ...
5
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1answer
548 views

Why are MyHeritage atDNA SNPs higher than other test sites?

I have accumulated DNA segment match information from ftDNA, GEDmatch, and MyHeritage. It is just recently that I've added MyHeritage DNA donors data, and I've found that the total number of matching ...
5
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2answers
683 views

Determining shared maternal or paternal lineage via shared DNA segments?

If DNA cousins and I share the exact same segment of DNA, does it always mean we're related via the same side of the family? Background: I have taken DNA tests with National Geographic, Ancestry, ...

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