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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.

5
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1answer
27 views

Working with DNA results for multiple profiles across multiple sites

I manage a number of DNA profiles (for related individuals) across a number of sites: FamilyTreeDNA (5 profiles) MyHeritage (5 profiles) LivingDNA (2 profiles which will increase to 5 in the near ...
2
votes
1answer
23 views

Interpreting matches with low cM values and high SNPs (or vice versa)?

On GEDmatch's autosomal one-to-one report, a match contains a column for cM and a column for SNPs values, for each of the matching chromosomes. Normally you look for high cM values as an indicator of ...
2
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2answers
87 views

Finding Korean War-Baby Brother using GEDmatch?

My dad got a lady pregnant in Korea while he was in the war. When he got back, he tried to move her here but was unable to. He lost touch with her. For years, I have tried to find him but there was no ...
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0answers
18 views

What percentage of chinese am i? [duplicate]

If my mom is 100% filipno but my dad is 80% filipino but 20% chinese. What percentage of chinese am i?
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1answer
35 views

If my great grandmother is Half Spanish what percent does that make me? [duplicate]

My Great Grandmother is Half spanish what percent would that make me?
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0answers
27 views

Interpreting runs of homozygosity data to determine how closely parents were related?

According to Gedmatch's Are your parents related? tool, my grandmother's DNA shows several runs of homozygosity (ROH): Chr Start Location End Location Centimorgans (cM) SNPs 3 180690286 ...
1
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2answers
48 views

Perplexing Shared DNA Data - First Cousin Once Removed or Half Niece?

My sister and I recently did DNA tests through 23&Me. We found out we have a surprise relative about 27 years younger than us (a generation younger). She has about 8.5% shared DNA or around 577 ...
1
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2answers
55 views

Triangulation with DNA Results - is something amiss?

My 1st cousin 1xR and my Aunt and I have all taken Ancestry DNA tests. For clarity sake I will refer to the parties as "Z", "N" and "R" "R" is related (by document) to "N" as nephew and Aunt "Z" is ...
1
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1answer
49 views

23 and Me DNA testing finding new (close) relatives

I did 23 and Me about a year ago and found a '2nd cousin' (according to their algorithm) who put his background as 'adopted and wanted to find birth family' I reached out to him. Let's call him AJ. ...
3
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1answer
53 views

How can genetic relatives be related to both maternal and paternal sides, but not each other?

I am completely ignorant to all of the genetics of ancestry, although I have a keen interest in family history. I did a DNA test through 23andme, as did my mother and a paternal aunt. In my list of ...
2
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2answers
53 views

Is DNA match 1st cousin or niece?

I have recently learned that my father is not my biological father. Please see the Ancestry DNA screenshot. The first person in red is listed as a first cousin but I know for a fact she is actually ...
4
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1answer
30 views

Using DNA to link individuals after a name change

How do I go about using genetic testing to support (or disprove) the identity of an individual before a name change? My great-great-grandfather, Everett T Malcom, would just say, "It's me own ...
0
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2answers
54 views

How much Chinese dna will show up on my dna test

I just got my results back from My Heritage. I have a picture of my Great Great Grandfather he definitely looks Chinese, his father was 100 percent Chinese and he married a Native American they would ...
0
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0answers
50 views

DNA not supporting linear genealogy between grandparent, child and grandson?

I am his grandmother and should have 300 or more cMs connection. However, we share only 18 or so cMs. My son, (my grandson's father), shares only 17.2 cMs. What's up?
1
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2answers
54 views

Interpreting 23andMe results for half siblings that share 45.5% of their DNA?

I was raised to believe that my half sister and I were in fact half sisters with different fathers. We both did 23andMe testing and the results conclude that we share 45.5% of the same DNA. we share ...
2
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2answers
68 views

No shared X DNA segments found

On FTDNA I match two other Stephens males with the exception of 1 marker over 67 markers. When the three of us uploaded our DNA to Gedmatch, mine from FTDNA Family Finder and theirs from Ancestry, we ...
2
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1answer
45 views

Are centimorgan contributions additive?

I share a 50 centimorgan 6 segment match to person "J". My maternal side aunt shares 54 centimorgan 5 segment match to that same person "J" I see two possible blood-line connections between my aunt ...
0
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0answers
54 views

Is aunt actually mother's half sister?

I was looking at a first cousin of mine after doing the 23andme DNA test and found that we only share 5.25% of DNA with him, and it believes he is a second cousin of mine. I checked my mom's DNA ...
1
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1answer
39 views

Determining if siblings are half siblings or full siblings?

I recently found 6 siblings 4 who are half and 2 who may be full. My sister was born in 1949, I was born in 1950 and my brother in 1952. The other siblings all know who both their parents are. The ...
6
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1answer
55 views

When triangulation is not transitive

I'm focusing on triangulation groups and so looking at matching segments that overlap each other. I'm frequently finding the situation where, at a single website, match A's segment is shown as ...
5
votes
1answer
63 views

Segments with no matches

I am beginning the process of forming triangulation groups, and I wonder: what do people do with segments on which there are no matches? I found such a segment already just on the first chromosome I ...
0
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0answers
18 views

Does 2% fall into the normal range of amount of DNA shared with a first half cousin? [duplicate]

Does 2% or 142 cm amount of DNA shared with a half first cousin add up? From what I’ve read, the amount of DNA shared between two half first cousins falls between 215-650 CMs or 4-7%. My other ...
6
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1answer
112 views

Reconstructing autosomal genomes of Mayflower passengers

I imagine no group of 100 people has been as genealogically documented as the Mayflower passengers. And with an estimated 35,000,000 descendants living today, the number of descendants genetic tests ...
0
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1answer
43 views

DNA results for half sibling

I had my DNA test done about 8 years ago with ancestry, I was contacted by a person who believed he could be my half brother from my father during World War 2, all the information he had said my ...
1
vote
2answers
86 views

Half sibling or 1st cousin?

I recently did Ancesty DNA to determine a match between me and a possible half sister. The results came back, and we share 1366 cM of DNA. As I’ve learned, this is on the low side for half siblings ...
4
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1answer
35 views

Percentages of nucleotides in raw DNA

I just had Excel compute the percentage of each nucleotide appearing as the first letter in each position in a raw DNA file. Then I had it compute the percentage of each nucleotide in the second ...
5
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2answers
75 views

Triangulation conundrum

I tested both my mother "M" and her brother "D" at FTDNA. I was looking through D's list of segments today for triangulated segments, using the matrix utility to help, and I found the following D ...
3
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1answer
45 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
46 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
89 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 ...
9
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1answer
63 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
votes
1answer
53 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 ...
2
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1answer
74 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 main ...
1
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2answers
107 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
votes
1answer
108 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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votes
1answer
48 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
votes
1answer
45 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 ...
1
vote
1answer
48 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 ...
0
votes
1answer
98 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
votes
1answer
282 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
votes
1answer
69 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 ...
0
votes
1answer
128 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
45 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?
4
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3answers
129 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
votes
1answer
567 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
votes
1answer
104 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
52 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
40 views

What type of DNA test?

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
votes
1answer
64 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
votes
1answer
110 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 ...