Tuesday, April 24, 2018
Understanding Our DNA Tests
Nadene Goldfoot
Edited by Dr. Sandra Oster
We have 23 chromosomes that carry our genes. The chromosomes are like steps on a ladder, with #1 being the widest step that holds the most genes. The 23rd and last step is called either the X match which means they have a female match in common or a Y match meaning they have a male match in common. It's the sex gene which determines our own sex. Females have XX. Males have XY. The Y chromosome has the fewest genes; only 231.
All 23 rungs on the ladder which stand for the 23 chromosomes we have carry double amounts in 2 rows. One row is from our father and the other from our mother. It's pretty close to being even; 50-50. Our test from FTDNA has been identifying if a match is from either parent with a little icon of a blue male or red female or purple from both; like the child would have. Some people cannot be decided on and get no icon by their name/picture.
The genes come to us in little 1cM blocks, like a single Lego block. In genetics, a centimorgan is a measurement for distance. It is (abbreviated cM) or map unit (m.u.) is a unit for measuring genetic linkage. It is defined as the distance between chromosome positions (also termed loci or markers) for which the expected average number of intervening chromosomal crossovers in a single generation is 0.01. The thing is, they usually come to us stuck together with others, making a longer block called a segment. The longer the segment, the closer you are to the person you match with them. 1 lego block is 1cM.
The ladder is seen by the scientists as a twisted ladder, the shape of a double helix.
Here's my test result with a 1st paternal cousin.
Notice the segments are pretty long, several on one chromosome. #1 chromosome has 4 segments.
I don't worry about the SNPs (Single Nucleotide Ploymorphisms.) They are a very slowly mutating location that is used to define haplogroups, another factor of genetics. That is important in identifying the clans your father or your mother belonged to.
The largest segment is on #9 chromosome. of 52.1cMs. Look below at chromosome #9. It's a picture of the largest segment being in this case, a long one of 52.1. It a length of 52.1 little blocks stuck together.
The smallest segment is on #21 of 7.5cMs.
A segment of 5cMs and more is counted as an important fact. Some people only get interested in the facts with a segment of 7cMs and more. . Smaller segments are not too important, possibly thought of as not as reliable scientifically.
The graph on FTDNA showing #1 chromosome match between my 1st cousin and myself: This black and yellow length is a chromosome with yellow segments on it and is the first chromosome called #1. When you are on your page in Family Tree DNA's website, you would see this and all the other 22 chromosomes. I'm showing you this one because the table below shows 4 large segments on #1 chromosome listed separately with the start and end location and how many cMs they have as well as how many SNPs that chromosome has..
The Table-below
Largest segment = 52.1 cM
Total of segments > 7 cM = 837.6 cM
37 matching segments
Estimated number of generations to MRCA = 2.0 MOST RECENT COMMON ANCESTOR
Here's the test with the same cousin and my daughter to see what she inherited .
How did she match the #3 chromosome? I didn't have a match on #3 so how could she inherit it from me? I thought I pass genes to my daughter. How did she inherit 7.1cMs on chromosome number 3? Wouldn't they have come from her father, then?
She inherited some segments in the same piece that I passed to her, but most had lost some cMs.in the passing to her.. She gained #3's matching chromosome segment that I didn't have, I thought.
My son did not have a match with my 1st cousin on #3.
Largest segment = 35.7 cM
Total of segments > 7 cM = 398.8 cM
23 matching segments
Estimated number of generations to MRCA = 2.6
My brother had inherited 2 large segments on chromosome #3 .They aren't the same segments that I had matched with our cousin and are big ones, too. Siblings don't always match the same segments with other people just because they are siblings.
.
Our Goldfoot Family Tree
Notice the unusual names below. They are how our ancestors were listed in the Lithuanian records. Every 10 years or so their names appeared in a different spelling of the first letter. ben means son of, which helped to identify their parents.
1 Iankel Yankel ben Abram Goldfusb: 1768 in Telsai, Telsiai, Kaunas, Lithuaniad: December 06, 1860 in Telsliai, Telsiai, Kaunas, Lithuania
..+Khana Unknownb: Abt. 1778 in Telsiai, Telsiai, Kaunas, Lithuania
.2 Abram Goldfusb: Abt. 1797 in Telsiai, Telsiai, Kaunas, Lithuania
.....3 Mendel Goldfusb: 1800
.....3 Leyba Abramov Goldfusb: 1819 in Papile, Siauliai, Kaunas, Lithuania
.........+Feyge Ioselevab: 1820
.....3 Ginda Abramovna Goldfusb: Abt. 1820 in Telsiai, Lithuaniad: January 15, 1869 in Telsiai, Lithuania
.....3 Golda Abramovna Goldfusb: 1836 in Telsiai, Lithuaniad: April 12, 1911 in Telsiai, Lithuania
.2 [3] Iosel Josel Symka ben Yankel Goldfusb: 1798 in Telsiai, Telsiai, Kaunas, Lithuania, Russiad: December 19, 1878 in Telsiai, Telsiai, Kaunas, LithuaniaOccupation: 1851 3rd guild merchant;
.....+Rashab: Abt. 1798 in Telsiai, Telsiai, Kaunas, Lithuania, Russiad: Bef. 1876 in Telsiai, Lithuania
.....3 [1] Avrohom Abraham Haim Goldfusb: Abt. 1820 in Telsiai/ Vilna, LithuaniaOccupation: Corn Merchant into Moscow
Our 3rd cousin match goes back to Iankel Yanken ben Abram Goldfus as his gggrandfather.
My 1st cousin and I go back to Iosel Josel Symka ben Yankel Goldfus as our gggrandfather. Iosel is the son of Iankel.
2 generations ago; grandfather-your father's father or your mother's father ...2 grandmothers, 2 grandfathers
3 generations ago; ggrandfather- your grandfather's father...... 4 ggrandmothers, 4 ggrandfathers
4 generations ago; gggrandfather-your ggrandfather's father 8 gggrandmothers, 8 gggrandfathers
5 generations ago; ggggrandfather: the white circle in the chart below, needed to find 4th cousins. Your gggrandfather's father. 16 ggggrandmothers and 16 ggggrandfathers
Chart to Find 4th Cousins
Our 3rd cousin, another Goldfoot, matches like this:
1. Find your circle which is black. Your father is above YOU in green. His father is above the green and is red.
2. The red circle is your grandfather. Your father's brother had a child which is also green and labeled as 1C (first cousin).
3. To find a 2nd cousin, you must go to your grandfather's father which is blue on the chart.
The child of his brother would be the first cousin of your father's brother.
1C in the white circle's child is your 2nd cousin (2C).
On the above chart one can see how to locate a 1st, 2nd, 3rd and even a 4th cousin. Therefore, to find our 3rd cousin on our tree, we have to look at our gggrandfather (the orange) who is the father of our ggrandfather and his descendants. Iosel or Josel Symka ben Yankel Goldfus born 1798 should be our common ancestor.
Matching my 1st cousin
TRIANGULATION-on chromosome 2
216,044,195.......................................................................241,324,642 3rd cousin (47.8cMs)
193,071,967.................................... ...................219,949,518 my daughter(27.9cMs)
193,725,959...............................................................223,565,798 Me ( 33.9cMs)
When you share the same segment with 2 other people, this is called a triangulation.
You use triangulation in seeing who is part of your family.
Largest segment = 47.8 cM
Total of segments > 7 cM = 144.8 cM
8 matching segments
Estimated number of generations to MRCA = 3.3
Research: https://www.mrsec.psu.edu/sites/mrsec.psu.edu/files/dna_determines_your_appearance.pd
Book: DNA & Genealogy by Colleen Fitzpatrick & Andrew Yeiser
Edited by Dr. Sandra Oster
 |
| Think of our genes (which are a unit of heredity that is transferred from a parent to offspring and is held to determine some characteristic of the offspring.) sitting on a ladder with 23 pairs of rungs called chromosomes. One slat on the rung is from your mother, the other from your father. The first rung, called #1 is the widest rung on the ladder. It has 2,968 genes. There are 890 known diseases related to this chromosome. Some of these diseases area: hearing loss, Alzheimer disease, glaucoma and breast cancer. |
All 23 rungs on the ladder which stand for the 23 chromosomes we have carry double amounts in 2 rows. One row is from our father and the other from our mother. It's pretty close to being even; 50-50. Our test from FTDNA has been identifying if a match is from either parent with a little icon of a blue male or red female or purple from both; like the child would have. Some people cannot be decided on and get no icon by their name/picture.
 |
| Myself with two 1st paternal cousins. Only one has tested so far. The test from GedMatch.com shows we are a 2 generation match. True, we go back to our grandparents to find the common match. Our parents were siblings; my father with their mothers. Our grandparents had had 5 children with one who had died in infancy. |
Notice the segments are pretty long, several on one chromosome. #1 chromosome has 4 segments.
I don't worry about the SNPs (Single Nucleotide Ploymorphisms.) They are a very slowly mutating location that is used to define haplogroups, another factor of genetics. That is important in identifying the clans your father or your mother belonged to.
The largest segment is on #9 chromosome. of 52.1cMs. Look below at chromosome #9. It's a picture of the largest segment being in this case, a long one of 52.1. It a length of 52.1 little blocks stuck together.
The smallest segment is on #21 of 7.5cMs.
A segment of 5cMs and more is counted as an important fact. Some people only get interested in the facts with a segment of 7cMs and more. . Smaller segments are not too important, possibly thought of as not as reliable scientifically.
The graph on FTDNA showing #1 chromosome match between my 1st cousin and myself: This black and yellow length is a chromosome with yellow segments on it and is the first chromosome called #1. When you are on your page in Family Tree DNA's website, you would see this and all the other 22 chromosomes. I'm showing you this one because the table below shows 4 large segments on #1 chromosome listed separately with the start and end location and how many cMs they have as well as how many SNPs that chromosome has..
| Chr | Start Location | End Location | Centimorgans (cM) | SNPs |
| 1 | 3,052,221 | 25,801,522 | 44.8 | 6,612 |
| 1 | 53,581,281 | 69,237,989 | 22.1 | 4,484 |
| 1 | 74,788,735 | 90,271,128 | 14.6 | 3,815 |
| 1 | 149,227,054 | 163,867,989 | 21.2 | 4,088 |
| 2 | 84,202,139 | 106,046,373 | 10.3 | 3,041 |
| 2 | 193,725,959 | 223,565,798 | 33.9 | 6,378 |
| 2 | 223,581,059 | 233,766,809 | 14.4 | 2,341 |
| 4 | 61,566 | 6,048,415 | 10.4 | 1,413 |
| 4 | 139,776,818 | 173,159,377 | 34.4 | 6,286 |
| 5 | 2,711,026 | 9,426,448 | 17.1 | 2,343 |
| 5 | 29,372,002 | 55,864,542 | 23.0 | 4,971 |
| 5 | 153,966,655 | 180,623,543 | 45.7 | 6,994 |
| 6 | 3,653,477 | 20,272,175 | 32.2 | 4,958 |
| 6 | 74,007,746 | 91,078,586 | 10.5 | 3,373 |
| 6 | 126,393,744 | 137,403,363 | 11.6 | 2,349 |
| 6 | 154,838,664 | 161,802,211 | 9.6 | 2,104 |
| 7 | 29,887,885 | 45,266,280 | 19.7 | 3,835 |
| 8 | 6,006,187 | 12,761,447 | 11.6 | 1,917 |
| 8 | 23,060,574 | 31,234,783 | 11.9 | 2,354 |
| 8 | 103,773,672 | 125,812,954 | 19.0 | 4,408 |
| 9 | 81,797,685 | 123,377,583 | 52.1 | 10,912 |
| 9 | 124,006,082 | 134,328,607 | 15.2 | 2,497 |
| 10 | 85,994,218 | 103,089,567 | 16.5 | 4,577 |
| 10 | 128,065,109 | 135,297,961 | 18.9 | 2,714 |
| 12 | 116,636,547 | 124,168,929 | 9.3 | 1,758 |
| 14 | 30,341,495 | 42,197,431 | 16.8 | 2,771 |
| 14 | 89,899,082 | 106,345,097 | 34.6 | 4,453 |
| 15 | 18,331,687 | 40,097,819 | 42.3 | 5,070 |
| 16 | 64,956,434 | 80,257,464 | 22.4 | 4,230 |
| 17 | 12,344 | 7,964,962 | 22.0 | 2,537 |
| 18 | 6,414,209 | 32,274,392 | 40.6 | 6,428 |
| 18 | 71,869,832 | 74,401,062 | 8.0 | 971 |
| 19 | 3,713,698 | 33,398,855 | 36.2 | 5,038 |
| 20 | 57,539,142 | 62,374,274 | 16.5 | 1,588 |
| 21 | 9,849,404 | 16,035,905 | 7.5 | 569 |
| 21 | 16,591,440 | 35,444,863 | 32.8 | 5,231 |
| 22 | 37,722,196 | 49,528,625 | 28.0 | 3,818 |
Total of segments > 7 cM = 837.6 cM
37 matching segments
Estimated number of generations to MRCA = 2.0 MOST RECENT COMMON ANCESTOR
Here's the test with the same cousin and my daughter to see what she inherited .
How did she match the #3 chromosome? I didn't have a match on #3 so how could she inherit it from me? I thought I pass genes to my daughter. How did she inherit 7.1cMs on chromosome number 3? Wouldn't they have come from her father, then?
She inherited some segments in the same piece that I passed to her, but most had lost some cMs.in the passing to her.. She gained #3's matching chromosome segment that I didn't have, I thought.
My son did not have a match with my 1st cousin on #3.
| Chr | Start Location | End Location | Centimorgans (cM) | SNPs |
| 1 | 3,025,087 | 12,086,665 | 19.3 | 2,788 |
| 1 | 74,942,731 | 90,347,366 | 14.6 | 3,835 |
| 1 | 149,581,003 | 163,732,848 | 20.9 | 3,965 |
| 2 | 82,974,238 | 106,005,245 | 10.8 | 3,251 |
| 2 | 193,071,967 | 219,949,518 | 27.9 | 5,530 |
| 3 | 36,495 | 2,749,996 | 7.1 | 1,097 |
| 4 | 139,776,818 | 173,159,377 | 34.4 | 6,299 |
| 5 | 29,249,005 | 36,391,583 | 11.1 | 1,897 |
| 5 | 153,879,500 | 172,829,402 | 29.0 | 4,943 |
| 6 | 3,362,642 | 19,807,420 | 32.4 | 4,877 |
| 6 | 126,393,744 | 137,332,306 | 11.5 | 2,347 |
| 6 | 154,838,664 | 161,802,211 | 9.6 | 2,129 |
| 8 | 23,253,923 | 31,234,783 | 11.5 | 2,309 |
| 8 | 117,536,189 | 125,770,106 | 11.4 | 2,082 |
| 10 | 85,614,149 | 99,641,440 | 13.5 | 3,854 |
| 10 | 127,998,547 | 135,297,961 | 19.1 | 2,761 |
| 14 | 89,499,502 | 106,345,097 | 35.7 | 4,560 |
| 15 | 34,667,910 | 40,092,334 | 8.1 | 1,498 |
| 16 | 64,462,524 | 80,294,248 | 23.0 | 4,475 |
| 18 | 6,414,209 | 9,689,833 | 13.6 | 1,233 |
| 18 | 71,869,832 | 74,397,540 | 8.0 | 986 |
| 21 | 9,849,404 | 16,035,905 | 7.5 | 568 |
| 21 | 16,285,114 | 26,701,936 | 19.2 | 2,892 |
Total of segments > 7 cM = 398.8 cM
23 matching segments
Estimated number of generations to MRCA = 2.6
My brother had inherited 2 large segments on chromosome #3 .They aren't the same segments that I had matched with our cousin and are big ones, too. Siblings don't always match the same segments with other people just because they are siblings.
.
| 3 | 3,391,536 | 44,079,879 | 56.6 | 11,481 |
| 3 | 129,663,879 | 193,357,386 | 74.4 | 13,730 |
Our Goldfoot Family Tree
Notice the unusual names below. They are how our ancestors were listed in the Lithuanian records. Every 10 years or so their names appeared in a different spelling of the first letter. ben means son of, which helped to identify their parents.
1 Iankel Yankel ben Abram Goldfusb: 1768 in Telsai, Telsiai, Kaunas, Lithuaniad: December 06, 1860 in Telsliai, Telsiai, Kaunas, Lithuania
..+Khana Unknownb: Abt. 1778 in Telsiai, Telsiai, Kaunas, Lithuania
.2 Abram Goldfusb: Abt. 1797 in Telsiai, Telsiai, Kaunas, Lithuania
.....3 Mendel Goldfusb: 1800
.....3 Leyba Abramov Goldfusb: 1819 in Papile, Siauliai, Kaunas, Lithuania
.........+Feyge Ioselevab: 1820
.....3 Ginda Abramovna Goldfusb: Abt. 1820 in Telsiai, Lithuaniad: January 15, 1869 in Telsiai, Lithuania
.....3 Golda Abramovna Goldfusb: 1836 in Telsiai, Lithuaniad: April 12, 1911 in Telsiai, Lithuania
.2 [3] Iosel Josel Symka ben Yankel Goldfusb: 1798 in Telsiai, Telsiai, Kaunas, Lithuania, Russiad: December 19, 1878 in Telsiai, Telsiai, Kaunas, LithuaniaOccupation: 1851 3rd guild merchant;
.....+Rashab: Abt. 1798 in Telsiai, Telsiai, Kaunas, Lithuania, Russiad: Bef. 1876 in Telsiai, Lithuania
.....3 [1] Avrohom Abraham Haim Goldfusb: Abt. 1820 in Telsiai/ Vilna, LithuaniaOccupation: Corn Merchant into Moscow
Our 3rd cousin match goes back to Iankel Yanken ben Abram Goldfus as his gggrandfather.
My 1st cousin and I go back to Iosel Josel Symka ben Yankel Goldfus as our gggrandfather. Iosel is the son of Iankel.
Definition of words:
1, A generation: about 25 years2 generations ago; grandfather-your father's father or your mother's father ...2 grandmothers, 2 grandfathers
3 generations ago; ggrandfather- your grandfather's father...... 4 ggrandmothers, 4 ggrandfathers
4 generations ago; gggrandfather-your ggrandfather's father 8 gggrandmothers, 8 gggrandfathers
5 generations ago; ggggrandfather: the white circle in the chart below, needed to find 4th cousins. Your gggrandfather's father. 16 ggggrandmothers and 16 ggggrandfathers
Chart to Find 4th Cousins
1. Find your circle which is black. Your father is above YOU in green. His father is above the green and is red.
2. The red circle is your grandfather. Your father's brother had a child which is also green and labeled as 1C (first cousin).
3. To find a 2nd cousin, you must go to your grandfather's father which is blue on the chart.
The child of his brother would be the first cousin of your father's brother.
1C in the white circle's child is your 2nd cousin (2C).
On the above chart one can see how to locate a 1st, 2nd, 3rd and even a 4th cousin. Therefore, to find our 3rd cousin on our tree, we have to look at our gggrandfather (the orange) who is the father of our ggrandfather and his descendants. Iosel or Josel Symka ben Yankel Goldfus born 1798 should be our common ancestor.
Matching my 1st cousin
TRIANGULATION-on chromosome 2
When 3 people share a segment, showing they are all from the same family group.
193,071,967.................................... ...................219,949,518 my daughter(27.9cMs)
193,725,959...............................................................223,565,798 Me ( 33.9cMs)
When you share the same segment with 2 other people, this is called a triangulation.
You use triangulation in seeing who is part of your family.
| Chr | Start Location | End Location | Centimorgans (cM) | SNPs |
| 2 | 28,614,418 | 34,742,899 | 8.6 | 1,844 |
| 2 | 216,044,195 | 241,324,642 | 47.8 | 6,719 |
| 5 | 55,766,345 | 84,196,459 | 30.1 | 6,133 |
| 9 | 134,011,429 | 140,145,149 | 19.5 | 1,893 |
| 10 | 92,947,202 | 101,347,625 | 8.7 | 2,332 |
| 11 | 129,114,448 | 131,952,204 | 8.6 | 1,013 |
| 14 | 42,939,019 | 57,527,999 | 14.5 | 3,564 |
| 17 | 45,683,412 | 51,515,464 | 7.1 | 1,391 |
Total of segments > 7 cM = 144.8 cM
8 matching segments
Estimated number of generations to MRCA = 3.3
Research: https://www.mrsec.psu.edu/sites/mrsec.psu.edu/files/dna_determines_your_appearance.pd
Book: DNA & Genealogy by Colleen Fitzpatrick & Andrew Yeiser
Labels: chromosomes, generations to MRCA, segments
