DNAprint Genomics (DNAG)

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Someinteresting stuff:

BioGeographical Ancestry (BGA) Testing

I wish to thank Dr. Matt Thomas of http://www.dnaprint.com for a very informative discussion about the DNAPrint results.
The BGA test determines the probable fractions of one's ancestry that are Indo-European (European, Middle Eastern and South Asian), Native American (South and North American), sub-Saharan African (all African countries but Algeria, Chad, Egypt, Morocco, Sudan and Tunisia) and East Asian (Japanese, Chinese, Korean and South Pacific).
Here is a way to interpret the probabilities that one gets for the different BioGeographical Ancestries (n=ancestral generation):
(n=1): Suppose one has one parent that is 100% BGA #1 and one that is 100% BGA #2: Then he/she is 50% BGA1 and 50% BGA2. (One side of his/her two chromosome strands is BGA1 and the other side is BGA2. In the process of producing progeny the two strands of the chromosome will equally mix up so that each strand of the chromosome is 50% BGA1 and 50% BGA2.)
(n=2): Suppose one has three grandparents that are 100% BGA1 and one that is 100% BGA2: Then he/she is 75% BGA1 and 25% BGA2. (One side of his/her two chromosome strands is BGA1 and the other side is 50% BGA1 and 50% BGA2. In the process of producing progeny he/she will equally mix up the two strands of the chromosome, so that there are various possible combinations of BGA1 and BGA2 genes in each strand of a chromosome, with the most probable combination being 25% BGA2 in one strand and 25% BGA2 in the other strand. This introduces some uncertainty in the amount of BGA2 his/her progeny will have, but the uncertainty is very small for the approximately 60,000 human genes.)
(n=3): Suppose one has seven great-grandparents that are 100% BGA1 and one great-grandparent that is 100% BGA2: Then he/she is 87.5% BGA1 and 12.5% BGA2 to a high degree of certainty, but he/she could have smaller than 12.5% BGA2.
(n=4): Suppose one has fifteen great-great-grandparents that are 100% BGA1 and one that is 100% BGA2: Then he/she is 93.75%% BGA1 and 6.25% BGA2.
(n=5): Suppose one has thirty-one great-great-great-grandparents that are 100% BGA1 and one that is 100% BGA2: Then he/she is 96.875% BGA1 and 3.125% BGA2.
(n=6): Suppose one has sixty-three great-great-great-great-grandparents that are 100% BGA1 and one that is 100% BGA2: Then he/she is 98.4375% BGA1 and 1.5625% BGA2.
The analysis above assumes that the BGA2 comes from only one nearest 100%-BGA2 ancestor; it could come from more than one 100%-BGA2 nearest ancestor. In that case the ancestors would be further back in time than the analysis above indicates.

Since the errors on the BGA results are usually of the order of ±2.5% [e.g., for my result given below, my East-Asian value is (17±2.5)%], one cannot determine fractional ancestry with BGA back further than great-great-great-grandparents or back no further than 5 generations.
For my case of (17±2.5)% East Asian, BGA indicates that my 100%-East-Asian ancestor was a great-grandparent; it could be that there are two (or more) 100%-East Asian ancestors, one great-grandparent and one great-great-grandparent (12.5% + 6.25%=18.75%) or three great-great-grandparents (3 x 6.25%=18.75%).
For the case of my wife of (9±2.5)% East Asian and (2±2.5)% Native American, her East-Asian ancestor was a great-great-grandparent (or a great-great-grandparent and a great-great-great-grandparent [6.25% + 3.125%=9.375%]) and her Native-American ancestor was either a great-great-great-grandparent, a great-great-great-great-grandparent, or did not exist. (The 2.5% error could mean that the result of 2% could easily be 0%.)

This is a chart one can use to decide in which generation an ancestor is according to the percentage of ancestry given by the BioGeographical Ancestry test. For example, my (17±2.5)% East-Asian component lies closest to the great-grandparents' percentage and my wife's (9±2.5)% East-Asian component lies closest to the great-great-grandparents' percentage. Her (2±2.5)% Native-American component could be either gr-gr-gr-grandparents or gr-gr-gr-gr-grandparents or further back or none at all.

This test is managed by Family Tree DNA, but is performed by DNAPrint Genomics