Sunday, June 12, 2011

Genetic Genealogy

Photo Credit: 
U.S. National Library of Medicine
My daughter is a Genetic Counselor and I have always found her work interesting.  Part of our mutual interest in this field was the result of a diagnosis that I had inherited one copy of the gene for the Factor V Leiden mutation from either my mother or my father.  She, in turn, inherited it from me. It makes us more genetically predisposed to developing a blood clot than other members of the population -- three to ten times more likely.

Background

I was an elementary science teacher so DNA has always held a fascination for me.  I learned several years ago that the mitochondrial DNA located outside of the nucleus of a cell is passed from a mother to all of her children (male and female) largely intact.  (CeCe,  the Genetic Genealogist, reminded me that mitochondrial DNA is found outside the nucleus of the cell, whereas our chromosomes are found inside the cell nucleus.  The X chromosome is inside the cell nucleus along with the 22 other non-sex related chromosomes. You can follow the link to her article on the subject). The mitochondrial DNA travels through each generation.  Males, on the other hand, inherit one copy of their mother's mitochondrial DNA and one copy of the "Y" chromosome from their father -- that's why the 23rd chromosome is XX for females (one X from Mom and one X from Dad), while males are XY (one X from Mom and one Y from Dad).  That Y chromosome is then passed from father, to son, to grandson, etc. down the paternal line.

FamilyTreeDNA

In 2006, I convinced my brother Dan, to submit a sample to FamilyTreeDNA for analysis.  Providing my own sample would not allow me to have any results for my paternal side because, being female, I'm missing that Y chromosome.  The science was relatively new then.  They identified my maternal haplogroup as "H." Based on 25 "markers" for the Y chromosome, the paternal haplogroup was identified as R1B1a.  Bottom line: Both my maternal and paternal haplogroups are very common in Europe -- especially northwest Europe.

23andme

I'd pretty much left my "genetic genealogy" in a file folder as it didn't seem to tell me anything I didn't already know through from years of old-fashioned research. But then I read that I could send a sample to 23and me and not only get some genealogical information but a whole lot of health information, too.

What you need to know about me!

#1 - I'm cheap! (or should I say frugal).  I'll think long and hard before parting with my money.

Photo Credit:  ehow.com
#2 - I'm skeptical!  After all, I spent years teaching my young students not to be gullible and question everything.  So I wanted to know -- what were their health predictions based upon?  Did I really want to know their predictions? How big is their database for predicting genealogical ancestry?

But this time, they made me an offer I couldn't refuse.  The actual genetic testing was FREE!  That certainly took care of concern #1.  The only obligation was for me to subscribe to their online newsletter for $9 a month for a minimum of a year.  Since I also taught math, I know that is $108 -- cheap in the scheme of things.  As to concern #2 -- I would get the results and take all of it with a grain of salt.  I could determine for myself how much weight to give the results.  And so I took the bait -- and I'm glad I did.  Over the next couple of posts, I'll discuss what I learned through this process and why I'd love to have YOU sign up.  What a discussion we could have then.

2 comments:

  1. Very Interesting.....I will do it ! Becaouse I am margaret's daughter and a little Noesy !! lol !
    Patty

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  2. Mitochondrial DNA does not come from the X-Chromosome. mtDNA is found outside the nucleus and the X-Chromosome is contained inside the nucleus with the other 22 non-sex chromosomes. Please see my post on the difference between them:
    http://www.yourgeneticgenealogist.com/2010/07/x-chromosome-testing-vs-mtdna-testing.html
    Hope you don't mind the note.
    Love your genetic genealogy series!
    CeCe

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