Health Results from 23andme

When I first discussed with my daughter, Liz, that I wanted to submit a sample to 23andme, we discussed her concerns.  First of all, she is a Genetic Counselor.  Secondly, there is a bit of a debate within the Genetic Counselor community about the wisdom of "direct to consumer" DNA analysis.  Will the typical consumer be able to understand the results (much less be able to deal with potentially negative results)?  After all, that is what Genetic Counselors do.  There are genes that have been identified that are associated with breast cancer.  Worse yet, what if an analysis shows that you have a gene that will definitely lead to an early death -- like Hungtington's.  Do you really want to know that your genes predict that you are likely to develop Alzheimer's?  What about Parkinson's?  All of these are possibilities and something you should consider.

I am 62 years old.  I already have experienced some significant health issues.  Would the results support what I already know?  In my family, there is a significant history of cancer.  We all "assume" that that is what will eventually kill us.  Quite a few relatives have developed macular degeneration.  And the bigger question -- how strong is the science behind 23andme's health predictions?

I told my daughter that if she didn't want to know the results, I wouldn't share them.  She said she didn't think I could keep my mouth shut.  Even if I could, she wasn't sure that she could stand "not knowing" if I knew.  I decided I was going to do it anyway.

Well the results came.  I was pleasantly surprised.  For one thing, they let you know whether or not you are a "carrier" for genes that are responsible for things like cystic fibrosis, sickle cell, etc.  I found out that I was not a carrier for any one of them!  What a nice thing to know.  You can click on each disease for a description of what it is.  The yellow stars indicate the level of confidence in the research that backs up the prediction.  Not only that, but you can be referred to the specific studies that identified the gene.  Here are some of my results.

Needless to say I was consoled by these results.  Of course if my results showed that I was a carrier, I may have felt differently.  In my next post, I will discuss a few of their predictions for disease and how closely the results correlated with what I know about my health status.

Anticipating DNA Results

So you send your sample in for testing and then you wonder what kind of results you might get.  Everyone knows that we inherit half of our DNA from our mother and half from our father.  Knowing this, it is logical that 25% of our DNA would come from each of our four grandparents.  The waters get a little muddier with siblings, aunts, uncles and cousins.  I found this great graphic on Wikipedia that helps make it clear. (All graphics can be enlarged by clicking on them).



Graphic Credit: Dimario, Wikipedia Commons

The Human Genome Project determined that humans share 99.9% of their DNA in common, although this exact percentage has recently been challenged.  This means that all of the diversity among humans comprises a relatively small part of our entire genome.  Since I'm not aware that any of my close relatives have been tested (yet) and I know most of my close relations, I really didn't expect to find any "cousins" that would fall within the second cousin category or closer -- and I didn't.  Here is what I did discover.

Unlike FamilyTreeDNA, 23andme scans all of your genome to look for patterns that may be used to predict your ancestry.  Mine turned out to be 100% European.  No surprise there.  Here are my results.

I really didn't understand this graphic until I compared it to a graphic for someone that had more of a mixed inheritance pattern.  Here is a sample for an African-American man.

I find it interesting that, as is the case with so many African-Americans, a lot of this man's ancestry is European in origin.  You can go to 23andme, create a free account and explore other sample groups under "Ancestry Painting."

When 23andme compared me to others in their database, the closest relationship they could identify for me was a potential 4th cousin. You can see from the table posted above that I would not anticipate sharing much of my DNA with this person.  23andme computed that we shared 0.48% of our DNA -- big whoop!!! (Note:  I've since found out that the 36 cM we share is a big deal.  Who knew).  Here is what we share in common.

You are reading it correctly.  We share one little section on chromosome 20.  I'll bet I share that much with my husband.  I guess I'm going to have to have him submit a sample.  So come on, cousins, submit a sample!  I want to have some fun.

In my next post, I'll discuss what I found out from a medical point of view.

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.