There is a gene called CCR5 that can have a variation that prevents AIDS. You need to have two copies, one from each parent, to be immune to AIDS. If you have only one copy, your resistance is increased. The current theory is that this mutation became prevalent in Europeans after the ravages of smallpox or perhaps the Black Death and was selected for, since it is presumed protective against those diseases. It is more frequent in Northern Europe than Southern, but is found as far south as North Africa.
from wikipedia – By US National Institutes of Health – National Institute of Allergy and Infectious Diseases – US National Institutes of Health – National Institute of Allergy and Infectious Diseases, Public Domain, Link
The down side is that this CCR5 change may increase your risk of an abdominal aortic aneurysm and put you at risk for complications from various viruses like West Nile or tick born encephaliitis. Wikipedia has an excellent and detailed article about CCR5 here.
This AIDs protective variation is actually the loss of 32 alleles (so it is called delta 32) on chromosome 3 at location 46414947.
It is that change that the Genetics researcher He Jiankui claims to have made on two embryos in China using CRISPR technology which has caused such an uproar around the world. Click here for the NPR article about that which mentions that their father is HIV positive.
If you have tested your DNA at 23andme, you can check your own CCR5 for the delta 32 variation which is known as i3003626 there. Here’s how
There are a number of posts on this blog which can help you navigate 23andme (click here) but as always in life, things change. Now there are many new features and ways of finding information that are not covered by those articles. Plus the tests sold during the holiday sales are coming in and I have lots of new cousins.
The Family & Friends page – red arrows show what to click to get to the DNA relatives list from either top menu or this page
The key to using your 23andme test for finding new cousins is to navigate to the DNA relatives page and then click on each name of interest to go to the page with information about that match. The contents of that page are well covered in my previous blog post (click here)
Most importantly, you can get to the version of the chromosome browser that shows the actual segment locations and sizes from that match page. Here is why that is important.
When a new tester matched me, my dad, and several distant cousins for 33cM on a specific location on the X, I knew she was related via the Fatland farm family from Halsnøy island, Hordaland, Norway, because I had previously identified the ancestral source of that segment from the 1700s (click here to read about that). It took me a little over an an hour using Ancestry’s possible parent clues to build her a tree and find her descent from that family. It helped that I knew what I was looking for and only one of her Norwegian lines was from the Hordaland region.
23andme does not do tree matching for you like Ancestry does, but it does provide a chromosome browser. This means that sometimes you can tell from the segment that a cousin matches you on who the likely common ancestor is. When you keep a large master spreadsheet of all your matches from all the companies, this can sometimes be quick and easy (click here to read about using spreadsheets for DNA ).
There is a Valentine’s Day Sale at 23andme.com for American users, $20 off for up to two kits until Feb. 14 which brings down the price for the ancestry only version to $79, more in line with the other companies.
In other news, rumor has it that non-American users will finally be transitioned to the new experience in the next few months. If anyone from 23andme is at Rootstech this week, I will ask for more specifics on that.
Meanwhile there are several new features at 23andme for those of us, Americans, on the new experience:
- The automated triangulation feature now shows all DNA relatives, not just open sharers, and includes anonymous users with a link to request a share.
- Ancestry composition includes a timeline indicator making a guess as to when your ancestor with that ethnicity might have lived.
Click the read more for the details on these. I confess, I am at Rootstech right now, so not there is not much time to write about these in depth, just a few thoughts and images.
Did you know 23andme now provides the segment data for its ancestry composition assignments? This is a pretty recent feature and might even be useful. Unlike the other companies, 23andme does its admixture (aka ancestry composition) in chunks. This may make it more accurate than the others but in any case it means that they can give us the segment numbers. Then we can compare those to our matches.
To get these numbers, first pull down the reports menu and click on ancestry. On the initial ancestry page click on Ancestry Composition or the > symbol next to your highest group. Both are marked with my red arrow below.
The next page, the ancestry composition page has the pretty chromosome picture with ancestries displayed where you can change the confidence level from speculative (50%) to conservative (90%). To get a CSV file of the segments you click on Scientific Details at the top or the bottom of this page.
Then scroll all the way to bottom of that next page until you see this. You can select your confidence level as well for your downloaded data.
It is so delightful that you can now easily view your past correspondence with a 23andme match! To do this go to DNA relatives, which defaults to the People section, and click on the person. This takes you to a one-to-one comparison page partially shown below.
Your most recent message will appear in a box in the right hand column and you can scroll back in that box to see previous messages, both sent and received. Not all my oldest messages are there and I am not sure why. I did find one from 2012 and all the ones since 2014 seem to be available.
Past correspondence in the People view – as always, the red arrow has been added by me
I used to have to use the chrome add-on 23++ in order to search my inbox or outbox which took a long time with four years worth of messages to search. Sometimes it even crashed! This is much better.
More on the People view in DNA Relatives
Can’t find the person? You can use the search box on the right in the People view to find them, an improvement over the first roll-out of the new site. Note that the search in the DNA view works immediately as you type, no buttons to push, while the search in this People view requires you to press return. Annoying that they are different.
You can now download your aggregated results from the bottom of the People view page. Continue reading