ok genetics experts, can you help decipher this report?

AHT4 KO
AHT5 MO

What test(s) did you order from them?

Ok, so I've figured out that the AME locus shows gender- so the tested horse is a male. But you probably already knew that. I'm interested to see what someone who has seen this type of report before can say about it

I had a chimerism test performed to see if his brindling was a result of embryo fusion...

The problem with that is the results are not always accurate. Chimerism is tricky.

When two genetically separate beings absorb together to become one creature, their DNA does not combine into one. The animal will have two different sets of DNA. You are not really able to do a test on blood or hair or any kind of body sample individually and get both sets of DNA. The two sets spread out to form the different parts of the body. Your horse's tail hair could all be from DNA1 and his lungs and kidneys could be the only parts of his body that DNA2 formed for all anybody knows. The only way to rule out chimerism is to get absolutely everything tested (blood, tissue samples from all organs, skin samples, hair samples from mane, tail, and various areas of the body).

To put this in perspective, I read an article somewhere that a family had a paternity test done on their child. The husband was the actual father of the child, but the DNA didn't match so the test showed that the husband wasn't the father. It turned out that the man had chimerism and his absorbed brother's DNA had developed to create the reproductive parts of his body.

Is this all they sent you? I would call the lab and ask for more explanation. They need to have an explanation for each abbreviation that they use.

Yah, that's all they sent, I thought they were sending me a paper copy of it too, but all I got was a pdf attachment to an e-mail. There was only this verbiage above the genetic markers:

"DNA types obtained from blood sample and individual hairs of different colors (2 white, 2 black) were identical and showed no evidence of chimerism. Brindling pattern cannot be explained by chimerism caused by embryo fusion."

So I am left with not knowing about what all the markers mean

I think I hear crickets :) I was hoping for tons of info from all the color experts out there, but ah well, I tried.

@ Reno Bay, thank you for youe great description of how it is very difficult to test for this. When I pulled his samples, I did pull some white hairs from his mane and some black hairs from his tail, along with a blood draw to try to gather as good of a chance as possible for it to show up. I don't want to keep testing any other areas of hair just for my knowledge...poor guy he would be bald if I tested as much as needs to :) Guess I will never know one way or the other.

No idea. My genetic test from UC Davis is clearly laid out with what is what.

Have you called the lab? I wonder if they meant to put in a key to their code.