23andme Gives Me Only 85% Similarity In A Genome-Wide Comparison With My Daughter. Does It Mean That I Am Not Her Real Father?


#1

When my daughter took the 23andMe DNA test, I got to know that her genes are not completely similar to mine. Due to this reason, I am wondering If I am her biological father.


#2

I can understand why you are concerned after getting the results of the DNA test. After all, you imagine that there is a small possibility that you are not the biological father. However, it doesn’t mean you are not the real father of your daughter. When 23andMe checks your genes for similarity, they are only comparing a small percentage.
For example, if you were to take random pairings, the chances of them being similar ranges between 70% - 75%. The only time you will find 100% similarity is when they are clones. Another situation where you find such high similarity is when you have identical twins. When it comes to parents and children, the similarity hovers around 50%. When your wife got pregnant, she got the other X chromosome from you. Due to this reason, your daughter gets more of your genomes.
Also, it is standard to have more in common with your daughter, as she gets some of the DNA from your ancestors. If you go to the Advanced genome comparison, you can see which regions are half identical. By going through this data, you can see which chromosomes she got from both her parents. There may be cases where your daughter doesn’t get any genes from you, but your ancestors. You can identify these portions by looking for gaps in the diagram. For example, 23andMe uses green for your wife and light blue for your chromosomes. There will be sections where there isn’t any color in the diagram, which represents different genetic material.
You should know that recombination of chromosomes is random by nature. Due to this reason, it is quite possible for your daughter to not share any genetic material with you in certain chromosomes. However, this doesn’t disregard the fact that you are her father. Also, if you decide to have another child, you should test his/her DNA, as it will help you understand the data on these tests. You will find out that despite having the same parents, your daughter and newborn child don’t share the same genetic material.
Don’t feel bad for questioning the fact whether you are your daughter’s father. As there is no content about the true meaning of this percentage, it leaves room for misinterpretation. I would ask you to get in touch with 23andMe so that you can provide valuable feedback. For example, you can ask them to show some text for important facts and figures, so that their customers can understand the data properly.
I would like to add that the DNA test result doesn’t determine whether you are her father or not. Your selfless care and love are the two most important factors which make a father.