Siblingship Testing

A sibling test can confirm if two individuals are likely to be full or half siblings. It’s impossible to determine with 100% certainty if two individuals are siblings without having either one or both of the parents’ participation. Nevertheless, DNA tests help determine if two individuals are likely to be related.

Siblingship testing can be requested by a parent or the siblings themselves (if they’re over age 18 or a legal guardian is providing permission for their involvement).

A DNA sample from parents isn’t required to successfully perform a sibling test, but if you have a parent willing and ready to deliver a sample, it will produce more precise results. If a mother is unable to participate in the DNA test, a grandparentage test might be more definitive.

This is the way it works in all relationship DNA tests – the more people willing and ready to be tested, the merrier (and improved, accurate test results)!

What kinds of siblingship DNA tests can we perform?

Here at Test Smartly Labs, we can test for:

  • Complete siblingship – in the case where you and your sibling understand you share the same mother but want to check if you share the same father who is unable to get tested. We could even run this test if the mother is not able to participate, although her involvement will significantly increase the validity of the test.
  • Half siblingship – if you and someone else know you have different mothers but want to determine whether you share the same father who is not available to be tested. If one or both moms will participate in the test, the results will be conclusive; however, parental participation isn’t required.

After all samples are collected, results are usually available within 5-6 days.

Siblingship testing: How it works

As an individual, 50 percent of your genes originated from your mother and 50% from your father. If you’ve got a full sibling, they also received 50% from mom and 50% from dad.

But, unless you’re twins, you do not look alike! That is because genes express themselves differently in people.

Let’s pretend a receptor is like a dice. It’s one block with six different sides (in genetics, this is called an allele.)

(Notice: genes don’t necessarily have 6 variations. Some have more, and some have less. This is merely an example)

When a child is conceived, it’s equivalent to the mother and father rolling the dice. For you, say the dice landed to a two and that is why you’ve got brownish hair… but for the sibling, it landed on a four, and that’s why they have red hair.

Although you and your sibling have genes expressing themselves in unique ways (one showing a two and the other a four) – you obtained the same set of genes (the same dice were rolled) from the same two individuals, and DNA testing can verify that.

In the case of a half sibling, you won’t have as many genes in common; however, DNA tests can determine whether there are sufficient fitting genes to prove you share a biological mother or father.

Test Smartly Labs can work with any family situation to help get siblings examined. To get started, contact us today.