Sibling DNA Testing

Validity Genetics offers quick and convenient DNA testing for siblings and twins in the comfort of your own home.

Have you ever wondered if your brother or sister is actually related to you? 

Does your child share similar features and genetic traits with their sibling, but you have doubts about whether they share one or both parents? 

Are you a twin that wants to find out if you are fraternal or identical? 

A DNA test can give you the answers you seek!

Get Your Test Results in Three Easy Steps!

  • Step 1: Order Your Sibling DNA test!

Order your DNA test like you would any other product online.  Fill in your name, email, shipping address, and purchase with a Visa, MasterCard or any Credit card you wish to use.  Your paternity test will be mailed to you in a nondescript package to ensure your privacy.

  • Step 2: Follow the Simple Directions at Home!

The easy to use kit will contain everything you need and the enclosed directions will walk you through the quick and simple DNA collection process.  Make sure to fill in the paperwork in full, sign the consent form, and label as directed.

  • Step 3: Return the Prepaid Envelope to Our Laboratory!

It's as easy as that!  Once we receive your test kit we will have your Sibling DNA test results ready and emailed to you in about 48 hours!

How is this test Determined?

The sibling DNA test uses statistical analysis to compare the DNA of siblings. This determine if alleged siblings share both parents, one parent, or no parent at all. 

DNA tests for siblings can have three possible conclusions: 

  • Full Sibling 
  • Half-sibling 
  • Unrelated

Sibling-ship DNA testing is analyzed through probability, which may lie in between 0% to 99.99%. 

Higher percentages of about 50% indicate a full sibling (i.e. they share both parents). Probability percentages of about 25% indicate half siblings (i.e. they share a single parent) and lower percentages indicate that the individuals are unrelated.

The results for sibling-ship can be made more accurate by including a common parent in the testing procedure. The reason for this is because the DNA shared by siblings is comparatively lower than the amount shared with parents.

Involving either or both alleged parents in the testing procedure can guarantee the results with better confidence. 

Full siblings vs. half siblings

This DNA test determines the probability that two individuals who have the same biological mother also have the same biological father. 

This DNA test analysis can also determine the probability that two individuals sharing the same biological father have the same or different biological mothers, and vice versa. 

For increased accuracy of this test, it’s recommended that at least one parent is also tested. This greatly improves the conclusions of the test. 

Full or half siblings vs. unrelated

This DNA analysis determines the likelihood of whether the two individuals tested may have the same mother and/or father, as opposed to being completely unrelated. 

For greater accuracy of the test, we recommend samples from one, or preferably all, of the alleged, biological mothers and fathers. 

Please note that a sibingship test may not always be as conclusive because the inheritance pattern and genetic markers vary between offspring even if they have same parent(s). This is because the inheritance pattern and genetic markers vary between offspring more than they do between a parent and child. 

Home Sibling DNA Test


Twin Zygosity Testing

What is a twin zygosity DNA test?

1 in every 60 births involves the birth of a twin. Therefore, twin DNA testing has become very popular. 

Generally, 30% of twin births are monozygotic twins (identical), while 70% are dizygotic twins (fraternal). However, the only accurate way to find out whether the twins are monozygotic or dizygotic is to conduct a twin zygosity DNA test.

About monozygotic (identical) twins

Monozygotic or identical twins develop from a single fertilized egg known as a zygote. 

In instances of monozygotic pregnancies, the zygote splits up during the early developmental stage to form two embryos – resulting in identical twins. 

Because the identical twins come from a single egg and sperm, their DNA is exactly the same which makes an identical twin relationship easy to test!

About dizygotic (fraternal) twins

Dizygotic or fraternal twins develop from two different eggs in the mother’s womb, which are fertilized by two different sperm. 

Fraternal twins have DNA similar to full siblings. 

Home Twin DNA Test



DNA test results in as little as two days!