When do I need a siblings DNA test?

A siblings test is recommended if it not possible to carry out a home paternity test or maternity DNA test. Essentially, in this test, we try to establish whether tested individuals are biologically related to a parent without actually testing that parent. A sibling test will confirm whether you and your sibling/s are full, half or not related at all by comparing the siblingship index using highly sophisticated techniques in molecular biology.

Our test begins from $589 with results available in 7-10 working days. Return to our relationship DNA testing page if you want to read further or select one of the below options.

What makes us full brothers and sisters?

Each of us inherits 50% of our DNA from our mother and the other 50% from our father. Full brothers and sisters share both biological parents which means they will share (through genetic inheritance) more DNA than half brothers and sisters. In fact if brothers and sisters are full siblings they will share 50% of their DNA vs 25% if they are half. Half brothers and sisters will share only one biological parent which means they will share far less common DNA.

We strongly suggest including the sample of a known mother to provide stronger results. This is because if we have her sample we can eliminate her share of genetic inheritance in the DNA of the sibling/s and work solely with the DNA inherited from the father.

What information will we require?

The following information is routinely asked to clients to assess which DNA test is most suited.

  • Who is available for the test
  • What is it you exactly want to establish?
  • What is the sex of the test participants
  • Do the parties live in different places

Sample collection for the test

homeDNAdirect Australia has made sample collection a walk in the park thanks to our easy-to-use home sample collection kit. You will receive our kit by regular mail once you have placed your order and inside it you will find:

  1. Mouth swabs for collecting DNA
  2. Instructions
  3. Sample submission forms
  4. Self-addressed envelope

Siblings DNA test in cases of same sex siblings

The following are all tests that can be carried out between siblings. Please read through them and contact us for any assistance.

  • Males wishing to know if they have the same father can do a Y chromosome test.
  • Females that want to determine whether they have the same father can do X chromosome test.
  • Individuals can establish if they share the same maternal line by doing an MtDNA test.