A DNA test can be performed when you suspect whether you share the same parent with your brothers and sisters and it is helpful when the concerned father or mother is deceased, unwilling, or not available to participate in the testing. When you suspect you share the same biological parent as that of your brothers and sisters, a sibling DNA test can be done to determine the likelihood.

PaternityUSA offers the best sibling DNA test that is easy to use and also includes detailed instructions. Place the order online and the kit will be delivered to you by mail. The kit contains buccal swabs for each person. You will have to collect the samples by just rubbing the oral swab on the inside of the cheek. They offer free two-way shipping that helps you return your DNA samples to their laboratory free of cost. They assure you results as accurately as possible.

Types

When you and your siblings have the same biological parents, it is called full siblings in which you share 50% of genes due to common inheritance. On the other hand, when you share either of the parents in common, it is called half-siblings and you will share only 25% of genes.  Here are three different types of DNA sibling tests.

Full Siblings Vs Unrelated

This type of siblingship DNA test is requested in US immigration while applying for an immigrant visa. In this test DNA of two different individuals is compared to prove whether they have the same biological parents or are completely unrelated.

Full Siblings Vs Half Siblings

This DNA test with siblings who have the same biological mother to determine whether they have the same biological father. For this test, the sample from the biological mother is also recommended that helps determine exactly, which genes are inherited from the biological father. This also helps increase the conclusiveness of the results.

Half Siblings Vs Unrelated

This test is done to determine whether two individuals having different biological mothers have the same biological father. Including the samples from one or both biological mothers greatly increase the conclusiveness of the test.

Are The Results Conclusive?

DNA test for siblings is not as conclusive as paternity testing since the DNA of siblings will not match each other except for identical twins. This is because a parent could pass on only one of two alleles (an alternating form of DNA) to their offspring. So, when one child gets one allele from their parent, the child’s sibling inherits the other allele. Hence, the analysis is done based on probability. So, it is not possible to obtain a conclusive result in a sibling DNA test.

The test results are expressed in a percentage where more than 90% probability is considered the existence of a relationship and less than 15% is considered as no relationship exist. You must remember that in some cases, including undisputed relatives of the alleged parent in the test may be advantageous to get more conclusive results.

Cost

A sibling DNA test requires more extensive analysis hence costs more than a paternity test. The cost of this test may range from $100 to $20000 depending on the complexity and nature of the test.