If potential fathers are closely related in a paternity test case, for example if the alleged fathers are brothers or are father and son, then a sample will be required from all potential fathers. If this advice is not followed, it may only be possible to exclude a person as the biological father.
An inclusion in this type of paternity test case may be dependent on ruling out the second related party due to the fact that close relatives have more DNA in common than unrelated individuals.
If alleged fathers are related but not all potential fathers are available to take part in the paternity test, then in order to get a conclusive answer, the paternity test will need to be carried out as a complex paternity case. Complex tests look at up to 46 genetic markers in order to make a judgment on the samples collected. If potential fathers are related, please be sure to speak to an advisor about your paternity test. Peace of mind complex tests can be carried out using the home DNA testing kit, however, legal DNA tests must be carried out at one of our DNA testing clinics.