How likely is it to get a conclusive result?

Type of TestParticipantsLikelihood of Conclusive Result
Paternity or MaternityTwo Parents and Child99.99%
One Parent and Child99.9%
Sibling Half vs FullSiblings and Mother96%
Siblings78%
Sibling Half vs UnrelatedSiblings and Two Mothers94%
Siblings and One Mother86%
Siblings73%
GrandparentageTwo Grandparents, Grandchild and Mother99.9%
Two Grandparents and Grandchild99.2%
One Grandparent and Grandchild73%
AvuncularAunt or Uncle and Niece or Nephew73%

Why is my result inconclusive?

An inconclusive result is received when we are unable to confidently draw a conclusion from the similarities between the samples we have received. These inconsistencies occur as there are genes within the population that can be shared without being related. Another change can come from mutations in a donor’s genome which mean they no longer match. By testing 23 unique genes, we lower the risk of an inconclusive result.

As a UKAS accredited and Ministry of Justice approved laboratory we are unable to provide speculation on results and have a legally binding criteria on when to report a result as conclusive.

For non-parentage relationships a result of less than 10 % comes back as the less related relationship and more than 90% comes back as the most related relationship.

For paternity/maternity test it is less common to get an inconclusive result and will only be inconclusive if the percentage probability is between 0.02% and 99.98%.

What does % probability mean?

The % probability comes from statistical analysis of each participants DNA, taking into account how common each donors genotypes are in the general population, so we know they are definitely shared due to being related as opposed to by chance.

What can I do if my result is inconclusive?

Include a mother, increases likelihood of a conclusive result as we can remove some of the DNA being compared, which improved the statistical analysis

Test a different relationship. We are able to extend the test against 1st degree relations (Grandparents, Aunts/Uncles). If you are testing sibling, try both siblings against a potential father.