A siblingship test is useful for determining if individuals are full brother/sisters, half brother/sisters or unrelated. Whenever the mother(s) is/are known, it is strongly recommended that they be included in the test. Including the mother(s) in the test can increase the combined likelihood ratio ten-fold, where you might see a probability of 99.999% instead of only 83.9%.
Listed below are a couple different scenarios incase you might be a little confused about which test to request:
Scenario one: FULL vs. HALF
If two children know they have the same mother and want to know if they have the same the same father, or they know they have the same father and want to know if they have the same mother, you would request FULL SIBLINGS vs. HALF SIBLINGS.
Scenario two: FULL vs. UNRELATED
If two children are unsure if they have the same mother and the same father and it’s possible they share neither, you would need to be tested as FULL vs. UNRELATED.
Scenario Three: HALF vs. UNRELATED
If two children have a different mother and want to know if they have the same father or, they know they have different fathers and want to know if they have the same mother, they would need to be tested as HALF vs. UNRELATED.
Due to the complex nature of this type of relationship testing it’s best to speak with one of our case coordinators to make sure you get the right test for your situation.