When one of the parents is not available for testing, it may be
beneficial to have a sibship DNA test performed. A comparison can be made
between the two siblings without additional family members,
although, adding the common parent will help clarify the comparison.
Sharing DNA
Two full siblings
will share half of there DNA in common. Each received half of their
DNA from mom and half from dad, but the half each parent donates
will change with each child (with the exception being identical
twins). For this reason, two full siblings do not have to share a
number (allele) in common at each genetic location, like a father
and child would. (see
science of paternity)
All about
Likelihood
Because siblings
don't have to share alleles in common at each location, the best
possible information that can come from a sibling comparison is how
likely the two individuals are full vs. half vs. unrelated. In most
cases, the two siblings know that they share the same mother and
want to know if they share the same father. If the father is still
alive and a sample can be obtained, it is strongly recommended that
a sample be collected from him for comparison to the two siblings.
$149 Sibling
Test (Mother & 2 Sibs, Best
Results)
