Services - Family Studies

Family Studies

The technology used for DNA testing can often be applied to special applications called
Family Studies. In these situations, rather than answering the question "Is this man the
father of the child?" different or more involved questions can be assessed, testing the
likelihood of other biological family relationships. The same genetic markers that are used in
standard paternity tests are used to determine paternity when the alleged father is
deceased or unavailable for testing (using grandparentage testing), to assess whether
other people are biologically related such as possible brothers (siblingship, or sibship
studies), and even whether twins are genetically identical (twin studies). In Estate
settlements, establishing or proving such family relationships can provide important
information.

Grandparentage Testing
In cases where there is a question about a biological relationship between a child and a
possible grandparent, the Identity Test should include samples from the child, the mother
and both parents of the alleged father. Such a test is used when the alleged father is
deceased or unavailable for testing.

Similarly, a family study involving aunts, uncles or other related parties can often be used
to conclusively establish a relationship - for either legal or personal purposes.

Siblingship or "Sibship" Testing
A DNA Identity Test designed to determine whether two people have biological parents in
common is known as a "siblingship study" or "siblingship test." Individuals are full siblings
when they have the same biological parents, or half siblings when they share one biological
parent, either a mother or a father.

Twin Studies
Fraternal (dizygotic) twins are formed from two eggs, fertilized separately, which can result
in two siblings of the same or opposite sexes. The hair and eye color, as well as many of
the other characteristics of fraternal twins, can vary widely -- and fraternal twins can
actually be half-siblings, with different fathers. The fact that such genetic differences exist
can be confirmed by DNA testing.

In contrast, identical (monozygotic) twins occur when a single fertilized egg splits after
conception into two identical halves, each of which develops separately. Each identical twin
will have exactly the same DNA, a fact that can be established through testing. Of course,
identical twins are of the same sex and have the same eye and hair color, as well as blood
type. Only one of every three sets of twins is identical.