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Center for Health Sciences
Human Identity Testing Lab
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DNA Testing Information

Questioned Family Relationships DNA Testing
The laws of genetic inheritance proposed by Mendel used in association of DNA testing can often establish or refute questioned family relationships such as parent:child, sibling, grandparent, aunt/uncle, etc. The vast majority of questioned family relationships involve cases of questioned parentage and in such cases the lab is able to almost always produce a compelling result resolving the question either by excluding the alleged parent, or including him/her with high probability, i.e., >99%. The same result is generally possible when testing questioned grandparenthood. However, as the questioned relationship moves farther from parent to child, the likelihood of obtaining a compelling result decreases. Thus, sibship testing is less likely to produce a compelling result than is parent:child, or grandparent:child, and half-sibship is less likely to produce a compelling result than full sibship testing and so on.

In relationship cases either the relationship will be excluded, or, a likelihood ratio will be produced that is a numerical statement that reflects the weight of the evidence either for or against the claimed relationship. This ratio, also known as the relationship index, refers to the genetic odds in favor of the relationship. The size of this number is a reflection of how many elements of the DNA profile are shared between the individuals involved in the test, and how those shared elements are expected to be distributed within a family group or pedigree. In general, the more elements of the DNA profile that are shared provides a larger likelihood ratio. The likelihood ratio can also be expressed as a percentage probability. A larger likelihood ratio will produce a larger percentage probability that the questioned relationship is true.


  • DNA identity testing to determine if a parent could be the biological parent of a child or children in disputed parentage cases.
  • DNA identity testing to determine biological relationships between a child and a possible grandparent, aunt, uncle or other person for personal or legal reasons
  • DNA testing to determine if individuals are related as full siblings (same biological parents), half siblings (sharing a biological mother or father), or not likely to be related.
  • DNA testing to determine whether twins are identical or fraternal.
  • DNA testing for possible Native American tribal enrollment.
  • IMMIGRATION: We work closely with the USCIS and the U. S. Embassies and Consulates worldwide in order to provide DNA relationship testing for individuals and their families applying for immigrant visas.


  • Child support
  • Questions of inheritance
  • Custody determination
  • Proof of relatedness for immigration
  • Grandparent’s rights
  • Geneology verification

Forensic DNA Testing
The Human Identity Laboratory also offers forensic DNA typing and consultation to law enforcement and attorneys around the country. The lab is very experienced in obtaining DNA from forensic type evidence (body fluid stains, tissues including bone, and even touched items) and producing a DNA profile that is probative. In addition, we can provide consultation to law enforcement regarding work previously performed by a different DNA typing laboratory. We can also help with matters in which either the prosecution or defense requires consultation in preparing their case.
If you decide to have testing done, we will provide you with detailed descriptions of all these procedures if you so desire.