What is a Paternity Index?
• Can I cheat DNA Paternity testing? • Is it mandatory to get samples from mother? • What is the difference between a blood DNA test and a mouth swab DNA test? • Can hair samples be used for DNA paternity testing? • How old does the child need to be for paternity determination testing? • What if the two possible fathers are related? • What is the best sample to take from a dead body for DNA testing? • Can the presence of blood or semen be detected on an item of clothing or other materials/objects? Can it be used as a test sample? • I have a sample with a male/female mixture, but no male DNA profile was obtained from standard testing. Is there a way to obtain a male profile? • I have black hair and brown eyes. How can I have a baby with blonde hair and blue eyes? • Can a DNA test show whether twins are fraternal or identical? • Can a DNA test help me identify biological relatives? • Is there a difference in the accuracy if blood is not used? • What is the basis for population statistics
The Paternity Index or PI gives the odds that the alleged father with a matching allele is the biological father of the tested child. The frequency of each DNA segment (allele) in the human population varies depending on the size of the allele and the race of the alleged father. The prevalence of allele sizes differs from race to race which makes knowing the race of the alleged father important for statistical analysis. Databases are available for Caucasian, Black, Hispanic, and Asian races. If the race is not certain, lowest PI of all available races is used. This is a conservative approach for calculating the probability of paternity (POP). The frequency of an allele is determined by how many individuals in that database have an allele size, divided by the total number of individuals in the database. The result frequency is used to calculate the PI.
