| Sibling DNA testing is designed to determine sibling | | | | siblings. For instance, a DNA index of less than |
| genetic relationships. Such tests establish the | | | | 1.00 indicates non-relatedness, whereas a DNA |
| statistical probability of whether the siblings share | | | | index of greater than 1.00 indicates that the two |
| the same two parents. A DNA sibling test can be | | | | tested individuals are more likely to be true |
| performed to analyze the relationship of biological | | | | biological siblings. |
| siblings by collecting samples from both siblings; | | | | A half-sibling DNA index can also be obtained to |
| however, including one common parent increases | | | | determine whether the siblings share only one |
| the accuracy of this type of analysis, and is highly | | | | common parent, versus two common parents. |
| recommended. | | | | The ratio of the half DNA index versus the full |
| While conducting sibling DNA testing, the DNA | | | | DNA index establishes whether the two individuals |
| laboratory determines the genetic profile of the | | | | share one parent or two parents. DNA testing can |
| alleged siblings and, based on the type of genetic | | | | also help determine if twin siblings are fraternal or |
| material inherited by each sibling, a DNA index is | | | | identical. For instance, if the DNA profiles of the |
| determined. Based on the results of the DNA | | | | twins are different then the siblings are considered |
| index, the sibling relationship is established and a | | | | fraternal; however, if the profiles are identical then |
| higher value DNA index indicates a greater | | | | a probability of being identical twins is calculated. |
| likelihood that the two individuals are true biological | | | | |