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