Dr. rer. nat Christoph Marschall, Dipl.-Biol. Christina Sofeso
DNA or genotyping using microsatellites (MS) is accepted globally as evidence in the area of forensics as well as in paternity testing. MS are noncoding DNA regions spread over the entire genome and consist of a varying number of repeats of a specific sequence motif. Every individual carries two copies (alleles) of these microsatellites in every nucleated cell. These copies may exhibit various lengths, depending on whether they were passed on by the mother or the father. The pattern of the different lengths of several microsatellites is unique in every human being (except in identical twins) and creates what is known as the genetic finger print. By analyzing several microsatellites at the same time, comparing the pattern of different individuals and by conducting approved procedures from the area of biostatistics, kinship can therefore be confirmed or ruled out with great accuracy.
Common questions include:
- Trio Test: Analysis of three individuals: both parents and one child; the analysis can provide reliable information on, for example, whether the potential father (putative father) is the biological father or not
- Deficiency Case: Analysis of two individuals: one parent and one child; the analysis can provide reliable information on kinship
- Twin Analysis: Analysis of twins of the same gender; the MS analysis can provide reliable information on whether the twins are identical or nonidentical
The accuracy of paternity testing depends on the number of tested individuals. According to the Gene Diagnostics Commission (Gendiagnostikkommission GEKO) of the Federal Government, inclusion of the mother in the testing should only be waived if she is not available. If no material of the mother is available in paternity testing, a prediction is still possible. However, extensive testing has to be carried out.