[DNA analyses in forensic investigations]

Variable number of tandem repeat (VNTR) polymorphisms are used as genetic markers in paternity testing and forensic investigation. The blot patterns obtained with single locus probes are easily interpreted, and the fragment sizes can be calculated for further statistical evaluation. Fragments cleaved with Hinf I and analysed with the probe YNH 24 were found to vary in estimated size within +/- 1.5 per cent of the number of base pairs. In paternity testing, a window of +2.5 per cent will yield a risk of false exclusion of less than 1 in 10(6), with an estimated exclusion rate of about 90 per cent. In paternity testing, electrophoresis of mixed DNA samples from the child and the suspected father yields significant information irrespective of exclusion. The mean calculated paternity index for non-excluded men obtained with the YNH 24 probe was 8.4 (range, 2.6-19.2).