Flemish population data and sequence structure of the hypervariable tetranucleotide repeat locus D12S1090.

The allele frequency and sequence structure of the STR locus D12S1090 were investigated in 598 Flemish individuals. The locus shows a complex organisation with repetitions of GATA interrupted by TA and other tetra- and pentanucleotide blocks. No deviation from Hardy-Weinberg equilibrium was observed.

Variations in primer sequences are the origin of allele drop-out at loci D13S317 and CD4.

STRs have become almost the exclusive tool of genetic scientists in forensic typing work. Consequently, large numbers of samples are genotyped and the detection of rare abnormalities is to be expected. We found rare losses of alleles, also known as drop-out, at the two STR loci D13S317 and CD4.

Mutation of the repeat number of the HPRTB locus and structure of rare intermediate alleles.

During routine paternity testing a mutation of a paternal allele at the HPRTB locus was observed. The opportunity was taken to analyse this mutation at a molecular level. The repeat sequence is flanked by an imperfect repeat sequence and this region could be involved in the mutation mechanism.

Allele frequencies of nine STR systems in the Flemish population and application in parentage testing.

In order to apply a set of nine STR loci in parentage testing, we performed a population genetic study on a sample of the Flemish population. Genotypes for HUMHPRTB, HUMFABP, HUMCD4, HUMCSF1PO, HUMTH01, HUMPLA2A, HUMPLA2A1, HUMF13A01, HUMCYAR04 and HUMLIPOL were determined using three triplex PCR reactions and silver staining. Allele frequencies showed no deviation from Hardy-Weinberg equilibrium.