[Genetic variation at STR-TH01 locus in the South Polish population]

We report on a rare allelic variant of the TH01 STR locus. Within this commonly used tetranucleotide repeat system, we identified and characterized by denaturating gel electrophoresis an allele of the size corresponding to 10.3 repeats, analogous to the most common 9.3 allele. The novel allele segregated from a putative father to the child in a paternity case. We discuss the advantage of high resolution second generation multiplex systems (SGM) using internal size standards during electrophoresis.