Long D13S317 variant allele: A cautionary case report

Exclusion at locus D13S317 between a father and child was observed in a kinship case, which at first glance appeared as a silent allele. However, a closer inspection using three commercial kits showed that the observed pattern is due to a long variant allele overlapping with different loci in different kits. Sequencing of the variant revealed a duplication within D13S317, that had also created an additional binding site for short amplicon reverse primer. If ignored, genotyping results including this variant may be wrongly interpreted.