A rare allele 22 at marker DYS518 was detected during a wider population study of Y-chromosome short tandem repeat (STR) loci. The novel variant was discovered using the YFilerÒ Plus PCR Amplification kit and the sequence of the new allele confirmed with Sanger sequencing. The allele range for marker DYS518 in the included ladder in the amplification kit falls between alleles 32 and 49 with a minimum allele size of 332 bp. Variants outside this range have already been discovered and their frequency is available in the worldwide Y-chromosome STR Haplotype Reference Database (YHRD) containing >250,000 STR haplo- types. Nonetheless, the rare allele described in this study has not been seen among the YHRD data set sam- ples, which has recorded alleles between 28 and 52.2, nor in other population studies published to date.