Developmental validation of 15 X chromosomal short tandem repeat markers

The use of X chromosomal short tandem repeat (STR) markers has been greatly increasing in the forensic setting. Using guidelines set forth previously for the validation of autosomal and Y STRs, aspects of the feasibility of routine X chromosomal STR use were evaluated. Two mini-X chromosomal STR multiplexes capable of amplifying 15 total markers were developed and utilized to determine allele nomenclature, allele/genotype frequencies, mutation rates, and linkage between markers. Additionally, a concordance study between these multiplexes and a commercially available kit was performed. Here, the authors present an overview of this extensive developmental validation study.