Rapid analysis for confirmation of amelogenin negative males characterized by aYp11.2 deletion

In humans, the amelogenin gene is present on both the X and the Y chromosomes: there are size differences in this gene between these chromosomes, which have been utilised for sexing in forensic casework and prenatal diagnosis. The assay typically generates a 106 bp long fragment from the X chromosome and a 112 bp long fragment from the Y hromosome. Several studies have shown that the amelogenin gender test may not always be concordant with true male gender. Deletions of AMELY can result in no amplification product and these null AMELY alleles can occur in different percentages in different population groups. The literature data support that the null allele is the result of a larger deletion on the short arm of the Y chromosome. Considering the consequences of the result obtained using only the amelogenin marker, and potential interpretation difficulties in the few cases where gender misinterpretation may be problematic, in this paper we propose a method for the identification of samples with deleted AMEL based on a small polyacrylamide-gel electrophoresis of a duplex PCR product of a novel marker residing in the SRY gene, which results in a 197 bp long PCR product in combination with primers for AMEL. This method can be applied, as an additional assay, in case of doubt regarding the presence of deleted AME in the DNA profile.