Identification and molecular characterisation of an AMEL-X null allele due to an Alu insertion
The amelogenin locus is used in most forensic STR multiplex kits as sex-typing marker. In the present work, we performed the molecular characterisation of an AMEL-X null allele, observed in an Eritrean male profile when using either the PowerPlex® Fusion 6C or the AmpFLSTR™ NGM SElect™ multiplexes. After X-specific PCR amplification of the amelogenin locus using an in-house primer pair and Sanger sequencing, we found that the AMEL-X amplification failure was due to an insertion of a 370 bp Alu element. We recognised all the hallmarks of the Alu elements, i.e.