Y Chromosome analysis is not useful..........

During Y-STR analyses, genetic abnormalities—such as duplications or deletions—can complicate data interpretation. It is important to keep in mind the possibility of rearrangements involving Y-STRs used in forensic investigations, especially when more than one peak is present in a Y single-copy locus. In fact these alterations could address to a wrong mixed (originated from two or more individuals) DNA profile interpretation. In a routine paternity testing, it was found that a father/son pair with double peaks at two loci. Both these markers are included in a commercially available kit used in forensic genetics. One locus is also included in  SWGDAM-recommended Y-STR panel. Moreover, since both these markers map in AZFa region, samples were analyzed to clarify a possible relationship between this Y-STR profile and infertility. For the same reason, two half-brothers involved in a deficiency paternity testing with null allele at DYS448  locus, were analyzed for AZFc region deletions. Since DYS448 null types were already described, these samples were compared with the literature data. A null Y-STR locus should not
represent a problemfor profile interpretation,more than one peak at one or more loci could lead up to a  deep misinterpreting of a profile and therefore from which kind of sample the profile come out