Different informativeness of the three hypervariable mitochondrial DNA regions in the population of Bologna (Italy)

Mitochondrial DNA (mtDNA) sequence variations at hypervariable regions HVI, HVII and HVIII were analysed in 100 unrelated Italians from Bologna. The values of the statistical parameters are in agreement with the range of European populations. We suggest that the less informative HVIII region may be useful to distinguish HVI-HVII identical sequences in forensic analysis especially when nuclear DNA cannot be investigated.     

Automated fluorescence analysis of CAG repeats at the human androgen receptor gene (HUMARA): evaluation of polymorphism in an Italian sample and report of a new allele.

The HUMARA CAG repeats polymorphism was studied in an Italian population sample. Polymerase chain reaction amplification and automated fluorescent analysis were used. A total of 19 and 15 repeats was observed in female and male subjects, respectively, and one new allele was found. The authors conclude that this X-linked short tandem repeat, typed without ambiguity and with a heterozygosity of 0.902, is useful in parentage testing of female subjects.     

Myotonic dystrophy CTG repeats in an Italian population sample: evaluation of the polymorphism for forensic applications

The myotonic dystrophy (DM) CTG repeat polymorphism has been studied in an Italian population sample. Polymerase chain reaction (PCR) amplification, manual polyacrylamide gel electrophoresis (PAGE), and silver staining were employed. Alleles were typed by comparison with a sequenced allelic ladder. A total of 25 different alleles, spanning the range from 5 to 31 CTG triplets, was observed. The heterozygosity was 79%, and no significant deviation from Hardy-Weinberg equilibrium was found. Eighty-one meioses from parentage testing were also analyzed, and a Mendelian pattern of inheritance was observed in all cases. In addition, we could successfully type the DM locus in 20 laboratory-prepared bloodstains, with 1 ng of DNA allowing clear definition of alleles. We conclude that the CTG repeats at the DM locus may be useful for forensic applications.