Domenico De Leo

Y-chromosomal STR haplotypes in a Northeast Italian population sample using 17plex loci PCR assay

One hundred fifty-five unrelated, autochthonous healthy males from Northeast Italy were typed for the 17 Y-chromosome short tandem repeat (STR) (Y-STR) loci DYS456, DYS389I, DYS390, DYS389II, DYS458, DYS19, DYS385, DYS393, DYS391, DYS439, DYS635, DYS392, Y GATA H4, DYS437, DYS438, DYS448 using the AmpFLSTR Yfiler polymerase chain reaction amplification kit. A total of 153 different haplotypes were observed, and among these, 151 were unique, while 2 were found two times. The overall haplotype diversity was 0.9997. Furthermore, 50 father–son pairs, previously confirmed by autosomal STR analysis, were typed using the same set of 17 Y-STR loci, and, among 850 allele transfers, three mutation events were identified, giving an average mutation rate of 3.53×10−3 per locus per generation (95% confidence interval 0.73–1.03).

Development and forensic validation of a new multiplex PCR assay with 12 X-Chromosomal short tandem repeats

One multiplex system for the co-amplification of 12 X-chromosomal short tandem repeats (STRs) DXS7132, DXS8378, DXS6809, DXS7133, DXS6789, DXS7424, GATA172D05, HPRTB, DXS7423, GATA31E08, DXS101, DXS6807 and amelogenin was analysed in a sample of 200 (100 males and 100 females) unrelated healthy individuals living in Northern Italy. The chi2-test for genotype distribution of the X-chromosomal STRs showed no significant deviation from the Hardy-Weinberg equilibrium (HWE). Allele frequencies between female and male samples were not significantly different in all examined markers. In the kinship cases involving 40 family trios with daughter and 10 father/daughter duos, no mutation was detected. The combined power of discrimination (PDc) of the 12 X-STRs for both females and males was PDc > 0.999999.

Two additional reports of deletion on the short arm of the Y chromosome

Deletions on the short arm of the Y chromosome involving the amelogenin Y gene (AMELY), located on Yp11.2, can be misleading for sex typing with serious consequences in forensic applications and prenatal diagnosis. In this study, we describe two AMELY null cases concerning two unrelated Italian males from Northeast Italy. PCR amplification of short tandem repeats on the Y chromosome (Y-STRs) showed a lack of AMELY and DYS458 markers. The presence of all the other markers located on the Y chromosome and of the SRY gene in both samples led us to conclude that a deletion had occurred in a portion of the short arm of the Y chromosome. Twenty-three Y-specific sequence tagged sites (STSs) were chosen to delineate the deletions length, which was estimated to be in the range of 3.35-3.87Mb for one sample and 1.51-2.58Mb for the other. These and previous findings suggest that in all cases where potential AMELY drop out has occurred, it should be used additional specific Y chromosome markers or human DNA quantification methods that specifically quantify male DNA using target male genomic markers, which not being located within the deletion regions, allow an accurate sex identification.

Evaluation of genetic parameters of 22 autosomal STR loci (PowerPlex® Fusion System) in a population sample from Northern Italy

The PowerPlex® Fusion System (Promega, Madison, WI) is a short tandem repeat (STR) multiplex that allows co-amplification of 22 autosomal STRs, including the CODIS core and the European Standard Set loci, plus amelogenin for gender determination and DYS391 male specific marker included in order to avoid errors in gender assignment when null Y-alleles or deletions of the Y-chromosome short arm involve the amelogenin locus. Allele frequencies and forensic efficiency parameters were estimated in a population sample of 303 unrelated healthy individuals living in Northern Italy. No significant deviations from Hardy–Weinberg expectations were observed after applying Bonferroni’s correction for multiple testing. The combined power of discrimination was 0.999999999999 and the combined power of exclusion was 0.9999956. A rare 28 allele at locus D12S391 was observed, while one tri-allelic pattern at Penta E locus was detected. Population differentiation test revealed significant genetic diversity between our population sample and other European populations considered. The results showed that the PowerPlex® Fusion System is one of the most informative kit available in forensic genetics and may prove useful in both human identification and kinship analysis.

Effects of individual dental factors on genomic DNA analysis.

The use in forensic medicine of methods pertaining to molecular biology has made it possible to identify human remains through the analysis of polymorphic profiles of human DNA. Voluntary, accidental, or natural postmortem degradation, as well as environmental conditions, influences the preservation state of the corpse, making it sometimes difficult to obtain biologic material suitable for genetic analysis (e.g., hair, soft and/or hard tissue). According to their anatomic/morphologic characteristics, dental formations are particularly resistant to external insults and are thus suitable for this kind of research. The purpose of this work, conducted on nonselected dental findings (presenting intrinsic characteristics similar to those usually found in forensic cases) that were homogeneous with regard to environmental factors, was to determine an operative protocol that will enable combination of the maximum availability of genomic DNA with the preservation of the morphologic characteristics of the tooth for classic anthropologic evaluations.

Medico-legal considerations in a case of splenic injury that occurred during colonoscopy

Colonoscopy has became the gold standard diagnostic and therapeutic treatment for rectum and colon diseases. The splenic injury is a rare complication of colonoscopy and relatively few cases (less than 70) have been reported in the literature so far. Here we present a case of splenic rupture identified in an 80 year-old man few hours after an apparently uneventful colonoscopy. Acknowledging a causal relationship between the lesion and the diagnostic procedures, we discuss the possible medico-legal implications with regard to professional liability considering the exceptional nature of such an event and the stance recently taken by the Italian law.

Italian population data for D1S1656, D3S1358, D8S1132, D10S2325, VWA, FES/FPS, and F13A01

Allele frequencies for seven STRs loci were obtained from a sample of 215 unrelated healthy Italian individuals.

Lethal Effect of a Single Dose of Rasburicase in a Preterm Newborn Infant

This case report describes a preterm newborn infant who was treated with a single dose of rasburicase for an increase in uric acid level. He died on the third day as a result of complications of hemolysis, which appeared to be precipitated by rasburicase. The patient’s death was preceded by progressive respiratory insufficiency, lactic acidosis, and hyperbilirubinemia, culminating in refractory hypoxia and hypotension. A postmortem assay for glucose-6-phosphate dehydrogenase showed deficiency and the glucose-6-phosphate dehydrogenase Mediterranean genotype.

Are rapidly mutating Y‐short tandem repeats useful to resolve a lineage? Expanding mutability data on distant male relationships

Y‐chromosomal short tandem repeats (Y‐STRs) are essential to relate male lineages in forensic and evolutionary studies. Although large panels of Y‐STR markers are now available, none possess sufficient discrimination power to distinguish close male relatives. This limit may be overcome by the use of rapidly mutating Y‐STRs (RM Y‐STRs), characterized by mutation rates higher than common Y‐STRs. Recently, multicenter studies evaluated the ability of RM Y‐STRs to differentiate father–son pairs; however, more extensive data on distantly related males are needed.

Kinship analysis: assessment of related vs unrelated based on defined pedigrees.

The study aimed at evaluating whether the adoption of enlarged batteries of STR markers in kinship analysis may provide LR values suitable for discrimination of relatives from non-relatives, in comparison to conventionally used STR panels. The presence of LD among some loci and its effects on LR values were also assessed. Three hundred pairs of related and unrelated individuals, each separated from 1–3 generations and residing in North Italy were genotyped with the Investigator HDplex STR kit (Qiagen), AmpFlSTR Identifiler (Applied Biosystems), and PowerPlex Fusion System (Promega). Loci and alleles shared between each pair and within groups of relatives were compared. Also, combined LR values with and without loci in LD, sensitivity and specificity were calculated for each commercial kit and their combinations. Full siblings displayed the largest number of shared loci and alleles, with a proportion of LR ≥ 10 results significantly higher than other degrees of relatedness and, consequently, with the lowest percentage of inconclusive and false negative results. Only minor differences were detected in the combined LR distributions, after including or omitting loci in LD. However, these became only appreciable when analyzing more distant relative pairs.The implementation of additional STRs into the LR calculation allowed a complete and robust discrimination between relatives and non-relatives only for full siblings, by removing the typical uncertainty of the “grey zone”, while this was not achieved among other degrees of relatedness. Furthermore, the presence of loci in LD seems to not significantly affect LR distributions within each generation.