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Suicide is a very serious act and risk factors have been classified as psychiatric, environmental or biological. It has been suggested that CYP2D6 gene involvement in the impact on suicidality may be due to unsuccessfully outcome of antidepressant therapy in ultrarapid metabolizers. An alternative explanation is based on CYP2D6 role in the metabolism of endogenous brain substrates which could affect psychological functioning (personality, cognitive functions and vulnerability to psycopathology). Actually, previous studies showed a high frequency of CYP2D6 duplication/multiduplication among suicide cases and attempters. The present preliminary study investigates CYP2D6 polymorphism in autopsy samples from suicide cases evaluating the enzymatic activity based on the number of active alleles. Blood or buccal swabs from suicide cases (33 out of 57) were analyzed. Whole CYP2D6 gene has been amplified by long-PCR, and 11 relevant single nucleotide polymorphisms (SNPs) were detected by minisequencing in order to identify the most common alleles showing different enzymatic activity. Samples were separated on an ABI 310 Genetic Analyzer and quantitative information derived from electropherograms was employed to establish the phase of gene duplication in heterozygous individuals. Phenotypes were predicted according to the number of active alleles and individuals were grouped in four enzymatic activity classes. Results were compared with published data using Fisher's Exact test performed by RXC software. p-Values double left arrow 0.05 were regarded as significant. Our preliminary results are in agreement with previously published data showing a higher proportion of individuals carrying more than two active CYP2D6 genes among suicide death cases compared with natural death cases. Despite the limited number of tested individuals in our preliminary study, also due to the DNA quality in forensic samples, the higher number of ultrarapid metabolizers in suicide cases seems to confirm an association between CYP2D6 genetic polymorphism and suicide. Further studies increasing the suicidal sample are needed to verify the data and to look for an explanation.

In this study we screened 48 gastrointestinal carcinomas, 13 urogenital and 7 oral carcinomas in parallel with control samples for the 15 STR loci of the AmpFlSTR Identifiler Kit to provide further data useful to evaluate the applicability on cancerous tissues of STRs used in forensic field. A total of 37 cancerous tissues (54.4%) showed allelic alterations when compared with the corresponding normal tissues: 29 (78.4%) gastrointestinal tumors, 4 (10.8%) urogenital tumors and 4 (10.8%) oral tumors. The loci most frequently affected by allelic alterations were VWA, FGA and D18S51. These results suggest that great care should be taken in the evaluation of the DNA typing results obtained from clinical cancerous specimens when no other reference samples containing normal tissue are available.

We have studied the distribution of Y chromosomal haplotypes and haplogroups in two population samples from the Romagna region (North Italy) by analyzing male-specific markers that reflect past and recent history: SNPs and STRs. The population samples were collected in the urban area of Rimini, an ancient port in Roman age and in the near rural area of Valmarecchia, that is more isolated and geographically out of ancient trading ways. We analyzed 11 Y STRs by a commercial kit and 20 binary polymorphisms by minisequencing analysis. In spite of the different historical records and geographic locations, the two population samples showed high genetic affinities likely due to modern demographic migrations that might have eroded the past genetic substructure.

A novel reproducible strategy to type the ABO blood group system by the minisequencing of five nucleotide positions using SNaPshot (Applied Biosystem, USA) is described. This new technique has been successfully applied on 30 blood donors and the results agree with the known serologically based predicted genotypes. (C) 2003 Elsevier B.V. All rights reserved.

Requests for solving complex kinship casework involving at least one female are increasing and in these circumstances the analysis of X-chromosomal STR markers plays a relevant role. Actually, it is well known the superior statistical power of X-STRs compared to autosomal markers in solving relationship when two sisters or half-sisters are involved and none of parents is available, in maternity testing or in cases involving close relatives as alternative putative fathers. In addition, the possibility to amplify more loci simultaneously and the strategy based on the analysis of four linkage groups to obtain the X-haplotype provide a powerful and validated tool. Nevertheless, haplotypes frequency distribution in different populations is still needed for calculation of probabilities in relationship testing. Published haplotype frequencies from German population data are available, but in different caseworks we found unreported X-haplotypes. To enlarge the forensic X-chromosome database, we present haplotype frequencies and other parameter of forensic interest obtained from 200 anonymous DNA samples of unrelated Italian males for the four linkage groups included in the Investigator Argus X-12 kit. From the comparison of the Italian sample haplotype frequencies with other populations, significant genetic distances were found with Asian and African populations, but not with Europeans. Finally, casework examples of complex kinship analysis are presented.