In order to apply a set of Y-STRs to the paternity testing of male offspring and to cases of sexual assault, a population study was performed on a sample of 243 Italians. 110 cases of paternity were investigated using the same set of Y-STRs, to establish the additional degree of information compared with already examined autosomal microsatellites.

Collaborative research on the polymorphism of the STR locus HumFGA was carried out by the Institutes of Legal Medicine in four Italian regions (Marches, Veneto, Lombardy and Tuscany). The aim was to establish a database of allelic frequencies with a view to applying HumFGA in forensic identification and paternity testing. The goal for each participating laboratory was to study at least 100 genotypes of unrelated, locally residing individuals. The results of statistical analysis were highly informative (PD = 0.96 and mean exclusion change = 0.71) suggesting that this system is a powerful tool for forensic routine.

The tetrameric (ATTT) short tandem repeat HUMFES/FPS system, located on chromosome 15 (15q25-qter), displays a polymorphism (Polymeropoulos et al. 1991) which has been investigated for forensic purposes (Hammond et al. 1994). The aim of the present work was to study the polymorphism of this system in a large Italian population sample: 1) to verify allele frequency distribution, 2) to check whether allele frequencies show inter-regional differences, 3) to evaluate the effectiveness of this system for paternity testing and personal identification. For this purpose, collaborative research was performed on subjects from four Italian regions in laboratories of the Institutes of Legal Medicine of the Universities of Pavia (Lombardy), Parma (Emilia), Pisa (Tuscany) and Ancona (Marches).

The structural gene of factor B (BF), a component of the alternative complement pathway, is located in the class III region of the major histocompatibility complex (MHC) centromeric to the C2 gene and between the C4 and HLA B genes. Alpern et al (1972) first reported polymorphism of BF, by using immunofixation agarose gel electrophoresis: they identified two common (F and S) and two less common (Fl and S1 = S0.7) alleles, codominant at the same locus. Subsequently, a number of rare variants have been described and a nomenclature has been proposed (Geserick et al 1990). Further isoelectric focusing (IEF) studies revealed the occurrence of BF subtypes (Teng et al 1982; Geserick et al 1983) which could not be demonstrated by standard electrophoresis.

Over the years there has been a continuous increase of the number of genetic polymorphisms which have become available for paternity testing. The range has extended from the red blood cell groups, through serum proteins and erythrocyte enzymes polymorphisms to white cells antigens of the HLA system. With these “classical” markers, the use of several laboratory techniques is needed to achieve a sufficiently high standard of efficiency both in paternity exclusion and inclusion.

The APO B VNTR locus is located next to the 3′ end of the apolipoprotein B gene and consists of a series of AT rich tandem repeats, each 14–16 bp long (for a review about the genetic relationship between the 3′-VNTR and diallelic apolipoprotein B gene polymorphism, see Renges et al, 1992; for a recent proposal of a molecular model, see Desmarais et al 1993). Its polymorphism was described by Boerwinkle et al (1989) and by Ludwig et al (1989) using the PCR technique. Since then, the APO B has become a genetic marker quite frequently used in forensic practice.

The genetic polymorphism of haptoglobin (HP) has been first observed, through starch gel electrophoresis, by Smithies et al (1955), who demonstrated three common phenotypes: HP 1, HP2-1 and HP2. The HP-α chain, which carries the polymorphism, has subsequently been shown to exist in several additional allelic forms (“subtypes”) - 1S, 1F, 2FS, 2FF and 2SS - giving rise to three different HP1, six different HP2-1 and six different HP2 phenotypes. Only in the last few years, however, methods suitable for routine HP subtyping have been developed.

HUMTH01 polymorphism, first described by Edwards et al (1991), is due to a variation in the length of a tetrameric short tandem repeat on locus 11p15.5. Seven alleles were identified in the range 183–207 bp (Edwards et al 1992).

RFLP (restriction fragment-lenght polymorphism) at the D2S44 locus, detected by the highly polymorphic probe YNH24 (Nakamura et al. 1987), can be used as an efficient tool in stain and paternity testing, as long as reliable fragment size frequencies are available (see van Eede et al. 1991, Gill et al. 1991, Budowle et al. 1991).