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The evaluation of four pairs of tightly linked chromosome X (ChrX) short tandem repeat (STR)s at Xp22, Xq12, Xq26 and Xq28 led to the creation of the Argus X 8 multiplex amplification kit. These eight STRs are distributed as four closely linked pairs over the entire X-chromosome, and for practical reasons, they are assigned to four linkage groups 1-4. To achieve a further considerable enhancement in discrimination power, we suggest to include additional markers. A recent paper referred to the earlier evaluation of STR clusters at Xq12, Xq26 and Xq28, and here we present the pending data of linkage group 1 at Xp22. The newly established STR updates the Xp22 STR cluster which now presents three polymorphic markers: DXS10148 (PIC = 0.8556), DXS10135 (PIC = 0.9093) and DXS 8378 (PIC = 0.6454). Typing of 398 X-chromosomes provided 278 different and 200 unique haplotypes. All the other haplotypes observed appeared with frequencies in the range between 0.005 and 0.015. Considering this STR triple in the context with the three further triple clusters Xq12, Xq26 and Xq28 published earlier, we announced the development of a next generation of a ChrX STR cluster typing kit.

Short tandem repeat (STR) markers DXS6801 (GATA41B11), DXS6809 (GATA69B129) and DXS6789 (GATA31F01) are located in a 3-Mb region on human chromosome Xq21, spanning approximately 3-6 cM. Theoretically, this cluster could give rise to 1,144 different haplotypes in the German population. In fact, genotyping of 806 males revealed the presence of 207 different haplotypes. Since the three STRs have been shown to be in strong linkage disequilibrium (LD), haplotype frequencies cannot be computed on the basis of single locus allele frequencies alone, but have to be estimated directly instead. In this work, we present data on linkage, haplotype frequencies and LD in the German population. To highlight the potential of the STR cluster for forensic analysis, we also report two examples of its successful application in pedigree-based kinship testing.

The incorporation of reference DNA is crucial to the validation of any DNA typing protocol. This paper aims to provide a panel of reference DNAs for actual forensic profiling strategies, i.e. autosomal and gonosomal STR typing as well as mtDNA sequencing. We have characterised three human lymphoid cell lines, GM9947, GM9948 and GM3657, and considered 58 autosomal and gonosomal microsatellites as well as the mitochondrial control region sequence. Well-established markers and STRs recently developed for forensic use were involved. K562 DNA samples which we purchased from two different suppliers were also analysed. They revealed conflicting results with regard to the ChrX STR marker genotype. Hence, we suggest that K562 is no longer used for the calibration of profiling techniques. Our investigation establishes a panel of one female and two male DNA samples as an STR allelic ladder calibration tool and offers information on six alleles of each autosome (AS) marker, three alleles of each X chromosome (ChrX) marker and two alleles of each ChrY marker. In addition, sequences of the mitochondrial control region of the three DNAs are communicated in order to provide sequencing quality control.

This paper presents an example of deficiency paternity testing by using 15 chromosome X (ChrX) markers. The special power of ChrX typing in deficiency kinship testing is demonstrated. In the case of investigation, ChrX haplotyping confirmed the claim of the disputed offspring to be related to the deceased putative father.

Allele frequencies for 16 X-linked STRs, suitable for forensic purposes, were obtained from a sample of unrelated German individuals (male and female), The presented data show also repeat sequence structures and statistic parameters describing there information content.

The paper presents results of forensic mitochondrial DNA analyses which were aimed at typing the traces caused by touching or abrasion of skin cells. Five cases of strangulation tool investigation are summarised. Two cases of homicide could be cleared up by identifying the mtDNA of both the victim and the suspect on cables which had obviously been used as strangulation tools. In eight of 10 cases, weapons could be reliably assigned to their users. The mtDNA of the users could be even detected on cartridges after firing. In one case, evidence of a suicide could be provided by means of mtDNA sequencing of the wiping traces on a suicide note.

At the forensic autopsy of a sexual murder victim, some trace hairs, possibly belonging to the perpetrator, were saved. Initially, the analysis of a pubic hair shaft only revealed the presence of the mitochondrial (mt) DNA haplotype profile consisting of the (CA)(6) allele and the complete hypervariable region 1 (HV1) and 2 (HV2) sequence. Later, typing of some further telogene trace hairs, which had been stored for several years, yielded a nuclear short tandem repeat (STR) profile. We used both the mtDNA haplotype and the STR profile to start a DNA mass screening project involving 2,335 male citizens of the relevant communities. MtDNA screening was carried out by using the CA repeat amplification in combination with an SNP typing procedure based on the restriction site analysis of amplified d-loop sequences. The aim of our paper is to put mass screening with mtDNA up for discussion.

Sequence analysis of the human mitochondrial genome (mtDNA) has proven to be a valuable tool in forensic identity testing and the analysis of crime scene stains. In contrast to the very expensive sequencing technique, typing of different length variants can greatly facilitate screening of a large number of traces for their relevance during casework. Within the mitochondrial control region, a dinucleotide (CA) n repeat locus is present. To assess the discrimination power of this marker, we have determined (CA) n allele distribution and the frequency of heteroplasmy in a population sample of 2,458 Germans. The inclination to develop heteroplasmic mixtures (CA) n /(CA) n−1 was positively correlated with the number of CA repeats in the mtDNA. In addition, we have studied the inheritance patterns of (CA) n repeat sequence heteroplasmy in two pedigrees. In one pedigree, we also found a length heteroplasmy in the homopolymeric C-tract (nt 303–309). Our data show stable inheritance of heteroplasmy within the homopolymeric C-stretch, but rather unstable inheritance regarding the (CA) n repeat locus.

The hypervariable tetranucleotide STR polymorphism DXS10011 is a powerful marker for forensic purposes. Investigation of this STR led to an allele nomenclature which is in consensus with the ISFG recommendations. DXS10011 is located at Xq28 and genetically closely linked to DXS7423 and DXS8377 but is unlinked to HPRTB and more distant X-chromosomal STRs. DXS10011 is a very complex marker exhibiting some structural variants within alleles of identical length. Two types of repeat structure (regular and inter-alleles) are known and described as types A and B. Two SNPs which are in strong linkage disequilibrium to the different sequence types were found in the repeat flanking region. The type A sequence consists of a long stretch of uninterrupted homogenous repeats which is highly susceptible to slippage mutation during male meiosis.

This paper presents sequence and population genetic data of the microsatellite marker DXS6809 (GDB 365492) obtained from a German population sample ( n=725 chromosomes). DXS6809 is a highly polymorphic X-linked tetranucleotide polymorphism presenting 12 alleles in our population. Sequencing of 77 PCR products covering 12 alleles (by length), characterised DXS6809 as a marker with a complex repeat sequence structure. A polymorphism information content (PIC) of 0.825 and a mean exclusion chance (MEC) of 0.815 were obtained. A deviation from the Hardy-Weinberg equilibrium (HWE) could not be detected and male and female samples exhibited a similar allele distribution. Kinship testing revealed a typical X-linked inheritance and 2 mutations were found in 394 meioses. DXS6809 is located 90.18 Mb, i.e. 102.3 cM, from the Xp-telomere (Xp-tel), corresponding to Xq21.33. The presented data qualify DXS6809 as a useful supplement to the known forensic ChrX marker panel.

X-linked DNA markers are increasingly used in forensic kinship testing. This paper presents sequencing data of the short tandem repeats (STRs) DXS9895, DXS8378, DXS7132, DXS6800, DXS7133, GATA172D05, DXS7423, DXS8377 and proposes an allele nomenclature. Alleles were assigned according to the recommendations of the International Society of Forensic Genetics (ISFG) Commission.

We report a case in which STR typing failed to identify the minor component of a mixed saliva stain, but a mitochondrial restriction analysis succeeded in discriminating between the two components. To identify the nt16093 and nt16265 transitions, the template was amplified with the mismatch primers L16092-mm16085 and H16266-mm16269. In the presence of the transitions the mismatch primers created a BsaB I and a Cac8 I restriction site, respectively. Subsequently, aliquots were restricted separately using the enzymes Cac8 I and BsaB I which clearly identified the minor stain component.

This report gives the results of two population studies on HumD3S1358 from a northern and a southern region of Germany. The numbers of unrelated individuals were 326 and 666, respectively and seven main alleles, three rare allelic variants and 29 different genotypes were encountered. No significant statistical differences were seen between the northern and southern populations. The HumD3S1358 allele distributions were in agreement with Hardy-Weinberg expectations and two mutations were found in 780 meiotic events.

We report a dinucleotide repeat polymorphism in the 3′ area of the mitochondrial control region. The fragments obtained using a new primer set could be reliably separated by polyacrylamide gel electrophoresis (PAGE) using nondenaturing gels. A total of five alleles [(CA)3 to (CA)7] were detected on silver-stained gels. The 90 bp product corresponds to allele 5. Samples from one African and three European populations were characterized. Significant differences could be demonstrated as to the incidence of single alleles and allele distributions in different populations. These differences were found between the three European and one African Bantu population. For specific forensic questions the mitochondrial CA repeat is well suited. Gene diversities in populations of Germany, Hungary, the Russian Federation and Cameroon were 0.36, 0.40, 0.34, 0.52, respectively.

For extracting the full information about stains or an identification situation, it is advisable to investigate karyotic STR systems as well as mitochondria (mt) DNA. Each of the above strategies is associated with special advantages and disadvantages: 1. Due to the high number of mt copies per cell, it is a much higher sensitivity what distinguishes mt testing from other methods. 2. Since mt concerns maternally inherited markers, it avoids wrong results due to illegitamate paternities. 3. mt testing can be superior if mixed stains have to be investigated. Stain sorting by cloning is possible.

STR polymorphisms differ in the number of the tandem repeats. However, in addition, a microheterogenity, as far as the sequence variation is concerned, has been detected in some systems (HumVWA and others) (Moller 1994). The aim of our paper is to demonstrate the usefulness of the heteroduplex (HD) analysis (HDA) for the detection of suballeles in DNA systems such as HumVWA (Kimpton 1992), HumCD4 (Edwards 1991) and Hum Dysl9 (Roewer 1992). The HDA is a well-established technique (Wilkin 1993) but, to our knowledge, HDA is not usual in forensic application. During PCR amplification, the DNA products are submitted to a melting and a reassociation process. In case of a homozygous genotype, the reassociation produces only homoduplexes. However, if there are DNA fragments with different numbers of repeats and/or significant differences concerning the sequence, the reciprocal association produces two or more types of HDs in addition to homoduplexes. On dependency on the extension of the missmatch area, the HDs migrate noticeably slower than homoduplexes in the nativePAGE. Thus, HD can provide several pieces of information which remain hidden, if only measurements of the length are performed.

After a party, which included 3 males and 4 females, one of the females was found dead in an adjoining room. The corpse was clothed in a nightie, which was pulled up to the neck. The cause of death was strangulation. Although the age of the dead person was 60 years and no sperma was found, the offence is believed to have been sexualy motivated. Five bite marks were found at the upper part of the arms(2x), at the tummy (1x) and at the bottom.