Phenotypes of inter-alpha-trypsin-inhibitor (ITI) have been determined by isoelectric foCUSing on polyacryl-amide gels followed by immunofixation. The phenotype fre-quencies of ITI in the Han population in Chengdu. P. R. China have been investigated using this method. In addition, family studies have been conducted in 21 families. The re-suits show that ITI iS polymorphic in the Han population in Chengdu. China. The allele frequencies are as follows: ITI*1=0.5763. ITl*2=0.4107. ITl*3=0.0130. ITI is thus a new and promising genetic marker that can be used in the field of forensic haematogenetics.

The amplifiable VNTR polymorphic system COL2A1 has been investigated in Chinese and German population samples. In order to accurately identify COL2A1 alleles. a number of hu-man allele ladders were prepared. A total of 14 different alleles in 23 genotypes was observed in the Chinese population. while in the German population there were 11 alleles in 24 geno-types. Four new alleles were observed. AIl of them werc found in the Chinese and one was also observed in the German pop-ulation. There was no statisticaI difference in the allele distri-bution between two Gcrman populations from Miinster and Koln, while the allele frequency distribution in the Chinese population differed significantly from the German.

A panel of Y-specific STR loci, including DYS19, DYS389, DYS390, DYS391, DYS392, and DYS393 was analyzed using horizontal nondenaturing polyacrylamide gel electrophoresis with a discontinuous buffer system (horizontal disk-PAGE). In order to obtain correct results for the larger DYS389 and DYS392 alleles, it was necessary to design new primers that bind closer to the repeat region and lead to a significant reduction of the amplified fragment size. Using the modified primer sets the horizontal disk-PAGE results were consistent with a nondenaturing approach using fluorescent primers and a 377 automated sequencer. The modified procedure also amplifies the second repeat stretch at the duplicated DYS389 locus as a single fragment, which results in an immediate allele identification. The results indicate that horizontal disk-PAGE with silverstaining is a simple approach to type the recommended Y-specific STR markers.

In order to evaluate the forensic applicability of the STR locus D20S161 and construct a preliminary database, the genotype distributions and allele frequencies in five populations from three main ethnic groups were investigated, including Germans, Slovakians, African Americans, Japanese and Chinese. A total of 512 samples from unrelated individuals and 85 confirmed father/mother/ child triplets were analyzed by PCR and allele determination was carried out by comparison with a sequenced human allelic ladder. The results showed that D20S161 typing was both precise and reliable. A total of 7 alleles was found in these populations and no evidence of deviation from Hardy-Weinberg equilibrium was observed. Pairwise comparisons between populations showed that there were significant differences in the distributions of the allele frequencies among the three main ethnic groups. No mutation events were observed from the confirmed father/mother/child triplets. With a maximum likelihood method, the mutation rate was indirectly estimated as 2.5 × 10–5. These results suggest that D20S161 is a useful marker for forensic casework and paternity analysis.

Human chromosome Y-specific short tandem repeat (Y-specific STR) markers have useful properties for forensic applications. However, there is a need to develop more Y-specific STR markers because the discriminating power of each STR locus is limited. In the present study, we describe our results on two new Y-specific STR markers, which were initially reported by White et al. [Genomics 57 (1999) 433] as Y-GATA-C4 and Y-GATA-A10. The distributions of alleles and haplotypes for both Y-specific STR loci were studied in a Chinese Han population sample. Allele determination was carried out by comparison with sequenced allelic ladders which were made inhouse. Following the recommendations of the International Society of Forensic Genetics, the allele classification for both Y-specific STR loci was based on the number of repeat motifs. The results show that the haplotype diversity, the power of discrimination and the exclusion probability in the Chinese population for both Y-specific STR loci were 0.9090. The implication from this study is that Y-GATA-C4 and Y-GATA-A10 are useful Y-specific STR markers for forensic DNA typing in Chinese populations.