Application of computerised correction method for optical distortion of two-dimensional facial image in superimposition between three-dimensional and two-dimensional facial images.

The applicability of computerised correction of optical distortion to two-dimensional (2D)/three-dimensional (3D) facial image superimposition was investigated. Two-dimensional (2D) facial images of 10 male volunteers were taken with a commercially available closed circuit device (CCD) camera (reference camera) at four areas of the lens field: the centre, top, upper right and right. Correction was made by computer by calculating differences vis-à-vis the co-ordinates of dots on a test chart. Discrepancies in facial outlines between the 3D and 2D images decreased following correction in all lens fields and were below the threshold for true positive. The correction method was also tested using an actual surveillance camera and video recorder installed in a bank. The method was found to be effective for the correction of facial images, especially those taken in the top and right lens fields. Since the total error (observed error) remaining after correction appeared close to the random error (real error), systematic error was thought to be minimised by correction. Therefore, the present method was thought to display high fidelity, and could be useful for supplementary examination of conventional superimposition.

Distinct breakpoints in two cases with deletion in the Yp11.2 region in Japanese population.

The amelogenin gene on the Y chromosome (AMELY) is a homolog of the X chromosome amelogenin gene (AMELX), and the marker is employed for sexing in forensic casework. Deletion of the sequences in the Yp11.2 region containing the AMELY locus has been found in males from various ethnic populations. Two cases of AMELY null males found in the Japanese population had different Y haplogroups and deletion mapping. Proximal and distal breakpoints of a sample of haplogroup D2* were located in TSPYA and TSPYB arrays, respectively, suggesting that the deletion mechanism was non-allelic homologous recombination (NAHR). On the other hand, a sample of haplogroup O3a3c* had the distal breakpoint in the TSPYB array and the proximal breakpoint at position 7.94 Mb, not in the TSPYA array. The likely deletion mechanism is non-homologous end-joining. High-resolution STS mapping in the TSPYB array showed the distal breakpoints differed according to the haplogroups. The deletion length was estimated as 3.1-3.7 Mb and 1.6-1.7 Mb for the sample of haplogroup D2* and O3a3c*, respectively. These deletion events should have occurred independently.

DNA analysis of family members with deletion in Yp11.2 region containing amelogenin locus.

For personal identification of two male bodies discovered at the scene of a fire, autosomal and Y chromosomal STR of the two cadavers and of two living male relatives were genotyped. The four males were incorrectly typed as female due to the lack of the amelogenin Y homolog, whereas all loci of Y-STR except for DYS458 were successfully genotyped. Because PCR of Y-specific amelogenin (AMELY) and DYS458 loci failed to amplify target products when using additional primer sets, it was concluded that deletion in the Yp11.2 region containing the loci of AMELY and of DYS458 on the Y chromosome, rather than mutation in the annealing region of the primer sets, had occurred. Investigation using Y-specific markers showed the deletion extending approximately 2.56 Mb in the Yp11.2 region. The variety of deletion sizes and Y-STR haplotypes among AMELY negative males presented to date suggests that the mutation of the Yp11.2 region occurs independently in different ethnic groups. A study on the frequency of the AMELY deletion in the Japanese population would be helpful for future criminal investigation.