Y Haplogroup Distribution in Korean and Other Populations / 대한법의학회지

With globalization, international exchange has increased. Accordingly, the necessity for individual identification using genetic polymorphism has also increased. Paternal lineages are distributed differently, and different distribution patterns can be used to predict ancestry. We studied the distribution pattern of different paternal lineages in Korea and compared them with other populations. All 30 SNPs on the Y chromosome were selected for paternal lineage confirmation. Loci that could subclassify haplogroup O, the most frequent in the East Asian population, were added. After multiplex amplification for the target loci, SBE reactions were set up for each SNP site. One hundred Korean men as well as 60 Chinese, 60 Japanese, 19 African-American, 48 Caucasian, and 47 Mexican American were tested and compared. Five Y haplogroups [C (C3), D (D2), NO, O, Q (Q1a1)] were found in Koreans, with haplogroup O being the most frequent. Haplogroup O sub-classified into O* (24%), O1 (6%), O2b (39%), O3a3c (4%), O3a3c1 (13%), and O3a3b(1%). This distribution pattern was similar to that of Chinese or Japanese, but minor differences were noted. With Fst, the Korean and Japanese patterns were close (0.01757) when using 6 SNPs. There were significant differences between Koreans and African Americans, Caucasians and Mexican Americans, and they were easily discernible without requiring haplogroup O sub-classification. Sub-classification of haplogroup O is likely to be useful for East Asia group comparisons. Additional studies in populations from different areas of China or Japan or studies of mtDNA or autosomes may enhance the discrimatory power of genetic polymorphism in different Asian populations.

DNA Database Searching Using Genetic Relationship / 대한법의학회지

The usefulness of DNA databases is well known. In Korea, many cases have been solved since the establishment of DNA databases in 2010. DNA profiles obtained from criminal evidence are analyzed and are kept in databases, and matching profile is searched. On the matching occasion, DNA databases can provide some investigative information. Close family members, for example father, son or brother, share more alleles than unrelated people. This genetic closeness can be searched using the so called familial searching, and many successful cases have been reported. Management of DNA databases including familial searching needs continuous monitoring and control, especially from ethical view points. Many different views for familial searching have been presented, and each country running DNA databases has their own different policies. We present the utility, approaches and different policies of familial searching as well as arguments for and against familial searching. We also suggest that our appropriate guidelines be mandatory and a proper administrative process be prepared for the start of familial searching.

Experience on Sequencing of Mitochondrial DNA from 1200 Year Old Bone Using Cloning / 대한법의학회지

Ancient bones have undergone natural decomposition and have been exposed to external environment for long period. Ancient DNA from old bone is usually fragmented. In addition, various kinds of inhibitors are co-extracted. All these may inhibit proper sequencing reaction. Cloning is regarded as the standard method when sequencing aDNA. When cloning, each clone from the same sample may not be of same sequence, and to exact consensus sequence may be difficult. Here we present our experience on 1200 year old bone from Russia, Primorsky Kray area. We have tried to sequence for HV I, II region of mtDNA using modified mini-primer set, which consisted of 7 set to cover the HV I, II. We cloned the PCR product and sequenced all the clones. Amplification efficiency and subsequent success rates were different for each mini primer set. Loci of variation that differ from consensus sequences were rather frequent, and the pattern were variable depending on sample. Except major polymorphic sites that are important when haplogroup designation, 16129 was the most frequent site that was discarded when extracting haplogroup designation.

Species Specificity of a Commercial AmpFLSTR(R) MiniFiler(TM) PCR Amplification Kit / 대한법의학회지

Recently forensic scientists have focused on extending the applicability of STR to degraded or tiny amount DNA. Short amplicon may be one of the solutions to these samples and several commercial kits are available for this purpose. Before practical casework, validation is necessary for newly introduced kit. We tried to check how newly introduced STR kit, AmpFLSTR(R) MiniFiler(TM) PCR Amplification Kit, reacts with some animal DNAs. We tried 27 animal DNA samples and checked whether the above kit amplify animal DNA, and next how the band appears on electropherogram. We compared the results with popular STR kits. With AmpFLSTR(R) MiniFiler(TM) PCR Amplification Kit, we could get several bands on electropherogram for some species, but we could not designate proper allelic number compared to allelic ladder for most loci except the following loci, D13S317, D2S1338, D21S11, D18S51, FGA. The D18S51 locus was outstanding in that some species showed definite designated alleles, but the allelic number was not different depending on species. This was the same with another popular STR kit, AmpFLSTR(R) Identifiler(TM) PCR Amplification Kit, which was from the same company. The another kit from another company, PowerPlex(R) 16 System showed different phenomenon with more increased number of amplified bands which were usually differ on size when compared to allelic ladder.

Efficiency of Quantification using QuantifilerTM Human DNA Kit in 60 Year Old Bone / 대한법의학회지

Commercial kits usually recommend certain range of the amount of DNA without PCR inhibitors for optimal results. If proper DNA is not used in STR amplification, undesirable results such as enhanced stutter effects, split peaks, allele dropout and poor peak balance could be shown. This phenomenon would happen more frequently in case of bone typing. Therefore, we checked effect of DNA concentration and PCR inhibitors on conventional STR typing results using QuantifilerTM Human DNA Quantification Kit. The 54 bone samples over a 60-year burial period were used in this study. In all samples, the DNA concentration ranged from 0.8 pg/ul to 748 pg/ul and Ct values of IPC that indicates residue of PCR inhibitors ranged from 26.69 to 35.59. The DNA concentration and the number of amplified loci showed positive correlation. The number of loci amplified using Minifiler kit was much more than using Y filer kit. Samples with high Ct value of IPC were not almost amplified with Y filer kit. These results suggested that QuantifilerTM Kit is useful to obtain information for DNA typing.

Korean Guidelines for DNA Typing in Forensic Field / 대한법의학회지

The field of forensic DNA requires not only genetic typing but also social systems. The systems include the establishment of Korean guidelines for DNA typing. There were some publications relating DNA typing guidelines in 2001 and 2002, but the works could not be sustained. Although KOLAS and KIGTE are operating now, we can hardly say that these are optimal for forensic purposes. There also have been foreign publications about the DNA typing guidelines. Considering various differences among nationality, however, we need to establish suitable guidelines for Korean. Therefore, expert members in forensic society should be concern about Korean guidelines for DNA typing and participate in this work.

Three Allele Pattern Detected by STR Typing / 대한법의학회지

STR typing for several loci has been regarded as a standard method for individual identification. The result is rather simple and easy to be interpreted. For each loci one allele for homozygote and two different alleles for heterozygote are expressed as simple peaks. Many peaks more than two suggest unusual situations such as contamination. We experienced two cases of three alleles in two separate samples. Among 15 STR loci typed using AmpFlSTR.. Identifiler.. Kit(Applied Biosystems, Foster City, CA) and Powerplex..16 system (Promega, Madison, WI), three alleles were noted in D8S1179 locus in one sample, in D21S11 locus in another sample. We sequenced all the three amplified alleles through cloning to reveal the structure, and amplified nearby regions to check the extent of three alleles. We present the results here together with review on many alleles in one sample.

Unusual mtDNA sequencing results from ancient DNA / 대한법의학회지

Sequence analysis of human mitochondrial DNA(mtDNA) is being used widely to characterize individual identification, particularly when there is insufficient nuclear DNA in samples for typing. Hair shafts, bones, teeth and other samples that are severely decomposed may be subjected to mtDNA analysis. As sample decomposes, however, the possibility of mtDNA to be degraded becomes high and the possibility of spurious results becomes high. In this case mtDNA sequencing results must be carefully analyzed. We got unusual results while typing two human bone samples, which were not compatible with human mtDNA sequence. Bones were about 50 and 35 years old. We report the results with discussions about ancient DNA sequencing.

Clinical Experiences of New Intermaxillary Fixation Method without Tooth Ligation

In the treatment of maxillofacial injuries, proper intermaxillary fixation is very important in improving bone union and restoration of normal occlusion. The traditional methods of intermaxillary fixation consist of interdental wiring and ligating of arch bars to the teeth of each jaw. These methods have their fixation point within the tooth, which may afflict the tooth itself. The tooth ligation method is also unsatisfactory for partially or totally edentulous patients, necessitating adjunctive circumferential wiring and acrylic splint to effect fixation. Furthermore, because of excessive manipulations (about 14-20 wire) during interdental wiring, it increases the possibility of associated gingival and mucosal injuries, and infections acquired during operation due to skin punctures. The authors have devised an improved method of placing miniscrews into the maxilla and mandibular alveolar bone and using these miniscrews for points of intermaxillary fixation. This procedure has been used in 17 patients with variable mandible fracture. In these cases we obtained better results than those with teeth ligating methods. The advantages of author's method include easy placement and removal with minimal wiring, decreased operation time, decreased patient discomfort, reduced risk of tooth, periodontal tissues, and oral mucosa injuries, and reduced risk of delivering blood transmitted diseases (AIDS, hepatitis) by skin puncture. As far as the stabilization and oral hygiene are concerned, fixation method was found to be superior to tooth ligation methods. Moreover, in patients with multiple dental injuries, author's intermaxillary fixation method proved to be simple and safe. With these advantages, new intermaxillary fixation method without tooth ligation is very useful for mandibular fractures and maxillofacial operations.