Genetic polymorphism of mitochondrial DNA HVS-I and HVS-II of Chinese Tu ethnic minority group

We analyzed the two hypervariable segments HVS-I and HVS-II of 108 Chinese Tu ethnic minority group samples for forensic and population genetics purposes, Comparing with Anderson sequence, 79 polymorphic loci in HVS-I and 40 in HVS-II were found in Chinese Tu ethnic minority group mtDNA sequences, and 90 and 64 haplotypes were then defined. Haplotype diversity and the mean pairwise differences were 0.9903±0.0013 and 5.7785 in HVS-I, and 0.9777±0.0013 and 3.5819 in HVS-II, respectively. By analyzing the hypervariable domain from nucleotide 1,6180 to 1,6193 in HVS-I, we defined some new types of sequence variations. We also compared the relationship between Tu population and other populations using mtDNA HVS-I sequences. According to Rst genetic distances, the phylogenetic tree showed that the Tu population, the Xi＇an Han population, the Chinese Korean, and the Mongol ethnic group were in a clade. This indicated a close genetic relationship between them. There were far relations between the Tu population and other Chinese southern Han populations, Siberian, European, African, and other foreign populations. The results suggest that Tu population has a multi-origin and has also merged with other local populations.

Genetic Analysis of 15 STR Loci in Chinese Han Population from West China

Allele frequencies for 15 short tandem repeat （STR） loci （D8S1179, D21S11, D7S820, CSFIPO, D3S1358, TH01, D13S317, D16S539, D2S1338, D19S433, vWA, TPOX, D18S51, D5S818, and FGA） were obtained from 7,636 unrelated individuals of Chinese Han population living in Qinghai and Chongqing, China. Totally 206 alleles were observed, with the corresponding allele frequencies ranging from 0.0001-0.4982. Chi-square test showed that all of the STR loci agreed with the Hardy-Weinberg equilibrium. We also compared our data with previously published population data of other ethnics or areas. The results are valuable for human identification and paternity testing in Chinese Han population.

Distributions of HLA-A and-B alleles and haplotypes in the Yi ethnic minority of Yunnan, China: relationship to other populations

Objective: To investigate the distributions of human leukocyte antigen (HLA)-A and-B alleles and HLA-A-B haplotypes in the Yi ethnic minority of the Yunnan Province, situated in southwestern China. Methods: DNA typing for HLA-A and-B loci was performed using the polymerase chain reaction-sequence-based typing (PCR-SBT) method on 114 randomly selected healthy individuals of the Yi population. The allelic frequencies of HLA-A and-B loci were calculated by direct counting and HLA-A-B haplotypes were estimated using the expectation maximization algorithm. Results: A total of 17 HLA-A and 38 HLA-B alleles were found in the Yi population. The most frequent alleles were A2402 (32.46%), A1101 (26.32%), and A0203 (10.09%) at the HLA-A locus and B4601 (12.28%), B1525 (10.09%), B4001 (8.77%), and B3802 (7.89%) at the HLA-B locus. The predominant HLA-A-B haplotypes were A2402-B1525 (7.86%) and A0203-B3802 (5.64%), followed by A1101-B4001 (4.69%). Phylogenetic analysis indicates that the Yi population in the Honghe, Yunnan Province of China basically belongs to groups of southeastern Asian origin, but shares some characteristics with northeastern Asian groups. Conclusion: The present study may add to the understanding of HLA polymorphism in the Yi ethnic group that was poorly defined previously, and provide useful information for bone marrow transplantation, anthropological research, and forensic sciences as well as for disease-association studies.

Characteristics of Suicides Caused by Drug Overdose in the State of Maryland

Suicidal drug overdose is a major public health issue.In the United States,every year more than 33,000 people commit suicides.Our study focused on the characteristics of suicide victims in the state of Maryland.Material and methods:This study was a retrospective review of autopsy cases of all suicide deaths caused by drug(s)or drug(s)with alcohol intoxication investigated by the OCME in Maryland over a 7-year period from January 2004 to December 2011.All deaths investigated by the OCME that require autopsy examination are subject to comprehensive toxicology testing for drugs and alcohol.The screen tests were performed using gas chromatography(GC)and radioimmunoassay techniques.All detected drugs and/or metabolites were confirmed using GC-mass spectrometry(GC-MS).Results:From 2004 to 2011,434 deaths were certified as suicide.Of the 434 suicidal overdose deaths,84%were white,11%were African-American,and about 5%were either Hispanic or Asian.The male and female ratio was almost equal.Their ages ranged 15-82 years.Of the 434 suicidal drug overdose deaths,277 victims(63.8%)consumed a single drug type and 157(36.2%)consumed more than one type of drug.Of the 277 single-drug overdose cases,71.1%suicides were due to prescription drugs,23.5%due to over-the-counter drugs,and 5.4%due to street/recreational drugs.Among single-type prescription drugs,analgesic(N=76),antidepressant(N=45),and neuroleptic(N=35)classes were the three leading type of drugs used in suicidal deaths.Oxycodone,morphine,quetiapine,and amitriptyline were the most common prescription drugs in suicidal overdose.Diphenhydramine was the leading over-the-counter drug.Of the 157 victims who consumed more than one drug,combined prescription drugs were present in 54.1%,mixed prescription and overthe-counter drugs in 29.3%,and prescription drugs/over-the-counter drugs and street drugs in 16.6%of cases.Of the multiple-drug overdose suicides,66.2%cases involved antidepressants.Discussion:Suicide is found in every age,racial,and ethnic group.In the USA,poisoning is thethird-leading method of suicide,following firearm injuries and hanging/strangulation.Our study indicates that prescription drugs,such as those in the opioid analgesic,neuroleptic,and antidepressant class(e.g.,oxycodone,morphine,quetiapine,amitriptyline,doxepin,and citalopram),are of special concern in the context of suicidal overdose deaths in the state of Maryland.Therefore,addressing the problems of intentional drug overdose in our society is worthy of public attention.

PRELIMINARY DNA IDENTIFICATION FOR THE TSUNAMI VICTIMS IN THAI-LAND

The 2004 Southeast Asia Tsunami killed nearly 5,400 people in Southern Thailand, including foreign tourists and local residents. To recover DNA evidence as much as possible from the seriously decomposed bodies, we explored procedures of sample preparation from both bone and tooth samples as well as both mitochondrial and nuclear markers. Despite having failed to recover enough DNA for nuclear marker typing, we succeeded in obtaining fully informative results for mitochondrial markers （HV1 and HV2） from 258 tooth samples with a success rate of 51% （258/507）. Using an organic DNA extraction method coupled with an ultrafiltration step, we obtained 16 STR （including 13 CODIS loci, one sex discrimination locus, and two Identifiler loci） profiles for 834 samples with a success rate of 79% （834/1,062）. In addition, by comparing the allelic frequencies between the typed samples as a group and other index populations, we conclude that the Thai tsunami victims are a combined group of several populations. Our results provide valuable evidence and protocols for the future forensic practice.