Celebrity Suicides and Their Differential Influence on Suicides in the General Population: A National Population-Based Study in Korea

OBJECTIVE: Although evidence suggests that there is an increase in suicide rates in the general population following celebrity suicide, the rates are heterogeneous across celebrities and countries. It is unclear which is the more vulnerable population according to the effect sizes of celebrity suicides to general population. METHODS: All suicide victims in the general population verified by the Korea National Statistical Office and suicides of celebrity in South Korea were included for 7 years from 2005 to 2011. Effect sizes were estimated by comparing rates of suicide in the population one month before and after each celebrity suicide. The associations between suicide victims and celebrities were examined. RESULTS: Among 94,845 suicide victims, 17,209 completed suicide within one month after 13 celebrity suicides. Multivariate logistic regression analyses revealed that suicide victims who died after celebrity suicide were significantly likely to be of age 20-39, female, and to die by hanging. These qualities were more strongly associated among those who followed celebrity suicide with intermediate and high effect sizes than lower. Younger suicide victims were significantly associated with higher effect size, female gender, white collar employment, unmarried status, higher education, death by hanging, and night-time death. Characteristics of celebrities were significantly associated with those of general population in hanging method and gender. CONCLUSION: Individuals who commit suicide after a celebrity suicide are likely to be younger, female, and prefer hanging as method of suicide, which are more strongly associated in higher effect sizes of celebrity suicide.

Sequence Variations and Haplotypes of the GJB2 Gene Revealed by Resequencing of 192 Chromosomes from the General Population in Korea

OBJECTIVES: Hearing impairment (HI) is the most common sensory deficit in human. The Gap Junction Protein, Beta-2 (GJB2) gene encodes the protein connexin 26, and this gene accounts for up to half of the cases of autosomal recessive nonsyndromic HI. This study was conducted to obtain a set of sequence variations (SVs) of the GJB2 gene among Koreans from the general population for making molecular genetic diagnoses and performing genetic counseling. METHODS: We resequenced the GJB2 gene in 192 chromosomes from 96 adult individuals of Korean descent and who were without a history of hearing difficulty. The data of the SVs was obtained and the haplotypes were reconstructed from the data. RESULTS: Five SVs were observed, including a novel one (c.558G>A; p.T186T), with the allele frequencies ranging from 0.5% (1/192) to 41% (79/192). The linkage disequilibrium study and haplotype construction showed that some of the SVs are in tight linkage, resulting in a limited number of haplotypes. CONCLUSION: We observed SVs of the GJB2 gene with different allele frequencies, and a limited number of haplotypes were constructed. The data from this study can be used as reference data for GJB2-related hearing genetic studies, including studies on the founder effect and population genetics, and this data is particularly relevant to people of East Asian decent.

In Silico Functional Assessment of Sequence Variations: Predicting Phenotypic Functions of Novel Variations

A multitude of protein-coding sequence variations (CVs) in the human genome have been revealed as a result of major initiatives, including the Human Variome Project, the 1000 Genomes Project, and the International Cancer Genome Consortium. This naturally has led to debate over how to accurately assess the functional consequences of CVs, because predicting the functional effects of CVs and their relevance to disease phenotypes is becoming increasingly important. This article surveys and compares variation databases and in silico prediction programs that assess the effects of CVs on protein function. We also introduce a combinatorial approach that uses machine learning algorithms to improve prediction performance.

Distinct Linkage Disequilibrium (LD) Runs of Single Nucleotide Polymorphisms and Microsatellite Markers; Implications for Use of Mixed Marker Haplotypes in LD-based Mapping

It has been suggested that the haplotypic relationship between microsatellite markers and single nucleotide polymorphisms (SNPs) is of considerable importance, as microsatellite markers can potentially be incorporated into haplotypes containing SNPs to increase marker density across a region of interest. However, SNPs and microsatellite markers have different mutation rates and durations, and it is conceivable that the linkage disequilibrium (LD) patterns between the genetic markers may considerably differ. We assessed the LD patterns using 1,661 SNPs and 65 microsatellite markers along chromosome 22 and investigated whether common patterns of LD between the two genetic markers are deduced from the results. The results demonstrated that the patterns of LD among microsatellite markers varied considerably and the LD runs of SNPs and microsatellite markers showed distinct patterns. Microsatellite markers have a much higher mutation rate and the evolution of microsatellite markers is a more complex process which has distinct mutation properties from those of SNPs. We consider that these might contribute to the different LD patterns between the two genetic markers. Therefore, it would seem inadvisable to make assumptions about persistence of LD across even a relatively small genetic distance among microsatellite markers and to construct mixed marker haplotypes/LD maps employing microsatellite markers.