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Myocardial infarction (MI) is a complex disease caused by combination of genetic and environmental factors. Although genome-wide association studies (GWAS) identified more than 46 risk loci which are associated with coronary artery disease and MI, most of the genetic variability in MI still remains undefined. Here, we screened the susceptibility loci for MI using exome sequencing and validated candidate variants in replication sets. We identified that three genes (GYG1, DIS3L and DDRGK1) were associated with MI at the discovery and replication stages. Further research will be required to determine the functional association of these genes with MI risk, and these associations have to be confirmed in other ethnic populations. [ABSTRACT FROM AUTHOR]

Kawasaki disease (KD) is an acute self-limited vasculitis of infants and children that manifests as fever and signs of mucocutaneous inflammation. Coronary artery aneurysms develop in approximately 15-25% of untreated children. Although the etiology of KD is largely unknown, epidemiologic data suggest the importance of genetic factors in the susceptibility to KD. In order to identify genetic variants that influence KD susceptibility, we performed a genome-wide association study (GWAS) using Affymetrix SNP array 6.0 in 186 Korean KD patients and 600 healthy controls; 18 and 26 genomic regions with one or more sequence variants were associated with KD and KD with coronary artery lesions (CALs), respectively ( p < 1 × 10). Of these, one locus on chromosome 1p31 (rs527409) was replicated in 266 children with KD and 600 normal controls (odds ratio [OR] = 2.90, 95% confidence interval [CI] = 1.85-4.54, P = 1.46 × 10); and a PELI1 locus on chromosome 2p13.3 (rs7604693) was replicated in 86 KD patients with CALs and 600 controls (OR = 2.70, 95% CI = 1.77-4.12, P = 2.00 × 10). These results implicate a locus in the 1p31 region and the PELI1 gene locus in the 2p13.3 region as susceptibility loci for KD and CALs, respectively. [ABSTRACT FROM AUTHOR]

Single nucleotide polymorphisms (SNPs) appeal to the forensic DNA community because of their abundance in the human genome, low mutation rate, small amplicon size, and feasibility of high-throughput genotyping technologies. In an initial screening, we identified six SNP markers of sex determination by resequencing the amelogenin genes and the zinc finger protein genes located on the sex chromosomes. Furthermore, for use in human identification, we selected 30 highly polymorphic autosomal SNP markers from among a human population and examined the potential utility of these SNP markers for human identification. The combined mean match probability of 30 SNP markers was 4.83 × 10−13. Using genotyping data from 8,842 unrelated Korean individuals, we also found that discrimination power increased 10-fold for the addition of every five SNP markers in human identification. In this study, we demonstrated that SNP markers are very useful for sex determination and human identification, even in a very homogeneous population. [ABSTRACT FROM AUTHOR]

Osteoporosis is characterized by impaired osteoblastogenesis. Bone mineral density (BMD) is a major determinant of bone strength. RUNX2 is an osteoblast-specific transcription factor involved in osteoblast differentiation and ossification. To determine whether RUNX2 is associated with BMD in an ethnically distinct population, we investigated SNPs within the two RUNX2 promoters (P1 and P2) using the Illuminar GoldenGate system in 729 postmenopausal Korean women. Subjects bearing the minor homozygote genotype ( CC) at the RUNX2 −1025 T > C SNP (rs7771980) located in P2 showed a significant association with reduced lumbar spine BMD ( p = 0.02) and BMDs at proximal femur sites (trochanter, p = 0.05; total femur, p = 0.04) compared with subjects carrying the major homozygote genotype ( TT) or the heterozygote genotype ( TC), respectively. These results present an interesting genotype association complementary to the previously reported association of BMD with the RUNX2 −1025 T > C P2 SNP in Spanish and Australian cohorts. Therefore, we suggest that the RUNX2 P2 polymorphism ( −1025 T > C) may be a useful genetic marker for bone metabolism and may play an important role in BMD in postmenopausal Korean women. [ABSTRACT FROM AUTHOR]

To identify genetic factors influencing quantitative traits of biomedical importance, we conducted a genome-wide association study in 8,842 samples from population-based cohorts recruited in Korea. For height and body mass index, most variants detected overlapped those reported in European samples. For the other traits examined, replication of promising GWAS signals in 7,861 independent Korean samples identified six previously unknown loci. For pulse rate, signals reaching genome-wide significance mapped to chromosomes 1q32 (rs12731740, P = 2.9 × 10−9) and 6q22 (rs12110693, P = 1.6 × 10−9), with the latter ∼400 kb from the coding sequence of GJA1. For systolic blood pressure, the most compelling association involved chromosome 12q21 and variants near the ATP2B1 gene (rs17249754, P = 1.3 × 10−7). For waist-hip ratio, variants on chromosome 12q24 (rs2074356, P = 7.8 × 10−12) showed convincing associations, although no regional transcript has strong biological candidacy. Finally, we identified two loci influencing bone mineral density at multiple sites. On chromosome 7q31, rs7776725 (within the FAM3C gene) was associated with bone density at the radius (P = 1.0 × 10−11), tibia (P = 1.6 × 10−6) and heel (P = 1.9 × 10−10). On chromosome 7p14, rs1721400 (mapping close to SFRP4, a frizzled protein gene) showed consistent associations at the same three sites (P = 2.2 × 10−3, P = 1.4 × 10−7 and P = 6.0 × 10−4, respectively). This large-scale GWA analysis of well-characterized Korean population-based samples highlights previously unknown biological pathways. [ABSTRACT FROM AUTHOR]

Asthma is a chronic inflammatory disorder of the airways, and a number of genetic loci are associated with the disease. Candidate gene association studies have been regarded as effective tools to study complex traits. Knowledge of the sequence variation and structure of the candidate genes is required for association studies. Thus, we investigated the genetic variants of 32 asthma candidate genes selected by colocalization of positional and functional candidate genes. We screened all exons and promoter regions of those genes using 12 healthy individuals and 12 asthma patients and identified a total of 418 single nucleotide polymorphisms (SNPs), including 270 known SNPs and 148 novel SNPs. Levels of nucleotide diversity varied from gene to gene (0.72×10−4–14.53×10−4), but the average nucleotide diversity between coding SNPs (cSNPs) and noncoding SNPs was roughly equivalent (4.63×10−4 vs 4.69×10−4). However, nucleotide diversity of cSNPs was strongly correlated to codon degeneracy. Nucleotide diversity was much higher at fourfold degenerate sites than at nondegenerate sites (9.42×10−4 vs 3.14×10−4). Gene-based haplotype analysis of asthma-associated genes in this study revealed that common haplotypes (frequency >5%) represented 90.5% of chromosomes, and they could be uniquely identified with five or fewer haplotype-tagging SNPs per gene. Therefore, our results may have important implications for the selection of asthma candidate genes and SNP markers for comprehensive association studies using large sample populations. [ABSTRACT FROM AUTHOR]