• 한국임상수의학회:학술대회논문집
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• 한국임상수의학회 2006년도 추계학술대회 및 정기총회
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• pp.60-60
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• 2006

• Journal of Preventive Medicine and Public Health
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• 제40권2호
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• pp.114-121
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• 2007

Power and sample size estimation is one of the crucially important steps in planning a genetic association study to achieve the ultimate goal, identifying candidate genes for disease susceptibility, by designing the study in such a way as to maximize the success possibility and minimize the cost. Here we review the optimal two-stage genotyping designs for genomewide association studies recently investigated by Wang et al(2006). We review two mathematical frameworks most commonly used to compute power in genetic association studies prior to the main study: Monte-Carlo and non-central chi-square estimates. Statistical powers are computed by these two approaches for case-control genotypic tests under one-stage direct association study design. Then we discuss how the linkage-disequilibrium strength affects power and sample size, and how to use empirically-derived distributions of important parameters for power calculations. We provide useful information on publicly available softwares developed to compute power and sample size for various study designs.

• Tuberculosis and Respiratory Diseases
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• 제53권2호
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• pp.113-126
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• 2002

연구배경 : 폐암의 80-90%는 흡연과 관계가 있으나 흡연자의 일부에서만 폐암이 발생하는 현상은 개체의 유전적 소인이 폐암발생을 결정하는 주요 요인임을 시사한다. 저자들은 한국인에서 DNA 회복 유전자인 XPC 유전자의 codon 499와 codon 939 다형성 그리고 intron 9에 존재하는 poly(AT) 삽입/결손 (PAT) 다형성에 따른 폐암의 위험도를 조사하였다. 방 법 :1998년 1월부터 1998년 12월까지 경북대학교병원 내과에서 병리학적으로 폐암으로 확진된 남자 폐암환자 219명을 대상으로 하였으며 악성종양으로 진단받은 과거력이 있는 사람은 제외하였다. 대조군은 1998년 1월부터 1998년 12월까지 경북대학교병원 건강검진센터를 방문한 40세 이상의 검진자들을 대상으로 하였으며 호흡기질환이나 악성종양이 있는 경우는 제외하였다. 대상인의 나이, 성, 흡연력, 과거력 등은 면접이나 병력지를 통해 얻었으며, 시료는 전혈 5cc에서 DNA를 추출하고 PCR 혹은 PCR-RFLP법을 통해 XPC 유전자의 다형성을 조사하였다. 결 과: 조사한 3부위의 XPC 유전자의 유의한 관계가 없었으며 연령, 흡연력, 흡연 인-년등으로 구분한 경우에도 다형성에 따른 폐암의 위험도는 유의한 차이가 없었다. 폐암의 조직형을 구분하여 비교한 경우에도 XPC 유전자의 다형성과 폐암의 위험도는 유의한 관계가 없었다. XPC 유전자의 Va1499Ala, PAT, Lys939Gln 다형성은 다형성간에 연관비평형 (lingkage disequilibrium) 있었으며, 특히 PAT 다형성과 Lys939Gln 다형성은 kappa 치가 0.87로 높았다. XPC 유전자의 3부위다형성의 haplotype도 폐암과 유의한 관계가 없었으며, 연력, 흡연력, 흡연 안-년, 조직형을 구분한 경우에도 haplotype에 따른 폐암의 위험도는 유의차이가 없었다. 결 론: 한국인에서 XPC 유전자의 codon 499와 codon 939 다형성과 PAT 다형성은 폐암의 위험도를 결정하는 주요 인자는 아닌 것으로 생각된다.

• 생명과학회지
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• 제22권3호
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• pp.366-372
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• 2012

본 연구는 한우 유전체 전장에 존재하는 고밀도 단일염기다형을 DNA chip을 이용하여 각각의 유전자형을 구명하고, 동일염색체 내에 존재하는 각 표지인자쌍의 연관불평형을 성 염색체를 제외한 모든 상염색체에서 추정하여 물리적 거리별 연관불평형의 정도를 확인하고 이러한 결과를 이용하여 한우 집단의 유효집단 크기를 추정하기 위하여 실시하였다. 한우개량사업소에서 2005년부터 2008년까지 후대검정에 공시된 후보종모우 및 후대 검정우 288두에 대해 혈액을 채취하고 Bovine SNP 50 DNA Chip을 이용하여 유전자형을 분석하였으며, 총 51,582 표지인자 중 결측률이 10% 이상인 표지인자 1개 및 다형성이 없는 표지인자 10,730개에 대해 사전제거를 실시하고 남은 40,851개의 SNP표지인자를 본 분석에 활용하였다. 연구 결과, 성 염색체를 제외한 상 염색체의 총 SNP표지인자의 길이는 2,541.6 Mb였으며, 염색체별 평균 SNP표지인자간 거리는 0.55에서 0.74로 분포하였으며, EM알고리즘을 이용하여 염색체별 연관불평형을 추정해 보았을 때, 기존의 보고된 연구와 유사하게 표지인자간 거리가 짧을수록 높게 나타나는 지수형태의 그래프를 나타냈으며, SNP표지인자간 거리에 따른 $r^2$를 보면, 0 Mb에서 0.1 Mb일 때 0.136, 0.1-0.2 Mb에서 0.06로 나타났다. Luo (1998)의 연구결과를 한우에 적용시켰을 때, 전체분산의 5%이상 설명하는 양적형질좌위 발굴을 위해서 약 2,000두의 표현형 자료가 필요할 것으로 사료되었다. 또한 한우의 세대별 유효집단 크기에 대해 추정해 본 결과, 현재 한우의 유효집단크기는 84두로 추정되었고, 지금으로부터 약 50세대 이전의 유효집단 크기는 1,150두로 추정되었다. 가축에서 인공수정이 도입(1960년대)된 이 후 개량의 가속화로 인해 한우의 유효집단 크기가 급격히 감소한 것으로 사료되었다.

• The Korean Journal of Physiology and Pharmacology
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• 제12권2호
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• pp.83-87
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• 2008

The fyn-related kinase (FRK) belongs to the tyrosine kinase family of protein kinases. Recent studies have shown that Frk affects pancreatic beta cell number during embryogenesis and promotes beta cell cytotoxic signals in response to streptozotocin. To investigate the genetic association between FRK polymorphisms and the risk of obesity in Korean population, single nucleotide polymorphisms (SNPs) in the FRK gene region were selected and analyzed. The body mass index (BMI) was calculated, and biochemical data (systolic blood pressure, diastolic blood pressure, hemoglobin A1C, triglyceride, total cholesterol, high density lipoprotein, and low density lipoprotein) of blood sample from each subject were also measured. One hundred fifty five healthy control and 204 overweight/obesity subjects were recruited. Genotype frequencies of six SNPs [rs6568920 (+8391G>A), rs3756772 (+56780A>G), rs3798234 (+75687C>T), rs9384970 (+68506G>A), rs1933739 (+72978G>A), and rs9400883 (+75809A>G)] in the FRK gene were determined by Affymetrix Targeted Genotyping Chip data. According to the classification of Korean Society for the Study of Obesity, control (BMI 18 to < 23) and overweight/obesity (BMI$\geq$23) subjects were recruited. For the analysis of genetic data, EM algorithm, SNPStats, Haploview, HapAnalyzer, SNPAnalyzer, and Helixtree programs were used. Multiple logistic regression analysis (codominant, dominant, and recessive models) was performed. Age and gender as covariates were adjusted. For biochemical data, Student's t test was used. The mean value of BMI in the control and overweigh/obesity groups was 21.1${\pm}$1.2 (mean${\pm}$SD) and 25.6${\pm}$2.0, respectively. All biochemical data of the overweight/obesity group were statistically significance, compared with the control group. Among six SNPs, two linkage disequilibrium (LD) blocks were discovered. One block consisted of rs1933739 and rs9400883, and the other comprised rs3756772 and rs3798234. One SNP (rs9384970, +68506G>A) showed an association with overweight/obesity in the codominant model (p=0.03). Interestingly, the AA genotype distribution in the overweight/obesity group (n=7, 3.5%) was higher than those in the control group (n=1, 0.6%), which is not found in either Japanese or Chinese subjects. Therefore, the AA genotype of rs9384970 may be a risk factor for development of obesity in Korean population. The results suggest that FRK may be associated with overweight/obesity in Korean population.

• The Korean Journal of Physiology and Pharmacology
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• 제12권4호
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• pp.205-209
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• 2008

Recently, Sun et al (2008) reported that the IL6R polymorphism is associated with schizophrenia. Therefore, to detect the association between polymorphisms of interleukin 31 receptor A (IL31RA) and schizophrenia, we genotyped 9 SNPs [rs9292101 (intron 1), rs1009639 (exon 2, Pr043Pro), rs2161582 (intron 2), rs68761890 (intron 5), rs16884629 (intron 6), rs11956465 (intron 12), rs12153724 (intron 12), and rs16884641 (intron 14)] using the Golden Gate assay on Illumina BeadStation 500 GX. Two hundred eighteen patients with schizophrenia and 379 normal subjects were recruited. Patients with schizophrenia were diagnosed according to DSM-IV, and control subjects without history of psychiatric disorders were selected. We used SNPStats, Haploview, HapAnalyzer, SNPAnalyzer, and Helixtree programs for the evaluation of genetic data. Of nine polymorphisms, three SNPs (rs9292101, rs1009639, and rs11956465) were associated with schizophrenia. The rs9292101 and rs11956465 showed significant associations with the risk of schizophrenia in the codominant [rs9292101, odds ratio (OR)=0.74, 95% confidence interval (CI)=0.58${\sim}$0.95, p=0.017] and recessive (rs11956465, OR=0.64, 95% CI=0.42${\sim}$0.96, p=0.034) models, respectively. The rs1009639 also was statistically related to schizophrenia in both codominant (OR=0.76, 95% CI=0.60${\sim}$0.97, p=0.025) and dominant (OR=0.66, 95% CI=0.44${\sim}$0.98, p=0.035) models. Two linkage disequilibrium (LD) blocks were made. In the analysis of haplotypes, a haplotype (GCT) in block 1 and a haplotype (CCACAG) in block 2 showed significant associations between schizophrenia and control groups (haplotype GCT, frequency=0.509, chi square=4.199, p=0.040; haplotype CCACAG, frequency=0.289, chi square=5.691, p=0.017). The results suggest that IL31RA may be associated with risk of schizophrenia in Korean population.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• 제18권2호
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• pp.123-129
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• 2007

Objectives: Autism is a complex neurodevelopmental spectrum disorder with a strong genetic component. Previous neurochemical and genetic studies have suggested the possible involvement of the serotonin system in autism. Tryptophan 2,3-dioxygenase(TDO2) is the rate-limiting enzyme in the catabolism of tryptophan, which is the precursor of serotonin synthesis. The aim of this study was to investigate the association between the TDO2 gene and autism spectrum disorders(ASD) in a Korean population. Methods: The patients were diagnosed with ASD on the basis of the DSM-IV diagnostic classification outlined in the Korean version of the Autism Diagnostic Interview-Revised and Autism Diagnostic Observation Schedule. The present study included the detection of four single nucleotide polymorphisms(SNPs) in the TDO2 gene(rs2292536, rs6856558, rs6830072, rs6830800) and the family-based association analysis of the single nucleotide polymorphisms in Korean ASD trios using a transmission disequilibrium test(TDT) and haplotype analysis. The family trios of 136 probands were included in analysis. 87.5% were male and 86.0% were diagnosed with autism. The mean age of the probands was $78.5{\pm}35.8$ months(range: 26-264 months). Results: Two SNPs showed no polymorphism, and there was no significant difference in transmission in the other two SNPs. We also could not find any significant transmission in the haplotype analysis(p>.05). Conclusion: We could not find any significant statistical association between the transmission of SNPs in the TDO2 gene and ASD in a Korean population. This result may not support the possible involvement of the TDO2 gene in the development of ASD, and further exploration might be needed to investigate other plausible SNP sites.

• Asian Pacific Journal of Cancer Prevention
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• 제15권21호
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• pp.9203-9210
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• 2014

Purpose: To explore associations of CYP2E1 and NAT2 polymorphisms with lung cancer susceptibility among Mongolian and Han populations in the Inner Mongolian region. Materials and Methods: CYP2E1 and NAT2 polymorphisms were detected by PCR-RFLP in 930 lung cancer patients and 1000 controls. Results: (1) Disequilibrium of the distribution of NAT2 polymorphism was found in lung cancer patients among Han and Mongolian populations (p=0.031). (2) Lung cancer risk was higher in individuals with c1, D allele of CYP2E1 RsaI/PstI, DraI polymorphisms and slow acetylation of NAT2 (c1 compared with c2, OR=1.382, 95%CI: 1.178-1.587, p=0.003; D compared with C, OR=1.241, 95%CI: 1.053-1.419, P<0.001; slow acetylation compared with rapid acetylation, OR=1.359, 95%CI:1.042-1.768, p=0.056) (3) Compared with c2/c2 and rapid acetylation, c1/c1 together with slow acetylation synergetically increased risk of lung cancer 2.83 fold. (4) Smokers with CYP2E1 c1/c1, DD, and NAT2 slow acetylation have 2.365, 1.916, 1.841 fold lung cancer risk than others with c2/c2, CC and NAT2 rapid acetylation, respectively. (5) Han smokers with NAT2 slow acetylation have 1.974 fold lung cancer risk than others with rapid acetylation. Conclusions: Disequilibrium distribution of NAT2 polymorphism was found in lung cancer patients among Han and Mongolian populations. Besides, Han smokers with NAT2 slow acetylation may have higher lung cancer risk compared with rapid acetylation couterparts. CYP2E1 c1/c1, DD and NAT2 slow acetylation, especially combined with smoking, contributes to the development of lung cancer. CYP2E1 c1/c1 or DD genotype and NAT2 slow acetylation have strong synergistic action in increasing lung cancer risk.

• Journal of the Korean Data and Information Science Society
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• 제28권3호
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• pp.597-604
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• 2017

본 연구는 홀스타인 젖소, 923두에 대한 단일염기다형성 (SNP) 42,201개를 이용하여 국내 젖소집단의 유전적 특성 및 유효집단크기를 조사하고자 실시하였다. 염색체별 인접 단일염기다형성간의 평균 연관불평형 ($r^2$)은 0.22로 추정되었으며, 14번 염색체 (0.26)에서 가장 높은 반면, 27번 염색체 (0.17)에서 가장 낮게 나타났다. SNP간의 물리적 거리가 25Kb 미만인 경우에서 $r^2$은 $0.31{\pm}0.33$으로 추정되었으며, SNP간 물리적 거리가 증가할수록 $r^2$은 현저히 감소하였다. SNP간 물리적 거리가 2.5Mb 이상에서의 $r^2$은 0.04로 25Kb 미만인 경우와 비교할 때 0.27 (87.1%) 감소하였다. 국내 홀스타인 젖소의 유효집단크기는 세대수와 비례하여 감소하는 경향을 나타내었으며, 1~5세대에서 110두로 추정되었다.

• 생물정신의학
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• 제16권1호
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• pp.25-36
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• 2009

Objectives : The aim of this study was to investigate the association between Korean ADHD patients and the l/s polymorphism of serotonin transporter(5-HTTLPR). Methods : The study sample consisted of 189 Korean ADHD children diagnosed by Kiddie-Schedule for Affective Disorders and Schizophrenia-Present and Lifetime Version-Korean Version(K-SADS-PL), both parents of ADHD children, and 150 normal children. DNA were extracted from the blood of all samples, and genotyping was done. Based on the allele and genotype information, not only the case-control analysis between ADHD and normal children but also the family-based association test among ADHD children and their parents. Transmission disequilibrium test(TDT) were performed for family-based associated test(number of trio=113). The results of the clinical rating and neuropsychological tests were compared according to the l/s genotype of ADHD children. Results : In case-control analysis, there were no statistically significant difference of l/s gene polymorphism between ADHD and normal children in various kinds of analysis condition. In family-based association study, TDT failed to detect linkage disequilibrium between l/s gene polymorphism and ADHD in whole ADHD families. However, in the families of ADHD inattentive type only(number of trio=23), I allele was transmitted more preferentially in the proband with ADHD even if the number of families was small(${\chi}^2$=4.57, p=.032). In the analysis of the results from the clinical scales and neuropsychological tests in ADHD children, the score of the Novelty- Seeking of ADHD children with l/l genotype was significantly lower than with the other genotypes(F=3.15, p=.047), and that of Self Transcendence was significantly higher(F=4.25, p=.017). Conclusion : The results of this study suggest there were no significant genetic association between the 5- HTTLPR gene polymorphism and Korean ADHD.