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OBJECTIVE Chromosome 22q11 has been implicated as a susceptibility locus of schizophrenia. It also contains various candidate genes for which evidence of association with schizophrenia has been reported. To determine whether genetic variations in chromosome 22q11 are associated with schizophrenia in Koreans, we performed a linkage analysis and case-control association study. METHODS Three microsatellite markers within a region of 4.35 Mb on 22q11 were genotyped for 47 multiplex schizophrenia families, and a non-parametric linkage analysis was applied. The association analysis was done with 227 unrelated patients and 292 normal controls. For 39 single nucleotide polymorphisms (SNPs) spanning a 1.4 Mb region (33 kb interval) containing four candidate schizophrenia genes (DGCR, COMT, PRODH and ZDHHC8), allele frequencies were estimated in pooled DNA samples. RESULTS No significant linkage was found at any of the three microsatellite markers in single and multi-point analyses. Five SNPs showed suggestive evidence of association (p

Introduction Although several studies have explored craving for certain drugs, there is limited data describing the relationship between alcohol and nicotine craving from a multidimensional perspective among individuals with comorbid nicotine dependence (ND) and alcohol dependence (AD). Methods We compared a group of male patients diagnosed with ND and AD (n = 160) to a group of male patients diagnosed with ND only (n = 235). Smoking- and drinking-related clinical features were measured, including craving levels and the Nicotine Dependence Syndrome Scale (NDSS), which is a multidimensional questionnaire measuring ND. Subsequently, we studied factors that influenced smoking and alcohol craving in the ND and AD group. Results Regarding the NDSS, the sum, priority and tolerance scores were significantly higher in the ND and AD group compared with the ND only group (P

The objective of this study was to characterize the familial associations of symptoms or symptom dimensions of schizophrenia, as a component of the effort to delineate suitable phenotypic markers under the homogenous genetic control.Clinical symptoms of the patients were evaluated on a lifetime basis, with the Korean version of the Diagnostic Interview for Genetic Studies and the Krawieka scale. Our sample consisted of 54 sibling pairs who were concordant for Diagnostic and statistical manual of mental disorder-IV schizophrenia or schizoaffective disorder.At the individual symptom level measured by the Diagnostic Interview for Genetic Studies, we observed a statistically significant degree of concordance within the sibling pairs for auditory hallucination (kappa=0.600, chi(2)=15.193, P=0.000). The within-sibling resemblance of this symptom was also indicated by the results of correlation analyses of individual items of the Krawiecka scale (partial correlation coefficient=0.423, P=0.005). Among the individual symptoms or symptom dimensions of the Krawiecka scale, the 'anxious' (partial correlation coefficient=0.469, P=0.001) and the 'affective dimension' (including the items of 'anxious' and 'depressed') (partial correlation coefficient=0.436, P=0.003) were also determined to indicate significant intra-pair correlations after controlling for potential confounding variables, such as sex, duration of illness, and age of onset.The results of this study suggest that familial factors, possibly genetic factors, contribute a liability to the development of auditory hallucinations. This symptom might then prove useful as a phenotype marker in future genetic studies.

Chromosome 1q contains a few loci for which modest evidence of linkage with schizophrenia has been reported in several independent studies. However, markers showing the peak linkage signal are dispersed over a large chromosomal region. In addition, inconsistent findings have been generated from different populations or different subgroups of the same populations. The purpose of the current study is to determine whether those loci are linked to schizophrenia in the Korean population. We investigated 46 Korean multiplex schizophrenia families, initially using 11 microsatellite markers spanning around 91 cM region of 1p22∼42. In a non-parametric linkage analysis, D1S249 located on 1q32.1 showed statistical evidence suggestive of linkage. At the second stage analysis for narrowing down the region, four additional nearby markers were genotyped. In the single point analysis, we found another suggestive linkage signal at D1S2891. The highest NPL score of 2.67 (P = 0.0039) was obtained in the multi-point analysis. This study provides supportive evidence for linkage of chromosome 1q32 with schizophrenia. © 2006 Wiley-Liss, Inc.

Although several studies have explored craving for certain drugs, there is limited data describing the relationship between alcohol and nicotine craving from a multidimensional perspective among individuals with comorbid nicotine dependence (ND) and alcohol dependence (AD).We compared a group of male patients diagnosed with ND and AD (n = 160) to a group of male patients diagnosed with ND only (n = 235). Smoking- and drinking-related clinical features were measured, including craving levels and the Nicotine Dependence Syndrome Scale (NDSS), which is a multidimensional questionnaire measuring ND. Subsequently, we studied factors that influenced smoking and alcohol craving in the ND and AD group.Regarding the NDSS, the sum, priority and tolerance scores were significantly higher in the ND and AD group compared with the ND only group (P0.000, P0.000 and P = 0.001, respectively). In the comorbid group, regression analyses revealed that alcohol craving and Fagerstrom Test for Nicotine Dependence (FTND) scores contributed to nicotine craving (beta coefficient = 0.37, P = 0.005 and beta coefficient = 0.35, P = 0.026, respectively) and these two factors explained 36% of the variance). Nicotine craving appeared to be the only factor that contributed to alcohol craving (beta coefficient = 0.35, P = 0.002), and nicotine craving explained 16% of the variance.This study may help clarify the clinical relationship between comorbid alcohol and nicotine dependence and help guide the development of effective treatment strategies for ND and AD patients.

The present study reports the results of a genome-wide SNP linkage scan for schizophrenia in the Korean population. Fifty-six multiplex schizophrenia families were analyzed. Clinical evaluations on all subjects were consistently performed by raters in a single research team. Multipoint non-parametric linkage analysis was performed, and empirical simulations were generated to determine genome-wide significance. The authors found genome-widely significant evidence of linkage for schizophrenia to chromosomes 2p24.3 (NPL Z = 3.18) and 6q27 (NPL Z = 2.90). Six other chromosomal regions, that is, 3q24, 13q12.3, 18q22.3, 20p12.2, 4p14, and 1p36.12, yielded NPL Z scores of above 2.0 for either broad or narrow phenotype classes. Although linkage to these loci has not received prominent attention in studies on Caucasian families, multiple overlaps were observed between our loci (on 2p, 3q, and 13q) and linkage peaks generated from extended families in various isolated populations. Fine mappings and the detection of candidate genes within these regions are warranted.

MethodsZZNinety-seven nurses newly employed in a Seoul Medical Center from April 2014 to September 2015 were included to the study. Before beginning employment, all subjects were asked to complete a sociodemographic questionnaire and Temperament and Character Inventory (TCI). After they were employed for a month, we administered a heart rate variability test and Korean Occupational Stress Scale (KOSS).

Chromosome 8p21-12 has been reported to be a susceptibility locus for schizophrenia based on genome-wide linkage scans. After neuregulin 1 (NRG1) was identified as a positional candidate gene for schizophrenia in this locus, several independent association studies have reported controversial results. To determine whether genetic variations in this locus are associated with schizophrenia in the Korean population, we investigated multiplex families and unrelated patients using linkage and association analyses. Seven microsatellite markers in 8p21-12 were genotyped for 40 families with schizophrenia, and a non-parametric linkage analysis was applied. The association study was performed with 242 unrelated schizophrenia patients and the same number of normal controls for three single nucleotide polymorphisms (SNPs), two microsatellite markers and their haplotypes. A significant linkage signal was observed on D8S1769, which is located 352 kb upstream of the 5′ end of the first exon of NRG1 for two (“narrow” and “narrow with auditory hallucination (AH)”) of the three adopted phenotype classes. In the association study, the G allele of SNP8NRG241930 was significantly in excess in the subgroup of patients with AHs. We also found haplotypes which were associated with schizophrenia with a protective effect. This study provides additional suggestive evidence for both the linkage and association of genetic variations on 8p12, a locus of NRG1, with schizophrenia. NRG1 might either play a role in the predisposition to schizophrenia or be in linkage disequilibrium (LD) with a causal locus of this illness. © 2006 Wiley-Liss, Inc.