Chromosome 22 LD Map Comparison between Korean and Other Populations

Single nucleotide polymorphisms (SNPs) are the most abundant forms of human genetic variations and resources for mapping complex genetic traits and disease association studies. We have constructed a linkage disequilibrium(LD) map of chromosome 22 in Korean samples and compared it with those of other populations, including Yorubans in Ibadan, Nigeria (YRI), Centred'Etude du Polymorphisme Humain (CEPH) reference families (CEU), Japanese in Tokyo (JPT) and Han Chinese in Beijing (CHB) in the HapMap database. We genotyped 4681 of 111,448 publicly available SNPs in 90 unrelated Koreans. Among genotyped SNPs, 4167 were polymorphic. Three hundred and five LD blocks were constructed to make up 18.6% (6.4 of 34.5 Mb) of chromosome 22 with 757 tagSNPs and 815 haplotypes(frequency > or = 5.0%). Of 3430 common SNPs genotyped in all five populations, 514 were monomorphic in Koreans. The CHB + JPT samples have more than a 72% overlap with the monomorphic SNPs in Koreans, while the CEU + YRI samples have less than a 38% overlap. The patterns of hot spots and LD blocks were dispersed throughout chromosome 22, with some common blocks among populations, highly concordant between the three Asian samples. Analysis of the distribution of chimpanzee-derived allele frequency (DAF), a measure of genetic differentiation, Fst levels, and allele frequency difference (AFD) among Koreans and the HapMap samples showed a strong correlation between the Asians, while the CEU and YRI samples showed a very weak correlation with Korean samples. Relative distance as a quantitative measurement based upon DAF, Fst, and AFD indicated that all three Asian samples are very proximate, while CEU and YRI are significantly remote from the Asian samples. Comparative genome-wide LD studies provide useful information on the association studies of complex diseases.

Chromosome 22 LD Map Comparison between Korean and Other Populations

Single nucleotide polymorphisms (SNPs) are the most abundant forms of human genetic variations and resources for mapping complex genetic traits and disease association studies. We have constructed a linkage disequilibrium(LD) map of chromosome 22 in Korean samples and compared it with those of other populations, including Yorubans in Ibadan, Nigeria (YRI), Centred'Etude du Polymorphisme Humain (CEPH) reference families (CEU), Japanese in Tokyo (JPT) and Han Chinese in Beijing (CHB) in the HapMap database. We genotyped 4681 of 111,448 publicly available SNPs in 90 unrelated Koreans. Among genotyped SNPs, 4167 were polymorphic. Three hundred and five LD blocks were constructed to make up 18.6% (6.4 of 34.5 Mb) of chromosome 22 with 757 tagSNPs and 815 haplotypes(frequency > or = 5.0%). Of 3430 common SNPs genotyped in all five populations, 514 were monomorphic in Koreans. The CHB + JPT samples have more than a 72% overlap with the monomorphic SNPs in Koreans, while the CEU + YRI samples have less than a 38% overlap. The patterns of hot spots and LD blocks were dispersed throughout chromosome 22, with some common blocks among populations, highly concordant between the three Asian samples. Analysis of the distribution of chimpanzee-derived allele frequency (DAF), a measure of genetic differentiation, Fst levels, and allele frequency difference (AFD) among Koreans and the HapMap samples showed a strong correlation between the Asians, while the CEU and YRI samples showed a very weak correlation with Korean samples. Relative distance as a quantitative measurement based upon DAF, Fst, and AFD indicated that all three Asian samples are very proximate, while CEU and YRI are significantly remote from the Asian samples. Comparative genome-wide LD studies provide useful information on the association studies of complex diseases.

Clinical effect of montelukast in exercise-induced asthma / 천식및알레르기

BACKGROUND: Patients with bronchial asthma frequently have exercise-induced bronchocon striction. Exercise-induced bronchoconstriction limits the activities important for physical and social development in children. Leukotriene receptor antagonist has been shown to protect against exercise-induced bronchoconstriction. The purpose of this study is to determine the effect of montelukast in protecting or controlling exercise-induced asthma. METHOD: 22 patients were enrolled and received montelukast(5 mg/day) for 2 months. Exercise challenges were performed before and after treatment and medication was not given for at least 48 hours before follow-up test. The form of exercise was free running for 8 minutes. The respiratory symptom scores, maximum percent fall in FEV1 from pre-exercise baseline and time to recovery of FEV1 to within 10% of pre-exercise baseline were evaluated. RESULTS: The respiratory symptoms score was siginificantly improved after 2 months of therapy(p<0.05). The maximum percent fall in FEV1 after exercise and the time from maximum percent fall in FEV1 to return to within 10 precent of pre-exercise FEV1 were also siginificantly improved after 2 months of therapy(p<0.05). In 3 patients with exercise-induced asthma, the maximum percent fall in FEV1 was decreased after 2 months of therapy, but was increased after follow-up 2 months without therapy. CONCLUSION: Montelukast, a leukotriene-receptor antagonist, is effective for protection and control of exercise-induced asthma in children.