زهرا معزالدینی - ۱گروه زیست شناسی،دانشکده فنی و مهندسی،دانشگاه علم و هنر
مرتضی بیطرف ثانی - ۲گروه مطالعات دامی، مرکز تحقیقات کشاورزی و منابع طبیعی استان یزد
سید محسن میراسمعیلی - ۳گروه زیست شناسی، دانشکده فنی و مهندسی، دانشگاه علم و هنر
محمد ایرانمنش

Background: the possibility of identifying the effects of XbaI SNP ( rs9340799) of estrogen receptor gene (ESR1) a genetic marker for CAD, was investigated by genomic simulation studies. the determination of the sample size required for GWAS, due to its costs of performing, is necessary.Methods: GWAsimulator and R (SNPassoc package) was used to simulate genomic data and association analysis. To investigate LD structure, haploview software was used. The result is that the prevalence of the disease, the odds ratio and the number of markers have a significant effect on determining the size of the sample required for GWAS. The prevalence of the disease and Odds ratio are inversely proportional to the number of samples needed for association studies. Results: XbaI is possible in a study with 100 markers, with at least 500 patients. By increasing the number of markers to 20269 with an prevalence of 5%, at least 2,000 patients and 15% with 1500 can be significant.Conclusion: In GWAS, with an increase in the number of markers, in order to achieve significant differences in the frequency of the marker in the two groups of case and control, more samples are needed.

Genome Wide Associated studies,coronary artery disease, sample size,prevalence