I have .bed, .bim and .fam files for the genetic information of some patients, and I also have the gene expression data from the relevant tissues for the same patients. I have some candidate genes that I want to check whether the expression variation in them is caused by some SNPs in the genetic data. I am familiar with gene expression data, but I have never used genetic data before. I read online that those .bed, .bim and .fam files are PLINK files, but I am really not sure if PLINK program can help me do what I want to do (checking the variation of the genetic content for a specific gene among the samples). Any ideas? Thanks.