RAINBOWR(Reliable Association INference By Optimizing Weights with R) is a package to perform several types of GWAS as follows.
RGWAS.normal functionRGWAS.multisnp function (which tests multiple SNPs at the same time)RGWAS.epistasis (very slow and less reliable)https://github.com/KosukeHamazaki/RAINBOWR
https://journals.plos.org/ploscompbiol/article?id=10.1371/journal.pcbi.1007663