Penicillin
From SNPedia
Response to penicillin, and in particular having an allergic reaction to penicillin, is thought to be at least partly genetic.
Studies to date (PMID 18538381, PMID 16315031) have focused on SNPs in various interleukin genes. Little of statistical significance has come out of these studies so far, however, and the best quasi-genetic method of predicting allergic reactions to penicillin remains having it run in the family.
