Hi, I have a huge list of gene names, and I want to assign the ID for each gene. I tried the following code, and it kind of worked, but the problem was that it created extra IDs (more than the available genes) --> causing misalignment between names and IDs

CODE

library("org.Hs.eg.db")

a <- read.csv("filename.csv",TRUE,",")

y=as.character(a$Gene.refGene) #column name is Gene.refGene

gene=y

output = unlist(mget(x=gene,envir=org.Hs.egALIAS2EG,ifnotfound=NA))

write.csv(output, file = "output.csv") #write the IDs which is the output in a csv file

Is there any other way to get the gene IDs? or any suggestion on how to modify the code? your help is highly appreciated!