When I run the following R code to convert Ensembl transcript IDs to gene names and Ensembl gene IDs:
mart <- useMart("ensembl", dataset = "hsapiens_gene_ensembl")
ensemble2gene <- getBM(attributes=c("ensembl_transcript_id",
"external_gene_name",
"ensembl_gene_id"),
filters = "ensembl_transcript_id",
values = as.list(transcripts),
mart = mart)
some of rows returned have NA values for both the gene name and Ensembl gene ID. This is a bit odd because for example, one of the transcript IDs with missing gene IDs is ENST00000414213 but when I google it, I find that it corresponds to gene ENSG00000235143 (according to this). Why am I getting missing results in getBM
then? Is it because maybe the transcript is from an old version of the database? If so, is that the only reason or are there other reasons this could be happening?