I have been using the biomart package to retrieve the exon sequences of certain genes. In particular I am only interested in the first exon of the gene which also includes the 5' UTR.
For this I have used the following code:
ID <- "ENST00000502732.6" sequence <-getSequence(id = ID ,seqType = "gene_exon", type = "ensembl_transcript_id_version", mart = ensembl)
When I look at the resulting dataframe I obtain all the exon sequences. However, the exons are in the wrong order. Meaning that the sequence of exon1 is not necessarily in row 1 (and the rows are not labeled). Since I am particularly interested in exon 1, this is quite annoying as I would need to check the sequences manually again.
Am I missing something here?
Any help is appreciated. Also if there is another way to retrieve sequences of one particular exon it would be great to know.
Thanks in advance!