library(org.Hs.eg.db)
    eid <- select(org.Hs.eg.db, "BRCA1", "ENTREZID", "SYMBOL")[["ENTREZID"]]

    library(TxDb.Hsapiens.UCSC.hg19.knownGene)
    txdb <- TxDb.Hsapiens.UCSC.hg19.knownGene
    txid <- select(txdb, eid, "TXNAME", "GENEID")[["TXNAME"]]
    cds <- cdsBy(txdb, by="tx", use.names=TRUE)
    brca1cds <- cds[names(cds) %in% txid]
    
    library(Gviz)
    plotTracks(list(GenomeAxisTrack(), AnnotationTrack(brca1cds))

    library(BSgenome.Hsapiens.UCSC.hg19)
    genome <- BSgenome.Hsapiens.UCSC.hg19
    tx_seq <- extractTranscriptSeqs(genome, brca1cds)
    tx_seq