description
This class of mRNAs is expressed from genes that lack introns yet the transcripts end in polyA tails. These tails are formed by a mechanism similar to that for pre-mRNAs containing introns. It is believed that there is a cis-element that replaces the 3' splice site that normally serves to activate polyadenylation of intron containing pre-mRNAs

external resources
NCBI:1269701
REACTOME:R-HSA-111367

genes
NCBP1 , SNRPB , SNRPD3 , SNRPE , SNRPF , SNRPG , NCBP2 , ZNF473 , LSM10 , LSM11 ,