I am having a missense mutation at the last base of exon i.e. exon 13 of a gene having 15 coding exons in total. The observed substitution was also confirmed by sequencing mRNA, which is being isolated from whole blood followed by cDNA preparation. In sequencing results it was observed that 77 bases of intron after exon 13 are retained plus there is duplication of exon 15, and this duplicated copy of exon 15 gets merged with exon 13 (as they give overlapping peaks).
Diagrammatic representation of the present scenario is also attached herewith
Kindly help me in deciphering the phenomenon behind it