Retained Intron through Translation

[cgh24]

What happens to a protein sequence when an intron is not spliced out in the maturation of an mRNA strand?

All I could come up with was that you would get a garbage protein with incorrect amino acids once the ribosome got to the intron. I guess also if the intron length (in nucleotides) were a multiple of 3 you would just get an extra domain in the normal protein. But this is apparently an incomplete answer. I've looked through articles and my class notes and textbook (The RNA World) but I can not come up with any other ideas. Does anyone have other ideas? Thanks!

[jonmoulton]

When an intron is included, you are likely to have a stop codon in-frame in the intron. This triggers nonsense-mediated decay of the mRNA.

Frameshifting downstream sequence by including an intron with a number of bases not evenly divisible by three will also likely bring a stop codon in-frame in the downstream exon, likely also triggering nonsense-mediated decay of the mRNA.