SMN2Splicing
SMN2 splicing refers to the processing of SMN2 pre-mRNA into mature transcripts, which largely produce a truncated, nonfunctional SMN protein due to skipping of exon 7. In humans, SMN2 is a paralog of SMN1 located on chromosome 5q13. A single nucleotide difference in exon 7 (a C-to-T transition) alters an exonic splicing regulatory element and biases splicing toward exon 7 exclusion, reducing the amount of full-length SMN (FL-SMN) protein. The resulting SMN2-dependent full-length transcripts constitute only a fraction of the total SMN2 transcripts, with most being SMNΔ7 lacking exon 7.
Splicing of SMN2 is controlled by a balance of cis-acting elements and trans-acting factors. Exonic splicing
Therapeutically, modulating SMN2 splicing aims to increase exon 7 inclusion and thereby raise functional SMN protein