Nonsense, frameshift (del · dup · ins), missense and in-frame deletion on a seven-exon toy gene with one long exon, so every NMD rule is visible. Move the variant; watch the PTC and the protein.
learn · coding variants
Where the stop lands decides the allele
Reference. The CDS is read in triplets from AUG to the natural stop. Grey dots mark exon junction complexes, deposited ~20–24 nt upstream of each exon–exon junction; they are how the cell later recognizes a premature stop.