There are numerous places that a mutation might occur in a chromosome. How
might a mutation to a non-coding region affect gene expression?
A mutation in non-coding DNA could introduce a premature stop codon,
shortening the encoded protein and reducing its expression.
Mutations in non-coding regions could delete the intron sequences of genes,
allowing them to be transcribed more efficiently and increasing expression.
A mutation in a non-coding region could disrupt a regulatory element such as a
promoter, enhancer, or silencer, altering the transcription of an associated gene.
This could increase or decrease gene expression depending on the element
affected.
Mutations in non-coding regions would not affect gene expression since only the
protein coding exon sequences determine expression levels. The non-coding
regions have no impact.
