SNPs in all these regions will modify the DNA sequence. Effects will depend on where exactly the SNP is. I'll summarize the conditions in which effects can be maximum
- Transcription Factors (TFs) binding sites: SNP in the nucleotide positions that bind to the recognition amino acids in the TF
- Epigentic signals: C->X [x: A,G,T] SNPs can disrupt DNA methylation hotspots
- Splicing variants: SNPs at splice donor/acceptor sites can cause intron retention
- microRNA binding sites: SNP in seed region can abolish miRNA targeting
- Coding regions: certain SNPs can create premature stop codons for e.g. CAG (Gln) -> UAG (stop)
there is a lot of work on SNPs. If you search in pubmed for all these categories, you'll get many research articles as well as reviews.