Question about SNPs

[haho9797]

What if the SNPs fall within gene sequences in the upstream regulatory region?
How to affect the amount and properties of RNA and protein?
What happen if the SNPs happen at other sites (promoter region, 5'UTR, exon, intron, polyA region, 3'UTR)?

[ECO]

All sorts of things depending on the nature and location of the mutation. Up/down regulation is possible from all the things you noted. Not to mention cryptic splicing.

[haho9797]

heterozygous SNP and homozygous SNP

Gernerally, I would know the difference between heterozygous and homozygous SNP. And also, if they are different how they affect RNA and protein level.
I know generally DNA variation can affect RNA and protein, but I don't know regarding heterozygous SNP and homozygous SNP.