So, I know on a higher level what an SNP is but I'm a bit confused about the details.
Firstly, our professor said that an SNP has to have at least a prevalence of 1% in the general population to be considered an SNP and not just a mutation. Wikipedia says the prevalence needs to be 0.5%. Is this actually a strictly followed cutoff? And which of the two values is correct?
Secondly, he said that SNPs never cause a disease but can only predispose you to one. However, the wikipedia article mentions thier role in diseases that are clearly caused by single mutations (cystic fibrosis, sickel cell anemia, and beta thalassemia). So, can SNPs cause a disease or not?