Which Allele is Disease-Linked?

Where can I find information on whether my variant of a gene is the variant linked to a disease or makes me less vulnerable to the disease?

I would like to know also

I ask because when I had a cancer scare, I saw that one of my MtDna mutations was linked to that cancer, but the dangerous allele was a mutation to C, while luckily my allele was T.

It depends on what disease you are talking about. You have many mutated cells but you have to be more specific in your question. Once you have the disease or gene, then either use the sandbox feature or You do a ton of googling and reading. You can also go to snpedia and type in the gene name. Good luck.