Meaning of letter "c" in description of mutation: "Homozygous c.195C>G; (p.Cys65Trp)"
I typed "c dna mutation" in Google and this article was the first hit:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1867422/

The "c" denotes coding DNA, which given the context of the amino acid mutation having the letter "p", this makes sense.