Off topic:Can I get the SNPs from my RNA-Seq fastq files?

Question

[Pin.Bioinf]

Hello,

I was asked if I can know/obtain the SNPs in the samples we sequenced with RNA-Seq. Can I do it from the .fastq files? How can I do it? Also, these fastq files mapped agains reference with 50M reads, would that be enough? Do I need to compute coverage?

Thank you