Is there something amounting to "check sums" in genetic code?

Humans use checksums for many different applications in informational processes.

Genetic code is used as a "program" to synthesize proteins, so it could (I’m a layman when it comes to biology!) make sense that its integrity is protected in some way. And since there are just so many cells in a human body a few "retries" could be attempted when encountering bad strands in one source during DNA replication or protein biosynthesis.

Because minute mutations can have a big effect, I was wondering if there is any mechanism that amounts to check sums in genetic code? And if (no) such thing has been discovered as of yet, is there any theory as to why (not)?