Genetic testing for developmental delays?

What kind of things are they testing for?

My son was diagnosed with Autism and his Neuro ordered a bunch of tests and I'm kindafreaking out about all the scenarios in my head. I'm worried the MRI will show cancer. I'm worried he has some scary genetic disorder.

They did it for my son for his developmental delays, they said it was just routine to check and in his case they were looking for an explanation for his delays. We haven't done the MRI yet but it's coming up, all his genetic testing came back fine. Don't go off googling, you'll start diagnosing him with a million different things, staring at his features trying to see if his ears are too low, ect, ect. It's just going to freak you out and it's probably nothing!