I think if I recall when one parent has SZ the risk is 10 percent. Here's a schizophrenia and heredity guide.
Schizophrenia runs in my family on my mother's mother's or maternal grandmother's side of the family. So it is definitely possible.
The goal is not to worry over some imagined outcome. It is also possible the son WON'T develop schizophrenia. By all means, educate yourself about the schizophrenia early warning signs. Yet by no means worry yourself without reason.
I was diagnosed with schizophrenia when I was 22, I have a Masters degree and I'm the community leader of this Web site as well as holding down two other jobs, one a full-time day job.
So rather that worry, look on the bright side. Immediate or early intervention with SZ medication and therapy such as cognitive behavior therapy (CBT) will speed along the recovery when someone first exhibits the symptoms of this illness.
Recovery is possible. I wouldn't get alarmed by any statistics.