A reader (who wants me to write an article on autism and paternal age-- I swear I'm getting to it) sent me a reference to a 2007 article finding an increased rate of schizophrenia in those born to parents who were dry cleaners (all Jewish, negating a racial association).  The authors speculate it's tetrachloroethylene exposure.

There were 4 cases of schizophrenia, out of 144 dry cleaning families.  What's interesting is that in 3 of the schizophrenia cases, the father was the dry cleaner. 

How does it happen? There are two possibilities: one is that tetrachloroethylene is neurotoxic in developing fetuses, so the dad must have somehow brought it home with him to the pregnant mom.  Or, it affects male sperm/ germ cells.

As for Cho, I don't know if his parents were dry cleaners in Korea, or if they started when they all came to the U.S.  But something worth investigating.

BTW: not that this would excuse him even if it were true. 

To Leslie, the reader: if you want credit, put in a comment and I'll put your contact info up here.)