If he does, I'd say "now there's a guy with ba**s".
And for all we know, Howard has a venereal disease or SOMETHING and THAT's the reason he doesn't want to "give" his DNA. Pull his medical stuff and we might find out a few things.
" I keep thinking that the doctor who performed a vasectomy on Howard years ago will step forward. "
I really doubt HKS needed a vasectomy. I think he is still a virgin, just like Daniel said he was, in the sense that he hadn't had $EX with a woman. ;)