I was looking at the topgear website and came across these posts on a Randy thread by someone with a username "Lution":

Feb. 27, 2011
I played in a couple of bands with Randy's son, Dana, in the early 90s. Dana plays the drums and is a monster player. Tremendous talent. I have also recently played in a couple of bands with Randy's other son, Eric. Eric is also a drummer and is quite talented himself. I have been fortunate enough to meet and talk with Randy on several occasions. He's always friendly and kind to me. Super cool guy and really cool family.
Apr. 24, 2012
The drummer for my cover band (Bionic Freddy) is Randy's son, Eric. Eric and I have been good pals for a long time. I asked him a couple of weeks ago how his dad was doing. He said Randy has been taking it easy lately. No shows or tours at the moment.
I had read that one of Randy's sons played the drums in high school, but I didn't know they had actually been in active bands. Musical talent definitely runs in his family.