Similar to tourettes syndrome, but the subject will usually blurt out gangster speak rather than swear words. This is common with insecure males who require acceptance from their peer group, believing that going all 'gangsta' on our asses will increase their popularity and thus self esteem.
Customer: Hi there, I was wondering if you could help me. I'm looking for the location of your footwear.
Shop Assistant: Sick. If you follow me, I'll take you to the item.
Customer: Sick? What do you mean by sick?
Shop Assistant: Heavy, ya get meh!?
Customer: Your gangster tourettes syndrome is offputting and unprofessional. I'm going to take my custom elsewhere.