Possibly a deficiency in something which often shows up as pale or yellowing leaves. Has it had any fertiliser? (I don't know anything about gooseberries either!)
No expert, but if this is afflicting the lower levels first I'd say it looked like nitrogen defficiency. I have a feeling the potassium defficiency turns leaves brown, but fruit plants certainly do need plenty of potash.
A dose of dried blood might help.
EDIT: could be the same problem with the passion fruit...