Wow, I have no idea what to put on this page. For the moment, no children get renal disease and it'll be fine. Unfortunately, that's not true but it still doesn't help me write this page. OK, I'll go and read some stuff and see what I come with. I'll probably end up looking something like this:
Main problems in renal medicine
The problems in paediatric renal disease that you definitely need to know about are UTI, nephrotic syndrome and Henoch-Schönlein purpura (as this is the primary cause of acute nephritis). You will also need to know about some causes of blockage of the urinary tract.
Learn about these as they are what you might refer to as well important in the Queen's English.
Other renal problems
Almost everything else can come under the umbrella of "other". This includes things like renal failure, stones, masses and magical things like haemolytic uraemic syndrome but they all pretty much come under uncommon renal problems.