I am so sorry to hear that both your boys have been diagnosed. If this helps, although I believe there are different degrees of Dent's disease, my son, who is now 19, and diagnosed at 3, had a wonderful childhood (and is still having a great and normal time at university it seems), except probably for his mom stressing about him taking too much sodium in his diet, and having to go to the doctor more frequently than his friends. He also takes hydrochl. and K-Citra. He is now an active, bright young man (a little absent minded and disorganized but I don't know if it is his age or the disease). He hardly grew around ages 10 to 12, and therefore took growth hormone from ages 12 to 18, and only stopped because he's away from home now. The hormones must have worked because, even though we are all short at home (my husband, his 2 younger sisters and myself) he is now the tallest at 5 ft. 9. My husband is 5 ft 7 and I am 5 ft. So, taking meds, growth hormones, doctors' appointments will be a part of your life, but, at least I try to think the positive is that nowadays there is dialysis and transplants, whereas (the same as bluejeanne's family) when my dad died, the doctors (Harvard related) did not know what it was and that it was hereditary and also simply told my mother it was a terminal disease.
My only advice from my own experience is not to stress too much if you miss one dose of meds or hormones, or if they eat unhealthy. Overstressing doesn't solve anything; just get back on track. And enjoy your boys... as the old cliché says: they grow up so quickly! And let us just hope that a cure will be found for Dent's in the near future.