Rare periodic fevers can be a minefield. A good amount of research has been dedicated to understanding these conditions and the genetics behind them; yet there is still so much more to fully understand about these diseases – even by scientists! A lot of it comes down to differences in the genetic recipe (DNA) between people. DNA differences between people are natural - individuals are rarely identical - but every once in a while a tiny change (1 change in 3 billion base pairs of DNA) has big downstream effects (like pushing over the first card in a long line of branching cards). In this science section of the website, we describe highlights of the current understanding of the science behind the tiny DNA change(s) that lead to rare periodic fevers, and we describe some of the diseases themselves – CAPS, SJIA, FMF, TRAPS, HIDS/MKD, and Gout. Explore to find out more.