The condition tells us something about the mechanism for the development of the variations which supposedly led to evolutionary progress. It doesn't work.
DNA is unstable, various environmental insults damage it. However, there are sophisticated mechanisms that repair it. In XP they malfunction, leading to death. The questions for evolutionists, should they dare to attempt to answer it, is how did this mechanism arise in the first place? It cannot have preceded the DNA that codes for it.
Here's an extract from a science paper
ã1998 by Cell Press