Two common less severe disease-causing variants are Gly624Asp in COL4A5 (which is associated with late onset kidney failure) [22] and Leu1474Pro in COL4A3 (which may not on its own cause microscopic haematuria, but can be associated with kidney failure when found together with a second disease-causing COL4A3 variant in trans, or due to digenic inheritance). Here, COL4A5 is linked to kidney failure.