TIMP3 and Sorsby fundus dystrophy: All TIMP-3 mutations that are acknowledged to cause SFD introduce an unpaired cysteine residue and promote the formation of higher molecular weight TIMP-3 oligomers: one at the n-terminus (S38C) and six at the C-terminus (S156C, G166C, G167C, Y168C, Y172C and S181C) [51,52].