MIP and cataract 5 multiple types: MIP and LIM2: Following the discovery of mutations in the mouse gene for major intrinsic protein (Mip) underlying cataract in the Fraser (CatFr) or Shriveled (Svl) mouse and the lens opacity (Catlop) mouse mutants, originally described in the 1960s, the first mutations in the human counterpart gene (MIP) were discovered in autosomal dominant ‘polymorphic’ and lamellar cataracts linked to chromosome 12q [76,77].