SERPINH1 and osteogenesis imperfecta: [17] The fact that on the one hand, HSP47 levels were not reduced in our OI patient, and that on the other hand Serpinh1+/- mice were phenotypically normal, despite marked decrease of HSP47 [14], underscores the notion that partially decreased levels of HSP47 alone are not solely responsible for the observed OI phenotype.