CRTAP and osteogenesis imperfecta: In this regard, loss of either CRTAP or P3H1 leads to loss of this complex and its activity, causing a severe recessive form of OI characterized by short stature and brittle bones (Morello et al., 2006; Barnes et al., 2006; Cabral et al., 2007; van Dijk et al., 2009).