OSTM1 and osteopetrosis: OSTM1 is predicted to be a glycosylated, single-pass transmembrane protein and mutations in OSTM1, like mutations in CLC-7, can lead to osteopetrosis and neurodegeneration in humans and mice (Chalhoub et al., 2003; Kasper et al., 2005; Kornak et al., 2001; Lange et al., 2006; Majumdar et al., 2011; Pressey et al., 2010).