CLCN7 and Albers-Schönberg osteopetrosis: The G215R mutation in CLCN7, for example, leads to autosomal dominant osteopetrosis type 2 that does not abolish the transport function of the channel but rather causes a severe trafficking defect with the G215R-CLCN7 mutation rendering CLCN7 retention in the ER (Schulz et al., 2010).