CLCN7 and autosomal recessive osteopetrosis: In addition, mutations in the vacuolar-H+-ATPase (TCIRG1) and chloride channel-7 (CLC-7; also known as CLCN7) lead to autosomal recessive osteopetrosis due to aberrant lysosomal activity in osteoclasts and consequent defects in bone resorption (Kornak et al., 2001; Susani et al., 2004).