ClC-7 is encoded by CLCN7 in humans and the mutations in the CLCN7 gene cause two different types of osteopetrosis: autosomal dominant osteopetrosis type II (OMIM166600) and autosomal recessive osteopetrosis type IV (OMIM611490)1. The gene discussed is CLCN7; the disease is autosomal dominant osteopetrosis 2.