Any autosomal recessive malignant osteopetrosis in which the cause of the disease is a mutation in the CLCN7 gene. The disease is autosomal recessive osteopetrosis 4 (Monarch Disease Ontology term MONDO_0012676). Also known as: CLCN7 autosomal recessive malignant osteopetrosis, CLCN7 autosomal recessive osteopetrosis, CLCN7-related osteopetrosis, OPTB4, autosomal recessive malignant osteopetrosis caused by mutation in CLCN7, autosomal recessive osteopetrosis caused by mutation in CLCN7, autosomal recessive osteopetrosis type 4, infantile malignant osteopetrosis 2.