Neural impairments, typically due in autosomal recessive osteopetrosis to nerve compression syndromes, in this form can be aggravated by primary hippocampal, cortical and retinal degeneration caused by lysosomal storage disease.30 The CLCN7 gene is aplosufficient, and single allele loss of function mutant carriers display no symptoms whatsoever.31,32. Here, CLCN7 is linked to autosomal recessive osteopetrosis.