CLCN7 and Autosomal recessive malignant osteopetrosis: As first discovered in mouse models (12, 13), homozygous loss-of-function (LoF) variants in CLCN7, the gene encoding ClC-7, and in that encoding its obligatory β-subunit OSTM1 (14), cause infantile malignant autosomal-recessive osteopetrosis (ARO) (MIM: 611490 and 259720).