Severe neonatal or infantile forms have the worst prognosis (16), while CLCN7 variants causing osteopetrosis late‐onset form type 2 (OPTA2) (formerly autosomal dominant type II osteopetrosis (ADOII) have a varied clinical phenotype, including asymptomatic forms (17). This evidence concerns the gene CLCN7 and autosomal dominant osteopetrosis 2.