Osteopetrosis is a collective term for a range of sclerosing bone diseases resulting from absence or functional defects of osteoclasts, which results in bone remodeling defects and increases bone density shown in X-ray. Osteopetrosis is classified in three forms, namely autosomal recessive, autosomal dominant and X-linked inheritance. The most common form of osteopetrosis is autosomal dominant (ADO) inheritance. The typical ADO occurs in late childhood or adolescence and can be subdivided into three subclasses: benign type Ⅰ(ADO-Ⅰ), benign type Ⅱ(ADO-Ⅱ), and benign type Ⅲ(ADO-Ⅲ). Noticeably, it is a disease formerly classified as ADO type Ⅰ, due to gain-of-function mutations of the LRP5 gene. It is mild to severe and is often observed in adults. It is called Albers-Schönberg disease or ADO type Ⅱ, which is caused by the CLCN7 gene. The ADO type Ⅲ is rarely reported. Autosomal recessive osteopetrosis (ARO), also called malignant infantile osteopetrosis, develops soon after birth. ARO is often severe and leads to death if left untreated. About eight genes have been reported to cause the ARO. At present, the treatment of osteopetrosis is mainly symptomatic treatment, hematopoietic stem cell transplantation, in order to minimize the occurrence of complications.

Osteopetrosis; Pathogenic genes; Clinical feature; Inheritance patterns