Albers-Schönberg Osteopetrosis

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Retrieved

2021-01-23

Source

Orphanet

Trials

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Genes

CLCN7, TNFSF11, FERMT3, IFNG

Drugs

Allogeneic multi-virus specific T lymphocytes targeting BK virus, cytomegalovirus, human herpesvirus-6, Epstein Barr virus and adenovirus, Interferon gamma 1b ( ACTIMMUNE, IMUKIN ), haematopoietic stem cells and blood progenitors umbilical cord-derived expanded with (1R, 4R)-N1-(2-benzyl-7-(2-methyl-2H-tetrazol-5-yl)-9H-pyrimido[4,5-b]indol-4-yl)cyclohexane-1,4-diamine dihydrobromide dihydrate

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A sclerosing disorder of the skeleton characterized by increased bone density that classically displays the radiographic sign of ''sandwich vertebrae'' (dense bands of sclerosis parallel to the vertebral endplates).

Epidemiology

The prevalence is estimated to be 1/20,000.

Clinical description

Onset of the disease is typically in late childhood or adolescence. The main manifestations are confined to the skeleton, including fractures, scoliosis, hip osteoarthritis and osteomyelitis, particularly affecting the mandible in association with dental abscess or caries. Cranial nerve compression is a rare but important complication, with hearing and visual loss affecting around 5% of individuals. Moderate bone marrow failure is described occasionally.

Etiology

The disease is caused by heterozygous mutations in the chloride channel 7 (ClCN7) gene (16p13).

Diagnostic methods

Diagnosis is based on clinical findings and largely depends on the radiographic appearance of the skeleton. Genetic testing is available and can be used to confirm the diagnosis.

Differential diagnosis

Differential diagnosis includes other subtypes of osteopetrosis, fluorosis, beryllium, lead and bismuth poisoning, myelofibrosis, Paget's disease (sclerosing form) and malignancies (lymphoma, osteoblastic cancer metastases) (see these terms).

Antenatal diagnosis

Antenatal diagnosis is possible if the mutation causing the condition in the family is known.

Genetic counseling

Albers-Schönberg osteopetrosis is transmitted in an autosomal dominant manner. Genetic counseling should be offered to families. Each child of an affected individual has 50% risk of being affected. The parents of the proband should be carefully evaluated for signs of osteopetrosis, including radiographic studies of the skeleton.

Management and treatment

At present, there is no effective medical treatment for osteopetrosis. Management is supportive and aims at providing multidisciplinary surveillance and symptomatic treatment.

Prognosis

Clinical manifestations may worsen over time but life expectancy is usually normal.