Osteopetrosis Autosomal Dominant Type II OMIM

Description: #166600 OSTEOPETROSIS, AUTOSOMAL DOMINANT, TYPE II; OPTA2 Alternative titles; MARBLE BONES, AUTOSOMAL DOMINANT OSTEOSCLEROSIS FRAGILIS GENERALISATA ALBERS-SCHONBERG DISEASE, AUTOSOMAL DOMINANT Gene map locus 16p13 autosomal dominant osteopetrosis type II can result from mutation in the CLCN7 gene (602727). DESCRIPTION Autosomal dominant osteopetrosis type II is characterized by sclerosis, predominantly involving the spine, the pelvis, and the skull base. CLINICAL FEATURES Salzano (1961) reviewed dominant cases of osteopetrosis and found that fragility of bones and dental abscess are leading complications. A more malignant form, inherited as a recessive (259700), causes anemia and early death from interference with the bone marrow. Welford (1959) described 14 affected male members of 5 generations of a family. All affected persons had facial paralysis beginning usually at about the age of 12 years. Main clinical features are fractures and osteomyelitis, especially of the mandible. By x-ray the vertebral bodies have a characteristic 'sandwich' appearance resulting from sclerosis of the upper and lower plates with intervening less dense area. Long bones of the extremities may show a 'bone-within-bone' appearance. Osteosclerosis, sometimes termed osteopetrosis, is a feature of pycnodysostosis (265800). Follow-up on the family reported by Ghormley (1922) was provided by McKusick et al. (1961). Johnston et al. (1968) studied 2 families. In one pedigree, the disorder was twice nonpenetrant. Elevated acid phosphatase was a feature in all but one of the affected persons.