Table 3.
Genetic causes of osteopetrosis
| Genetic subtype | Gene | Function | Frequency | Disease severity |
|---|---|---|---|---|
| Autosomal recessive |
CAII | Produces H+ in cytoplasm | < 5% of patients with severe osteopetrosis |
Somewhat more severe than the other types |
| Autosomal recessive |
TCIRG1 | Proton pump | 60% of patients with severe osteopetrosis |
Severe |
| Autosomal recessive |
CLCN7 | Chloride channel | 15% of patients with severe osteopetrosis |
Either severe or intermediate |
| Autosomal recessive |
g1/g1 | Unknown | < 5% of patients with severe osteopetrosis |
Extremely severe |
| Autosomal recessive |
TNFSF1 1−/− | RANKL | Rare | Severe |
| Autosomal dominant |
CLCN7 | Chloride channel | Rare; 1 in 100,000 to 1 in 500,000 |
Mild delayed onset |