<unk>  <unk>  is a rare, inherited disorder of lung phosphate balance that is associated with small stone formation in the airspaces of the lung. Mutations in the gene SLC34A2 result in loss of a key sodium, phosphate co-transporter (called Npt2b), known to be expressed in distal alveolar type II cells, as well as in the mammary gland, and to a lesser extent in intestine, kidney, skin, prostate and testes. As the disease progresses, the lung fields become progressively more dense (white) on the chest xray, and low oxygen level, lung inflammation and fibrosis, elevated pressures in the lung blood vessels, and respiratory failure ensue, usually in middle age. The clinical course of<unk>  can be highly variable, with some patients remaining asymptomatic for decades, and others progressing more rapidly. There is no effective treatment, and the mechanisms of stone formation, inflammation and scarring are not known.
Pulmonary alveolar microlithiasis
Pulmonary interstitial emphysema
Pulmonary hyalinizing granuloma
Granulomatous–lymphocytic interstitial lung disease
Pulmonary alveolar proteinosis
Focal lung pneumatosis
Usual interstitial pneumonia
Cryptogenic organizing pneumonia