PAM is hereditary and another involved family member can be identified in 36% to 61% of cases.[1] Impaired activity of the SLC34A2 gene is responsible for PAM.[2][3][4][8][9][10] The SLC34A2 gene encodes a membrane protein that is expressed primarily in the apical portions of alveolar type II cells[11] and is the most abundant phosphate carrier in the lungs.[5]