Homozygosity for FARSB mutation leads to Phe-tRNA synthetase-related disease of growth restriction, brain calcification, and interstitial lung disease.
Recently, biallelic FARSB defects have been shown to cause severe growth restriction with combined brain, liver and lung involvement (Rajab interstitial lung disease [ILD] with brain calcifications).
<b>Rationale:</b> Pulmonary alveolar proteinosis (PAP) is characterized by filling of the alveolar spaces by lipoprotein-rich material of ill-defined composition, and is caused by molecularly different and often rare diseases that occur from birth to old age.<b>Objectives:</b> To perform a quantitative lipidomic analysis of lipids and the surfactant proteins A, B, and C in lavage fluids from patients with proteinosis of different causes in comparison with healthy control subjects.<b>Methods:</b> During the last two decades, we have collected BAL samples from patients with PAP due to autoantibodies against granulocyte-macrophage colony-stimulating factor; genetic mutations in CSF2RA (colony-stimulating factor 2 receptor α-subunit), MARS (methionyl aminoacyl-tRNA synthetase), FARSB (phenylalanine-tRNA synthetase, β-subunit), and NPC2 (Niemann-Pick disease type C2); and secondary to myeloid leukemia.