Hermansky-Pudlak syndrome is a heterogeneous group of autosomal recessive disorders associated with accumulation of a ceroid-like substance in lysosomes of a variety of tissues. It is characterized by albinism, bleeding tendency associated to poor platelet aggregation and systemic complications associated to lysosomal dysfunction. A chronic inflammatory process may explain the progressive development of ILD and fibrosis [132] . Familial hypercalcemia with hypocalciuria Familial hypercalcemia with hypocalciuria is caused by autosomal dominant loss-of-function mutations in the gene encoding the calcium-sensing receptor (CASR), a G-protein coupled membrane receptor expressed in many tissues [133] . Loss-of-function mutations in CASR impair the feedback inhibition of parathyroid hormone secretion in response to a rise in the blood calcium concentration. The result is hypercalcemia associated with inappropriately normal or mildly elevated levels of parathyroid hormone. In the kidneys, mutations in CASR prevent the feedback inhibition of calcium reabsorption in situation of hypercalcemia, leading to relative hypocalciuria. Respiratory symptoms are usually mild and associated with reduction in the lung diffusion capacity. Lung histology indicates the presence of foreign body giant cells and mononuclear cells infiltrating the alveolar interstitium, without circumscribed granulomas.