Pulmonary storage with emphysema as a sign of Niemann-Pick type C2 disease(second complementation group). Report of a case

A case is described of Niemann-Pick type C2 disease presenting an infantile pneumopathic phenotype known to occur in this recently established, second , minor complementation group of Niemann-Pick type C (NPC) disease. However , the pulmonary involvement was unique, being dominated, in addition to the usual storage macrophage infiltration of the alveolar and septal compartme nts, by irregular emphysema attributed to storage cell migration into the b ronchiolar lumen. The latter modified considerably the X-ray findings and h indered the initial clinical diagnosis. Otherwise, the storage phenotype, i ncluding the range of stored lipids, storage distribution, and cell and org an pathology, was found to be identical to that in the whole Niemann-Pick t ype C disease group dominated by NPC1. The biochemical findings (cholestero l esterification level) corresponded to the classical biochemical phenotype .. Emphysema should thus be considered as a variant of the pulmonary NPC2 s torage process, governed most probably by an epigenetic mechanism responsib le for storage, macrophage migration into the bronchiolar compartment.