Acid sphingomyelinase deficiency (ASMD), commonly called Niemann-Pick A\/B disease, is an autosomal recessively inherited lysosomal storage disorder resulting from a deficiency in acid sphingomyelinase (ASM) activity [1]. The incidence of this illness is 1 in 250,000 to 400,000 births depending on the subtype. This rare disorder, belonging to sphingolipidoses, is caused by mutations in the sphingomyelin phosphodiesterase 1 gene (SMPD1). ASM deficiency results in the accumulation of the primary ASM substrate, sphingomyelin, and other metabolically related lipids mainly in cells of the monocyte macrophage system in the spleen and lung as well as in hepatocytes.<\/p>\n\n\n\n
These substrates can build up over time, causing progressive cell and tissue damage and functional impairment of multiple organs [2]. The clinical manifestation of sphingolipidosis leads often to misclassification between acid sphingomyelinase deficiency (ASMD) and Gaucher disease (See figure 1). <\/p>\n\n\n\n